discovery-api/Overview.src.html
author Rich Tibbett <richt@opera.com>
Thu, 29 Aug 2013 11:01:15 +0200
changeset 447 5e36d90b8960
parent 441 b4b2569b4e9b
child 448 865b6f93faac
permissions -rw-r--r--
Replace numeric error codes with string-based error types and fold the NavigatorNetworkServiceError interface in to DOMError (therefore, removing NavigatorNetworkServiceError from spec)
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<!DOCTYPE html>
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<!--
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  THIS IS THE WORKING VERSION OF THE CURRENT SPECIFICATION!
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  This specification is built using ReSpec.js <http://dev.w3.org/2009/dap/ReSpec.js/documentation.html>
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  From time to time it's necessary to HTML5 Tidy this document using the tool @ <http://w3c.github.com/tidy-html5/>.
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  The command used to format this document (Overview.src.html) is as follows (replacing all = signs with - signs!):
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  @> tidy ==new-blocklevel-tags section ==char-encoding utf8 ==tidy-mark no ==indent yes ==indent-spaces 2 ==indent-attributes yes ==wrap 120 ==fix-bad-comments yes -m Overview.src.html
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  To publish a new compiled version (Overview.html), we need to open this file (Overview.src.html) in any web browser.
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  Once it has loaded we press 'Ctrl + Shift + S' (or 'Cmd' + 'Shift' + 'S' on Mac) and then select
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  'Save as HTML (Source)' from the resulting menu.
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  We then replace Overview.html with the produced HTML source of this process.
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  Next we run HTML5 Tidy over our new Overview.html file with the following command (replacing all = signs with - signs!):
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  @> tidy ==new-blocklevel-tags section ==char-encoding utf8 ==tidy-mark no ==indent yes ==indent-spaces 2 ==indent-attributes yes ==wrap 120 ==hide-comments yes -m Overview.html
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  Now the specification is ready to be published :)
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-->
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<html>
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  <head>
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    <title>
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      Network Service Discovery
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    </title>
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    <meta http-equiv='Content-Type'
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          content='text/html; charset=utf-8'>
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          specStatus:   "ED",
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          //publishDate:  "2013-03-29",
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          shortName:    "discovery-api",
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          edDraftURI:   "http://dvcs.w3.org/hg/dap/raw-file/tip/discovery-api/Overview.html",
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          previousMaturity: "FPWD",
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          previousPublishDate: "2012-10-04",
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          editors: [
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            {
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              name:       "Rich Tibbett",
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              //url:        "http://richt.me/",
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              company:    "Opera Software ASA",
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              companyURL: "http://opera.com/"
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            }
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          ],
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          wg:           "Device APIs Working Group",
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          wgURI:        "http://www.w3.org/2009/dap/",
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          wgPublicList: "public-device-apis",
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  </head>
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  <body>
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    <section id='abstract'>
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      <p>
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        This specification defines a mechanism for an HTML document to discover and subsequently communicate with
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        <abbr title="Hypertext Transfer Protocol">HTTP</abbr>-based services advertised via common discovery protocols
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        within the current network.
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      </p>
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    </section>
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    <section id='sotd'>
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      <p>
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        This document represents the early consensus of the group on the scope and features of the proposed API.
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      </p>
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    </section>
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    <section class="informative">
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      <h3>
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        Introduction
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      </h3>
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      <p>
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        To enable Web pages to connect and communicate with Local-networked Services provided over HTTP, this
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        specification introduces the <a href="#navigatornetworkservice"><code>NavigatorNetworkService</code></a>
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        interface.
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      </p>
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      <p>
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        Using this <abbr title="Application Programming Interface">API</abbr> consists of requesting a well-known
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        service type, known by developers and advertised by Local-networked Devices. User authorization, where the user
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        connects the web page to discovered services, is expected before the web page is able to interact with any
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        Local-networked Services.
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      </p>
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      <p>
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        A web page creates a request to obtain connectivity to services running in the network by specifying a
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        well-known discovery service type that it wishes to interact with.
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      </p>
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      <p>
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        The user agent, having captured all advertised services on the network from the <a>service discovery
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        mechanisms</a> included in this recommendation, attempts to match the requested service type to a discovered
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        service according to the processing described herein.
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      </p>
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      <p>
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        If a service connectivity request is successful then the Web page is provided with a promise-based success
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        callback with the all necessary information to communicate with the authorized Local-networked Service. If the
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        request fails then the Web page will receive a promise-based error callback containing an error string
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        describing the cause of Local-networked Service connectivity failure.
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      </p>
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      <p>
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        Once connected to a Local-networked Service the Web page can send requests and receive responses to the
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        Local-networked Service via the messaging format and appropriate channel inferred from the service type
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        authorized via the provided API. The Web page, once connected, can also receive service-pushed events, in the
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        messaging format supported by the Local-networked Device, if such event subscription functionality is provided
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        by the connected Local-networked Service.
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      </p>
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      <p>
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        Services available within the local network can connect and disconnect at different times during the execution
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        of a web page. The user agent can inform a web page when the state of networked services matching any of the
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        requested valid service types change. Web pages can use this information to enable in-page experiences for
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        communicating the state of networked services with the ability to change the particular service or set of
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        services the page is connected to (by re-invoking the <a href=
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        "#dom-navigator-getnetworkservices"><code>getNetworkServices()</code></a> method defined herein).
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      </p>
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      <div class="example">
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        <p>
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          Example of requesting a DNS-SD advertised service:
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        </p>
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        <hr>
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        <pre class="highlight">
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function showServices( services ) {
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  // Show a list of all the services provided to the web page
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  for(var i = 0, l = services.length; i &lt; l; i++) console.log( services[i].name );
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}
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navigator.getNetworkServices('zeroconf:_boxee-jsonrpc._tcp').then(showServices);
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</pre>
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      </div>
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      <div class="example">
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        <p>
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          Example of requesting a UPnP advertised service, also handling error conditions:
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        </p>
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        <hr>
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        <pre class="highlight">
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function showServices( services ) {
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  // Show a list of all the services provided to the web page
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  for(var i = 0, l = services.length; i &lt; l; i++) console.log( services[i].name );
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}
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function error( e ) {
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  console.log( "Error occurred: " + e.name );
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}
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navigator.getNetworkServices('upnp:urn:schemas-upnp-org:service:ContentDirectory:1').then(showServices, error);
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</pre>
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      </div>
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      <div class="example">
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        <p>
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          Example of requesting either a DNS-SD or UPnP advertised service:
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        </p>
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        <hr>
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        <pre class="highlight">
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function showServices( services ) {
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  // Show a list of all the services provided to the web page (+ service type)
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  for(var i = 0, l = services.length; i &lt; l; i++)
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     console.log( services[i].name + '(' + services[i].type + ')' );
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}
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navigator.getNetworkServices([
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  'zeroconf:_boxee-jsonrpc._tcp',
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  'upnp:urn:schemas-upnp-org:service:ContentDirectory:1'
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]).then(showServices);
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</pre>
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      </div>
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      <p>
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        For more detailed examples, including examples of communicating with obtained networked services, see the
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        <a href="#examples">Examples</a> section.
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      </p>
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    </section>
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    <section id='conformance'>
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      <p>
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        Requirements phrased in the imperative as part of algorithms (such as "strip any leading space characters" or
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        "return false and abort these steps") are to be interpreted with the meaning of the key word ("must", "should",
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        "may", etc) used in introducing the algorithm.
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      </p>
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      <p>
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        Some conformance requirements are phrased as requirements on attributes, methods or objects. Such requirements
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        are to be interpreted as requirements on user agents.
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      </p>
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      <p>
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        Conformance requirements phrased as algorithms or specific steps MAY be implemented in any manner, so long as
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        the end result is equivalent. (In particular, the algorithms defined in this specification are intended to be
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        easy to follow, and not intended to be performant.)
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      </p>
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      <p>
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        The only conformance class defined by this specification is a <dfn>user agent</dfn>.
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      </p>
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      <p>
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        User agents MAY impose implementation-specific limits on otherwise unconstrained inputs, e.g. to prevent denial
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        of service attacks, to guard against running out of memory, or to work around platform-specific limitations.
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      </p>
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      <p>
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        When support for a feature is disabled (e.g. as an emergency measure to mitigate a security problem, or to aid
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        in development, or for performance reasons), user agents MUST act as if they had no support for the feature
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        whatsoever, and as if the feature was not mentioned in this specification. For example, if a particular feature
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        is accessed via an attribute in a Web IDL interface, the attribute itself would be omitted from the objects
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        that implement that interface - leaving the attribute on the object but making it return null or throw an
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        exception is insufficient.
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      </p>
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      <section>
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        <h3>
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          Dependencies
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        </h3>This specification relies on several other underlying specifications.
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        <dl>
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          <dt>
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            HTML
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          </dt>
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          <dd>
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            Many fundamental concepts from HTML are used by this specification. [[!HTML5]]
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          </dd>
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          <dt>
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            WebIDL
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          </dt>
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          <dd>
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            The IDL blocks in this specification use the semantics of the WebIDL specification. [[!WEBIDL]]
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          </dd>
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        </dl>
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      </section>
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    </section>
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    <section>
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      <h3>
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        Terminology
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      </h3>
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      <p>
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        The construction "a <code>Foo</code> object", where <code>Foo</code> is actually an interface, is sometimes
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        used instead of the more accurate "an object implementing the interface <code>Foo</code>".
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      </p>
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      <p>
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        The term DOM is used to refer to the API set made available to scripts in Web applications, and does not
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        necessarily imply the existence of an actual <code>Document</code> object or of any other <code>Node</code>
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        objects as defined in the DOM Core specifications. [[!DOM4]]
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      </p>
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      <p>
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        An IDL attribute is said to be <em>getting</em> when its value is being retrieved (e.g. by author script), and
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        is said to be <em>setting</em> when a new value is assigned to it.
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      </p>
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      <p>
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        A <dfn>valid service type</dfn> is any of the following:
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      </p>
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      <ul>
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        <li>a string that begins with <code>upnp:</code> or <code>zeroconf:</code> followed by one or more characters
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        in the ranges U+0021, U+0023 to U+0027, U+002A to U+002B, U+002D to U+002E, U+0030 to U+0039, U+0041 to U+005A,
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        U+005E to U+007E.
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        </li>
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        <li>a string that begins with <code>dial:</code> followed by an integer version.
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        </li>
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      </ul>
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      <p>
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        A <a>valid service type</a> provided in the <code>type</code> attribute of the <a href=
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        "#dom-navigator-getnetworkservices"><code>getNetworkServices()</code></a> method will be matched against the
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        services currently contained in the <a>list of available service records</a> according to the algorithms
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        defined in this specification.
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      </p>
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      <p>
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        A <dfn>user-agent generated callback url</dfn> is a Local-network accessible URL endpoint that a <a>user
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        agent</a> generates and maintains for receiving HTTP NOTIFY requests from UPnP Event sources. It is only
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        required when the user agent implements UPnP Service Discovery as defined in this specification.
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      </p>
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      <p>
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        In this specification we use the following terms to describe the processes required for Local-networked
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        Services management:
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      </p>
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      <ul>
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        <li>A <dfn>new service</dfn> is a Local-networked Service that has not previously been discovered or registered
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        in the <a>list of available service records</a>.
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        </li>
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        <li>An <dfn>existing service</dfn> is a Local-networked Service that has previously been discovered and is
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        registered in the <a>list of available service records</a>.
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        </li>
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        <li>A <dfn>current service</dfn> is a Local-networked Service, represented by a <a href=
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        "#networkservice"><code>NetworkService</code></a> object, that is currently being shared with a web page via a
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        <a href="#networkservices"><code>NetworkServices</code></a> object registered in the <a>list of active service
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        managers</a>.
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        </li>
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      </ul>
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    </section>
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    <section>
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      <h2>
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        Security and privacy considerations
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      </h2>
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      <p>
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        The API defined in this specification can be used to find and connect to devices and services within a user's
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        current network. This discloses information related to a user's network: devices available on their network and
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        the publicly-accessible services ("networked services") currently running and available on those devices. The
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        distribution of this information could potentially compromise the user's privacy. A conforming implementation
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        of this specification MUST provide a mechanism that protects the user's privacy. This mechanism MUST ensure
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        that no networked service information is retrievable without the user's express permission.
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      </p>
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      <section>
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        <h3>
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          Privacy considerations for API implementations
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        </h3>
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        <p>
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          A <a>user agent</a> MUST NOT provide networked service information to web sites without the express
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          permission of the user. A user agent MUST acquire permission through a user interface, unless they have
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          prearranged trust relationships with users, as described below. The user interface MUST include the document
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          base URL. Those permissions that are acquired through the user interface and that are preserved beyond the
richt@440
   349
          current browsing session (i.e. beyond the time when the browsing context is navigated to another URL) MUST be
richt@440
   350
          revocable and a user agent MUST respect revoked permissions.
richt@440
   351
        </p>
richt@440
   352
        <p>
richt@440
   353
          Obtaining the user's express permission to access one API method does not imply the user has granted
richt@440
   354
          permission for the same web site to access any other methods that may be provided by this API, or to access
richt@440
   355
          the same method with a different set of arguments, as part of the same permission context. If a user has
richt@440
   356
          expressed permission for an implementation to, e.g. find a set of existing networked services, the
richt@440
   357
          implementation MUST seek the user's express permission if and when any subsequent functions are called on
richt@440
   358
          this API.
richt@440
   359
        </p>
richt@440
   360
        <p>
richt@440
   361
          A user agent MAY have prearranged trust relationships that do not require such user interfaces. For example,
richt@440
   362
          while a web browser will present a user interface when a web site performs a networked service lookup, a
richt@440
   363
          different runtime may have a prearranged, delegated security relationship with the user and, as such, a
richt@440
   364
          suitable alternative security and privacy mechanism with which to authorise the retrieval of networked
richt@440
   365
          service information.
richt@440
   366
        </p>
richt@440
   367
      </section>
richt@440
   368
      <section class="informative">
richt@440
   369
        <h3>
richt@440
   370
          Additional API implementation considerations
richt@440
   371
        </h3>
richt@440
   372
        <p>
richt@440
   373
          Further to the requirements listed in the previous section, implementors of the Network Service Discovery API
richt@440
   374
          are also advised to consider the following aspects that can negatively affect the privacy of their users: in
richt@440
   375
          certain cases, users can inadvertently grant permission to the user agent to disclose networked services to
richt@440
   376
          Web sites. In other cases, the content hosted at a certain URL changes in such a way that previously granted
richt@440
   377
          networked service permissions no longer apply as far as the user is concerned. Or the users might simply
richt@440
   378
          change their minds.
richt@440
   379
        </p>
richt@440
   380
        <p>
richt@440
   381
          Predicting or preventing these situations is inherently difficult. Mitigation and in-depth defensive measures
richt@440
   382
          are an implementation responsibility and not prescribed by this specification. However, in designing these
richt@440
   383
          measures, implementers are advised to enable user awareness of networked service sharing, and to provide easy
richt@440
   384
          access to interfaces that enable revocation of permissions that web applications have for accessing networked
richt@440
   385
          services via this API.
richt@440
   386
        </p>
richt@440
   387
      </section>
richt@440
   388
    </section>
richt@440
   389
    <section>
richt@440
   390
      <h2>
richt@239
   391
        Requesting networked services
richt@239
   392
      </h2>
richt@239
   393
      <pre class="widl">
richt@239
   394
[Supplemental, NoInterfaceObject]
richt@180
   395
interface <dfn id="navigatornetworkservice">NavigatorNetworkService</dfn> {
richt@437
   396
  <a class="externalDFN"
richt@437
   397
     href="http://dom.spec.whatwg.org/#promise">Promise</a> <a href=
richt@437
   398
     "#dom-navigator-getnetworkservices">getNetworkServices</a>( in any type );
richt@180
   399
};
richt@447
   400
richt@239
   401
<a class="externalDFN"
richt@239
   402
     href=
richt@239
   403
     "http://www.whatwg.org/specs/web-apps/current-work/complete/timers.html#navigator">Navigator</a> implements <a href=
richt@239
   404
     "#navigatornetworkservice">NavigatorNetworkService</a>;
richt@180
   405
</pre>
richt@239
   406
      <section>
richt@239
   407
        <h2>
richt@239
   408
          Methods
richt@239
   409
        </h2>
richt@239
   410
        <dl class="domintro">
richt@239
   411
          <dt>
richt@437
   412
            <var title="">promise</var> = <var title="">window</var> . <code title="dom-navigator"><a href=
richt@239
   413
            "http://www.whatwg.org/specs/web-apps/current-work/complete/timers.html#navigator">navigator</a></code> .
richt@239
   414
            <code title="dom-navigator-getNetworkServices"><a href=
richt@437
   415
            "#dom-navigator-getnetworkservices">getNetworkServices</a></code> ( <var title="">type</var> )
richt@239
   416
          </dt>
richt@239
   417
          <dd>
richt@239
   418
            <p>
richt@437
   419
              Immediately returns a new <a href="http://dom.spec.whatwg.org/#promise"
richt@437
   420
                 class="externalDFN">Promise</a> object and then the user is prompted to select discovered network
richt@437
   421
                 services that have advertised support for the requested service type(s).
richt@239
   422
            </p>
richt@239
   423
            <p>
richt@239
   424
              The <var title="">type</var> argument contains one or more <a>valid service type</a> tokens that the web
richt@239
   425
              page would like to interact with.
richt@239
   426
            </p>
richt@239
   427
            <p>
richt@437
   428
              If the user accepts, the <var title="">promise</var> object is <a class="externalDFN"
richt@437
   429
                 href="http://dom.spec.whatwg.org/#concept-resolver-resolve">resolved</a>, with a <a href=
richt@437
   430
                 "#networkservices"><code>NetworkServices</code></a> object as its argument.
richt@239
   431
            </p>
richt@239
   432
            <p>
richt@437
   433
              If the user declines, or an error occurs, the <var title="">promise</var> object is <a class=
richt@437
   434
              "externalDFN"
richt@437
   435
                 href="http://dom.spec.whatwg.org/#concept-resolver-reject">rejected</a>.
richt@239
   436
            </p>
richt@239
   437
          </dd>
richt@239
   438
        </dl>
richt@239
   439
        <div>
richt@180
   440
          <p>
richt@239
   441
            When the <dfn id="dom-navigator-getnetworkservices"
richt@437
   442
               title="dom-navigator-getnetworkservices"><code>getNetworkServices(type)</code></dfn> method is called,
richt@437
   443
               the <a>user agent</a> MUST run the following steps:
richt@180
   444
          </p>
richt@180
   445
          <ol class="rule">
richt@437
   446
            <li>Let <var>Network Service Promise</var> be a new <a href="http://dom.spec.whatwg.org/#promise"
richt@437
   447
                  class="externalDFN"><code>Promise</code></a> object.
richt@437
   448
            </li>
richt@437
   449
            <li>Let <var>Network Service Promise's Resolver</var> be the default <a href=
richt@437
   450
            "http://dom.spec.whatwg.org/#concept-resolver"
richt@437
   451
                  class="externalDFN">resolver</a> of <var>Network Service Promise</var>.
richt@437
   452
            </li>
richt@437
   453
            <li>Return <var>Network Service Promise</var>, and run the remaining steps asynchronously.
richt@437
   454
            </li>
richt@239
   455
            <li>Let <var>requested control types</var> be initially set to an empty array.
richt@239
   456
            </li>
richt@239
   457
            <li>If <var>type</var> is an array consisting of one or more <a>valid service type</a> tokens, then let
richt@239
   458
            <var>requested control types</var> by the value of <var>type</var>, removing any non-<a>valid service
richt@239
   459
            type</a> tokens from the resulting array.
richt@239
   460
            </li>
richt@239
   461
            <li>If <var>type</var> is a string consisting of one <a>valid service type</a> token, then let
richt@239
   462
            <var>requested control types</var> be an array containing one item with a value of <var>type</var>.
richt@239
   463
            </li>
richt@239
   464
            <li>If <var>requested control types</var> is an array that contains at least one or more <a title=
richt@239
   465
            "valid service type">valid service type</a> tokens then continue to the step labeled <em>process</em>
richt@437
   466
            below. Otherwise, reject <var>Network Service Promise</var> by running the <a href=
richt@437
   467
            "http://dom.spec.whatwg.org/#concept-resolver-reject"
richt@437
   468
                  class="externalDFN">resolver reject algorithm</a> against the <var>Network Service Promise's
richt@447
   469
                  Resolver</var>, passing in a newly constructed <a href="http://dom.spec.whatwg.org/#domerror"
richt@447
   470
                  class="externalDFN"><code>DOMError</code></a> object whose <code>name</code> attribute has the string
richt@447
   471
                  value "UnknownTypePrefixError" (<a href=
richt@447
   472
                  "#dom-domerror-extensions-unknown_type_prefix"><code>UNKNOWN_TYPE_PREFIX_ERR</code></a>) and whose
richt@447
   473
                  <code>message</code> attribute has a helpful implementation-dependent message that explains this
richt@447
   474
                  error, abort any remaining steps and return.
richt@239
   475
            </li>
richt@180
   476
            <li>
richt@239
   477
              <em>Process</em>: Let <var>services found</var> be an empty array.
richt@180
   478
            </li>
richt@239
   479
            <li>For each <var>available service</var> in the <a>list of available service records</a> run the following
richt@239
   480
            steps:
richt@239
   481
              <ol class="rule">
richt@239
   482
                <li>For each <var>requested control type</var> in <var>requested control types</var>: If <var>available
richt@239
   483
                service</var>'s <code>type</code> attribute equals the <var>requested control type</var> then let <var>
richt@239
   484
                  matched service</var> equal the value of <var>available service</var> and continue at the step
richt@239
   485
                  labeled <var>attach</var> below.
richt@239
   486
                </li>
richt@239
   487
                <li>Continue at the next <var>available service</var>.
richt@239
   488
                </li>
richt@239
   489
                <li>
richt@239
   490
                  <em>Attach</em>: If <var>matched service</var> is not empty then run the following steps:
richt@239
   491
                  <ol class="rule">
richt@239
   492
                    <li>Let <var>new service object</var> be a new <a href=
richt@239
   493
                    "#networkservice"><code>NetworkService</code></a> object, mapping the parameters of <var>matched
richt@239
   494
                    service</var> to this new object where possible.
richt@239
   495
                    </li>
richt@239
   496
                    <li>Append <var>new service object</var> to the <var>services found</var> array.
richt@239
   497
                    </li>
richt@239
   498
                  </ol>
richt@239
   499
                </li>
richt@239
   500
              </ol>
richt@180
   501
            </li>
richt@239
   502
            <li>Optionally, e.g. based on a previously-established user preference, for security reasons, or due to
richt@437
   503
            platform limitations, the <a>user agent</a> MAY reject <var>Network Service Promise</var> by running the
richt@437
   504
            <a href="http://dom.spec.whatwg.org/#concept-resolver-reject"
richt@437
   505
                  class="externalDFN">resolver reject algorithm</a> against the <var>Network Service Promise's
richt@447
   506
                  Resolver</var>, passing in a newly constructed <a href="http://dom.spec.whatwg.org/#domerror"
richt@447
   507
                  class="externalDFN"><code>DOMError</code></a> object whose <code>name</code> attribute has the string
richt@447
   508
                  value "PermissionDeniedError" (<a href=
richt@447
   509
                  "#dom-domerror-extensions-permission_denied"><code>PERMISSION_DENIED_ERR</code></a>) and whose
richt@447
   510
                  <code>message</code> attribute has a helpful implementation-dependent message that explains this
richt@447
   511
                  error, abort any remaining steps and return.
richt@180
   512
            </li>
richt@371
   513
            <li>The user agent MUST NOT provide the entry script's origin with a <a href=
richt@371
   514
            "#networkservices"><code>NetworkServices</code></a> object without prior permission given by the user.
richt@239
   515
              <p>
richt@371
   516
                If <var>services found</var> is not an empty array then the <a>user agent</a> MAY choose to prompt the
richt@371
   517
                user in a user-agent-specific manner for permission to provide the <a href=
richt@371
   518
                "http://www.whatwg.org/specs/web-apps/current-work/complete/browsers.html#entry-script"
richt@371
   519
                   class="externalDFN">entry script</a>'s <a href=
richt@371
   520
                   "http://www.whatwg.org/specs/web-apps/current-work/complete/origin-0.html#origin"
richt@371
   521
                   class="externalDFN">origin</a> with a <a href="#networkservices"><code>NetworkServices</code></a>
richt@371
   522
                   object representing the <a>user-authorized</a> subset of <var>services found</var>.
richt@180
   523
              </p>
richt@239
   524
              <p>
richt@437
   525
                Alternatively, the user agent MAY wish to skip this user opt-in step and choose to fulfill <var>Network
richt@437
   526
                Service Promise</var> immediately based on a previously-established user preference, for security
richt@437
   527
                reasons, or due to platform limitations. In such an implementation, if <var>Network Service
richt@437
   528
                Promise</var> is to be fulfilled as a result of a previously-established user preference then the
richt@437
   529
                <a>user agent</a> MUST continue at the next step of this algorithm.
richt@371
   530
              </p>
richt@371
   531
              <p>
richt@371
   532
                If permission has been granted by the user to access one or more networked services then the <a>user
richt@371
   533
                agent</a> SHOULD include an "ongoing local-network communication" indicator.
richt@371
   534
              </p>
richt@371
   535
              <p>
richt@371
   536
                If permission has been denied by the user, <a>user agent</a> or platform, then the <a>user agent</a>
richt@437
   537
                MUST reject <var>Network Service Promise</var> by running the <a href=
richt@437
   538
                "http://dom.spec.whatwg.org/#concept-resolver-reject"
richt@437
   539
                   class="externalDFN">resolver reject algorithm</a> against the <var>Network Service Promise's
richt@447
   540
                   Resolver</var>, passing in a newly constructed <a href="http://dom.spec.whatwg.org/#domerror"
richt@447
   541
                   class="externalDFN"><code>DOMError</code></a> object whose <code>name</code> attribute has the
richt@447
   542
                   string value "PermissionDeniedError" (<a href=
richt@447
   543
                   "#dom-domerror-extensions-permission_denied"><code>PERMISSION_DENIED_ERR</code></a>) and whose
richt@447
   544
                   <code>message</code> attribute has a helpful implementation-dependent message that explains this
richt@447
   545
                   error, abort any remaining steps and return.
richt@239
   546
              </p>
richt@180
   547
              <p>
richt@371
   548
                If the user never responds or no previously-established user preference has been met, this algorithm
richt@371
   549
                stalls on this step.
richt@180
   550
              </p>
richt@180
   551
            </li>
richt@254
   552
            <li>Let <var>services</var> be an empty array.
richt@180
   553
            </li>
richt@371
   554
            <li>If <var>services found</var> is not an empty array then set <var>services</var> to be an array of one
richt@371
   555
            or more <a href="#networkservice"><code>NetworkService</code></a> objects for which the user granted
richt@371
   556
            permission above - known as the current objects <dfn>user-authorized</dfn> services.
richt@254
   557
            </li>
richt@377
   558
            <li>Remove all previously whitelisted urls from the <a>entry script origin's URL whitelist</a> granted in
richt@377
   559
            the current <a href="http://www.whatwg.org/specs/web-apps/current-work/complete/browsers.html#entry-script"
richt@377
   560
                  class="externalDFN">entry script</a>'s <a href=
richt@377
   561
                  "http://www.whatwg.org/specs/web-apps/current-work/complete/origin-0.html#origin"
richt@377
   562
                  class="externalDFN">origin</a>.
richt@377
   563
            </li>
richt@254
   564
            <li>For each Object <var>service</var> in <var>services</var>, if any, run the following sub-steps:
richt@239
   565
              <ol class="rule">
richt@239
   566
                <li>Add the <var>service</var>'s <code>url</code> parameter to the <a>entry script origin's
richt@239
   567
                  <abbr title="Uniform Resource Locator">URL</abbr> whitelist</a>.
richt@239
   568
                </li>
richt@239
   569
                <li>If <var>service</var>'s <code>type</code> parameter begins with the DOMString "<code>upnp:</code>"
richt@239
   570
                and the <var>service</var>'s <code>eventsUrl</code> parameter is not empty then <a>setup a UPnP Events
richt@239
   571
                Subscription</a> for <var>service</var>.
richt@239
   572
                </li>
richt@239
   573
              </ol>
richt@180
   574
            </li>
richt@239
   575
            <li>Let <var>services manager</var> be a new <a href="#networkservices"><code>NetworkServices</code></a>
richt@239
   576
            object.
richt@180
   577
            </li>
richt@375
   578
            <li>Store <var>requested control types</var> against <var>services manager</var> as an internal variable.
richt@375
   579
            </li>
richt@239
   580
            <li>Set <var>services manager</var>'s <a href=
richt@239
   581
            "#dom-networkservices-servicesavailable"><code>servicesAvailable</code></a> attribute to the number of
richt@250
   582
            items currently found in the <a>list of available service records</a> whose <code>type</code> property
richt@239
   583
            matches any of the tokens requested in <var>requested control types</var>.
richt@180
   584
            </li>
richt@371
   585
            <li>Add <var>services</var>, if any, to the <var>services manager</var> object as its collection of
richt@371
   586
            <a>indexed properties</a>. If <var>services</var> is an empty array then the <var>services manager</var>
richt@371
   587
            does not have any <var>indexed properties</var>.
richt@250
   588
            </li>
richt@250
   589
            <li>Set <var>services manager</var>'s <a href="#dom-networkservices-length"><code>length</code></a>
richt@250
   590
            attribute to the number of items in <var>services</var>.
richt@250
   591
            </li>
richt@250
   592
            <li>Add <var>services manager</var> to the <a>list of active service managers</a>.
richt@180
   593
            </li>
richt@437
   594
            <li>The <a>user agent</a> MUST fulfill <var>Network Service Promise</var> by running the <a href=
richt@437
   595
            "http://dom.spec.whatwg.org/#concept-resolver-fulfill"
richt@437
   596
                  class="externalDFN">resolver fulfill algorithm</a> against the <var>Network Service Promise's
richt@437
   597
                  Resolver</var>, passing in <var>services manager</var> as its argument.
richt@180
   598
            </li>
richt@180
   599
          </ol>
richt@180
   600
          <p>
richt@239
   601
            The <a href="http://www.whatwg.org/specs/web-apps/current-work/complete/webappapis.html#task-source"
richt@239
   602
               class="externalDFN">task source</a> for these <a href=
richt@239
   603
               "http://www.whatwg.org/specs/web-apps/current-work/complete/webappapis.html#concept-task"
richt@239
   604
               class="externalDFN">tasks</a> is the <a href=
richt@239
   605
               "http://www.whatwg.org/specs/web-apps/current-work/complete/webappapis.html#user-interaction-task-source"
richt@239
   606
               class="externalDFN">user interaction task source</a>.
richt@180
   607
          </p>
richt@180
   608
          <p>
richt@239
   609
            When a <a href="#networkservice"><code>NetworkService</code></a> object is provided to a Web page, the
richt@441
   610
            <a>user agent</a> MUST add its <a href="#dom-networkservice-url"><code>url</code></a> to the <dfn>entry
richt@441
   611
            script origin's URL whitelist</dfn>. This list enables the Web page to override and initiate cross-site
richt@441
   612
            resource requests towards these URLs, and any sub-resources of these URLs, within the current <a href=
richt@239
   613
            "http://www.whatwg.org/specs/web-apps/current-work/complete/browsers.html#entry-script"
richt@239
   614
               class="externalDFN">entry script</a>'s <a href=
richt@239
   615
               "http://www.whatwg.org/specs/web-apps/current-work/complete/origin-0.html#origin"
richt@239
   616
               class="externalDFN">origin</a> via various existing mechanisms (e.g. Web Sockets, Server-Sent Events,
richt@239
   617
               Web Messaging, XMLHttpRequest).
richt@239
   618
          </p>
richt@180
   619
          <p>
richt@371
   620
            If the user navigates away from the <a href=
richt@371
   621
            "http://www.whatwg.org/specs/web-apps/current-work/complete/browsers.html#entry-script"
richt@371
   622
               class="externalDFN">entry script</a>'s <a href=
richt@371
   623
               "http://www.whatwg.org/specs/web-apps/current-work/complete/origin-0.html#origin"
richt@441
   624
               class="externalDFN">origin</a> or permission to access a given networked service is revoked at any time
richt@441
   625
               by the platform or user then the <a>user agent</a> <em class="ct">MUST</em> remove its previously
richt@441
   626
               whitelisted urls from the <a>entry script origin's URL whitelist</a>.
richt@441
   627
          </p>
richt@441
   628
          <p>
richt@441
   629
            There is no implied persistence to networked service sharing provided to a web page. It MUST NOT be
richt@441
   630
            possible to access a previously white-listed networked service without user authorization in all of the
richt@441
   631
            following cases:
richt@180
   632
          </p>
richt@239
   633
          <ul>
richt@239
   634
            <li>If the current script is reloaded at any point in the same or different window.
richt@239
   635
            </li>
richt@239
   636
            <li>if the current script reinvokes the <a href=
richt@239
   637
            "#dom-navigator-getnetworkservices"><code>getNetworkServices()</code></a> method at any point in its
richt@239
   638
            execution.
richt@239
   639
            </li>
richt@239
   640
            <li>If the user navigates forward or back in their history to reload the current page.
richt@239
   641
            </li>
richt@239
   642
            <li>If a script is running in a different origin.
richt@239
   643
            </li>
richt@239
   644
          </ul>
richt@239
   645
        </div>
richt@180
   646
      </section>
richt@180
   647
      <section>
richt@239
   648
        <h3>
richt@239
   649
          Error Handling
richt@239
   650
        </h3>
richt@239
   651
        <dl class="domintro">
richt@239
   652
          <dt>
richt@447
   653
            <var title="">error</var> . <code title="dom-NavigatorNetworkServiceError-name"><a href=
richt@447
   654
            "#dom-domerror-extensions-name">name</a></code>
richt@239
   655
          </dt>
richt@239
   656
          <dd>
richt@239
   657
            <p>
richt@447
   658
              Returns the current error's error name. At the current time, this will be "PermissionDeniedError" or
richt@447
   659
              "UnknownTypePrefixError", for which the corresponding error constants <a href=
richt@447
   660
              "#dom-domerror-extensions-permission_denied"><code>PERMISSION_DENIED_ERR</code></a> and <a href=
richt@447
   661
              "#dom-domerror-extensions-unknown_type_prefix"><code>UNKNOWN_TYPE_PREFIX_ERR</code></a> are defined.
richt@239
   662
            </p>
richt@239
   663
          </dd>
richt@239
   664
        </dl>
richt@239
   665
        <p>
richt@447
   666
          The <dfn id="dom-domerror-extensions-name"
richt@447
   667
             title="dom-domerror-extensions-name"><code>name</code></dfn> attribute of a <a href=
richt@447
   668
             "http://dom.spec.whatwg.org/#domerror"
richt@447
   669
             class="externalDFN"><code>DOMError</code></a> object returned from this API <em class="ct">MUST</em>
richt@447
   670
             return the name for the error, which will be one of the following:
richt@239
   671
        </p>
richt@239
   672
        <dl>
richt@239
   673
          <dt>
richt@447
   674
            <dfn id="dom-domerror-extensions-permission_denied"
richt@447
   675
                title="dom-domerror-extensions-permission_denied"><code>PERMISSION_DENIED_ERR</code></dfn> (DOMString
richt@447
   676
                value "PermissionDeniedError")
richt@239
   677
          </dt>
richt@239
   678
          <dd>
richt@239
   679
            The user or user agent denied the page permission to access any services.
richt@239
   680
          </dd>
richt@239
   681
          <dt>
richt@447
   682
            <dfn id="dom-domerror-extensions-unknown_type_prefix"
richt@447
   683
                title="dom-domerror-extensions-unknown_type_prefix"><code>UNKNOWN_TYPE_PREFIX_ERR</code></dfn>
richt@447
   684
                (DOMString value "UnknownTypePrefixError")
richt@239
   685
          </dt>
richt@239
   686
          <dd>
richt@239
   687
            No <a>valid service type</a> tokens were provided in the method invocation.
richt@239
   688
          </dd>
richt@239
   689
        </dl>
richt@239
   690
      </section>
richt@239
   691
    </section>
richt@239
   692
    <section>
richt@239
   693
      <h2>
richt@239
   694
        Obtaining networked services
richt@239
   695
      </h2>
richt@180
   696
      <p>
richt@371
   697
        The <a href="#networkservices"><code>NetworkServices</code></a> interface represents a collection of zero or
richt@371
   698
        more <dfn>indexed properties</dfn> that are each a <a>user-authorized</a> <a href=
richt@371
   699
        "#networkservice"><code>NetworkService</code></a> object.
richt@254
   700
      </p>
richt@254
   701
      <p>
richt@437
   702
        A <a href="#networkservices"><code>NetworkServices</code></a> object is the <a href=
richt@437
   703
        "http://dom.spec.whatwg.org/#concept-promise-result"
richt@437
   704
           class="externalDFN">promise result</a> from a call to <a href=
richt@437
   705
           "#dom-navigator-getnetworkservices"><code>getNetworkServices()</code></a>.
richt@180
   706
      </p>
richt@239
   707
      <pre class="widl">
richt@180
   708
[NoInterfaceObject]
richt@180
   709
interface <dfn id="networkservices">NetworkServices</dfn> {
richt@180
   710
  readonly attribute unsigned long    <a href="#dom-networkservices-length">length</a>;
richt@180
   711
  getter <a href="#networkservice">NetworkService</a> (unsigned long index);
richt@239
   712
  <a href="#networkservice">NetworkService</a>? <a href=
richt@239
   713
"#dom-networkservices-getservicebyid">getServiceById</a>(DOMString id);
richt@180
   714
richt@180
   715
  readonly attribute unsigned long    <a href="#dom-networkservices-servicesavailable">servicesAvailable</a>;
richt@180
   716
richt@180
   717
  // event handler attributes
richt@239
   718
           attribute <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/webappapis.html#eventhandler"
richt@239
   719
     class="externalDFN">EventHandler</a>     <a href="#dom-networkservices-onserviceavailable">onserviceavailable</a>;
richt@239
   720
           attribute <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/webappapis.html#eventhandler"
richt@239
   721
     class="externalDFN">EventHandler</a>     <a href=
richt@239
   722
     "#dom-networkservices-onserviceunavailable">onserviceunavailable</a>;
richt@180
   723
richt@180
   724
};
richt@180
   725
richt@239
   726
<a href="#networkservices">NetworkServices</a> implements <a href=
richt@239
   727
"http://dvcs.w3.org/hg/domcore/raw-file/tip/Overview.html#interface-eventtarget"
richt@239
   728
     class="externalDFN">EventTarget</a>;
richt@180
   729
</pre>
richt@180
   730
      <section>
richt@239
   731
        <h2>
richt@239
   732
          Attributes
richt@239
   733
        </h2>
richt@180
   734
        <dl class="domintro">
richt@180
   735
          <dt>
richt@239
   736
            <code title="dom-networkservices-length"><a href="#dom-networkservices-length">length</a></code>
richt@180
   737
          </dt>
richt@180
   738
          <dd>
richt@180
   739
            <p>
richt@398
   740
              Returns the current number of <a>indexed properties</a> in the current object's collection.
richt@180
   741
            </p>
richt@180
   742
          </dd>
richt@180
   743
          <dt>
richt@239
   744
            <code title="dom-networkservices-servicesavailable"><a href=
richt@239
   745
            "#dom-networkservices-servicesavailable">servicesAvailable</a></code>
richt@180
   746
          </dt>
richt@180
   747
          <dd>
richt@180
   748
            <p>
richt@250
   749
              Returns the current number of items matching one of the app-requested <a>valid service type</a> tokens in
richt@250
   750
              the <a>list of available service records</a>.
richt@180
   751
            </p>
richt@180
   752
          </dd>
richt@180
   753
        </dl>
richt@180
   754
        <div>
richt@239
   755
          <p>
richt@250
   756
            The <dfn id="dom-networkservices-length"><code>length</code></dfn> attribute MUST return the number of
richt@250
   757
            <a href="#networkservice"><code>NetworkService</code></a> objects represented by the collection.
richt@239
   758
          </p>
richt@239
   759
          <p>
richt@250
   760
            The <dfn id="dom-networkservices-servicesavailable"><code>servicesAvailable</code></dfn> attribute MUST
richt@250
   761
            return the number of services in the <a>list of available service records</a> whose <code>type</code>
richt@437
   762
            attribute matches any of the <a>valid service type</a> tokens that were initially used to create the
richt@437
   763
            current <a href="#networkservices"><code>NetworkServices</code></a> object.
richt@239
   764
          </p>
richt@180
   765
        </div>
richt@180
   766
      </section>
richt@180
   767
      <section>
richt@239
   768
        <h2>
richt@239
   769
          Methods
richt@239
   770
        </h2>
richt@180
   771
        <dl class="domintro">
richt@239
   772
          <dt>
richt@239
   773
            <code title="networkservices-getter"><a href="#networkservices">services</a></code> [ <var title=
richt@239
   774
            "">index</var> ]
richt@239
   775
          </dt>
richt@239
   776
          <dd>
richt@239
   777
            <p>
richt@239
   778
              Returns the specified <a href="#networkservice"><code>NetworkService</code></a> object.
richt@239
   779
            </p>
richt@239
   780
          </dd>
richt@239
   781
          <dt>
richt@239
   782
            <code title="networkservices-getter"><a href="#networkservices">services</a></code> . <code title=
richt@239
   783
            "dom-networkservices-getservicebyid"><a href=
richt@239
   784
            "#dom-networkservices-getservicebyid">getServiceById</a></code> ( <var title="">id</var> )
richt@239
   785
          </dt>
richt@239
   786
          <dd>
richt@239
   787
            <p>
richt@239
   788
              Returns the <a href="#networkservice"><code>NetworkService</code></a> object with the given identifier,
richt@239
   789
              or null if no service has that identifier.
richt@239
   790
            </p>
richt@239
   791
          </dd>
richt@239
   792
        </dl>
richt@239
   793
        <p>
richt@371
   794
          A <a href="#networkservices"><code>NetworkServices</code></a> object represents the current collection of
richt@371
   795
          zero or more <a href="#networkservice"><code>NetworkService</code></a> objects - its <a>indexed
richt@388
   796
          properties</a>. The <a>indexed properties</a> of a <a href=
richt@388
   797
          "#networkservices"><code>NetworkServices</code></a> object are <span>immutable</span> meaning that <a>indexed
richt@388
   798
          properties</a> cannot be added and <a>indexed properties</a> cannot be removed for the lifetime of a <a href=
richt@388
   799
          "#networkservices"><code>NetworkServices</code></a> object.
richt@239
   800
        </p>
richt@239
   801
        <p>
richt@239
   802
          The <a href=
richt@239
   803
          "http://www.whatwg.org/specs/web-apps/current-work/multipage/infrastructure.html#supported-property-indices"
richt@239
   804
             class="externalDFN">supported property indices</a> of <a href=
richt@239
   805
             "#networkservices"><code>NetworkServices</code></a> objects at any instant are the numbers from zero to
richt@250
   806
             the number of the <a href="#networkservice"><code>NetworkService</code></a> objects in the collection
richt@250
   807
             minus one.
richt@239
   808
        </p>
richt@398
   809
        <p class="note">
richt@398
   810
          Each service in a <a href="#networkservices"><code>NetworkServices</code></a> object thus has an index; the
richt@398
   811
          first has the index 0, and each subsequent service is numbered one higher than the previous one.
richt@398
   812
        </p>
richt@239
   813
        <p>
richt@239
   814
          To <a href=
richt@239
   815
          "http://www.whatwg.org/specs/web-apps/current-work/multipage/infrastructure.html#determine-the-value-of-an-indexed-property"
richt@239
   816
             class="externalDFN">determine the value of an indexed property</a> for a given index <var>index</var> in a
richt@250
   817
             <a href="#networkservices"><code>NetworkServices</code></a> object the user agent MUST return the <a href=
richt@250
   818
             "#networkservice"><code>NetworkService</code></a> object that represents the <var>index</var>th item in
richt@250
   819
             the collection.
richt@239
   820
        </p>
richt@239
   821
        <p>
richt@239
   822
          The <dfn id="dom-networkservices-getservicebyid"><code>getServiceById(id)</code></dfn> method <em class=
richt@239
   823
          "ct">MUST</em> return the first <a href="#networkservice"><code>NetworkService</code></a> object in the
richt@250
   824
          collection whose <a href="#dom-networkservice-id"><code>id</code></a> attribute is equal to the value of the
richt@250
   825
          <var>id</var> argument provided. When no <a href="#networkservice"><code>NetworkService</code></a> objects
richt@250
   826
          match the given argument, the method MUST return null.
richt@239
   827
        </p>
richt@180
   828
      </section>
richt@180
   829
      <section>
richt@239
   830
        <h2>
richt@239
   831
          Events
richt@239
   832
        </h2>
richt@239
   833
        <p>
richt@239
   834
          The following are the event handlers (and their corresponding event handler event types) that <em class=
richt@239
   835
          "ct">MUST</em> be supported, as IDL attributes, by all objects implementing the <a href=
richt@239
   836
          "#networkservices"><code>NetworkServices</code></a> interface:
richt@239
   837
        </p>
richt@243
   838
        <table border="1">
richt@239
   839
          <thead>
richt@239
   840
            <tr>
richt@239
   841
              <th>
richt@239
   842
                <span title="event handlers">Event handler</span>
richt@239
   843
              </th>
richt@239
   844
              <th>
richt@239
   845
                <span>Event handler event type</span>
richt@239
   846
              </th>
richt@239
   847
            </tr>
richt@239
   848
          </thead>
richt@239
   849
          <tbody>
richt@239
   850
            <tr>
richt@239
   851
              <td>
richt@239
   852
                <dfn id="dom-networkservices-onserviceavailable"
richt@239
   853
                    title="dom-NetworkServices-onserviceavailable"><code>onserviceavailable</code></dfn>
richt@239
   854
              </td>
richt@239
   855
              <td>
richt@239
   856
                <a href="#event-serviceavailable"><code>serviceavailable</code></a>
richt@239
   857
              </td>
richt@239
   858
            </tr>
richt@239
   859
            <tr>
richt@239
   860
              <td>
richt@239
   861
                <dfn id="dom-networkservices-onserviceunavailable"
richt@239
   862
                    title="dom-NetworkServices-onserviceunavailable"><code>onserviceunavailable</code></dfn>
richt@239
   863
              </td>
richt@239
   864
              <td>
richt@239
   865
                <a href="#event-serviceunavailable"><code>serviceunavailable</code></a>
richt@239
   866
              </td>
richt@239
   867
            </tr>
richt@239
   868
          </tbody>
richt@239
   869
        </table>
richt@180
   870
      </section>
richt@180
   871
    </section>
richt@180
   872
    <section>
richt@239
   873
      <h2>
richt@239
   874
        Communicating with a networked service
richt@239
   875
      </h2>
richt@239
   876
      <p>
richt@239
   877
        The <a href="#networkservice"><code>NetworkService</code></a> interface is used to provide a set of connection
richt@239
   878
        information for an HTTP service endpoint and if available, service events, running on a networked device.
richt@239
   879
      </p>
richt@239
   880
      <pre class="widl">
richt@180
   881
[NoInterfaceObject]
richt@180
   882
interface <dfn id="networkservice">NetworkService</dfn> {
richt@180
   883
  readonly attribute DOMString        <a href="#dom-networkservice-id">id</a>;
richt@180
   884
  readonly attribute DOMString        <a href="#dom-networkservice-name">name</a>;
richt@180
   885
  readonly attribute DOMString        <a href="#dom-networkservice-type">type</a>;
richt@180
   886
  readonly attribute DOMString        <a href="#dom-networkservice-url">url</a>;
richt@180
   887
  readonly attribute DOMString        <a href="#dom-networkservice-config">config</a>;
richt@180
   888
richt@191
   889
  readonly attribute boolean          <a href="#dom-networkservice-online">online</a>;
richt@180
   890
richt@180
   891
  // event handler attributes
richt@239
   892
           attribute <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/webappapis.html#eventhandler"
richt@239
   893
     class="externalDFN">EventHandler</a>     <a href="#dom-networkservice-onserviceonline">onserviceonline</a>;
richt@239
   894
           attribute <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/webappapis.html#eventhandler"
richt@239
   895
     class="externalDFN">EventHandler</a>     <a href="#dom-networkservice-onserviceoffline">onserviceoffline</a>;
richt@191
   896
richt@239
   897
           attribute <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/webappapis.html#eventhandler"
richt@239
   898
     class="externalDFN">EventHandler</a>     <a href="#dom-networkservice-onnotify">onnotify</a>;
richt@180
   899
};
richt@180
   900
richt@239
   901
<a href="#networkservice">NetworkService</a> implements <a href=
richt@239
   902
"http://dvcs.w3.org/hg/domcore/raw-file/tip/Overview.html#interface-eventtarget"
richt@239
   903
     class="externalDFN">EventTarget</a>;
richt@180
   904
</pre>
richt@239
   905
      <section>
richt@239
   906
        <h2>
richt@239
   907
          Attributes
richt@239
   908
        </h2>
richt@239
   909
        <dl class="domintro">
richt@239
   910
          <dt>
richt@239
   911
            <var title="">service</var> . <code title="dom-networkservice-id"><a href=
richt@239
   912
            "#dom-networkservice-id">id</a></code>
richt@239
   913
          </dt>
richt@239
   914
          <dd>
richt@239
   915
            <p>
richt@239
   916
              A unique identifier for the given user-selected service instance.
richt@239
   917
            </p>
richt@239
   918
          </dd>
richt@239
   919
          <dt>
richt@239
   920
            <var title="">service</var> . <code title="dom-networkservice-name"><a href=
richt@239
   921
            "#dom-networkservice-name">name</a></code>
richt@239
   922
          </dt>
richt@239
   923
          <dd>
richt@239
   924
            <p>
richt@239
   925
              The name of the user-selected service.
richt@239
   926
            </p>
richt@239
   927
          </dd>
richt@239
   928
          <dt>
richt@239
   929
            <var title="">service</var> . <code title="dom-networkservice-type"><a href=
richt@239
   930
            "#dom-networkservice-type">type</a></code>
richt@239
   931
          </dt>
richt@239
   932
          <dd>
richt@239
   933
            <p>
richt@239
   934
              The <a>valid service type</a> token value of the user-selected service.
richt@239
   935
            </p>
richt@239
   936
          </dd>
richt@239
   937
          <dt>
richt@239
   938
            <var title="">service</var> . <code title="dom-networkservice-url"><a href=
richt@239
   939
            "#dom-networkservice-url">url</a></code>
richt@239
   940
          </dt>
richt@239
   941
          <dd>
richt@239
   942
            <p>
richt@239
   943
              The control URL endpoint (including any required port information) of the user-selected control service
richt@239
   944
              that has been added to the <a>entry script origin's URL whitelist</a>.
richt@239
   945
            </p>
richt@239
   946
          </dd>
richt@239
   947
          <dt>
richt@239
   948
            <var title="">service</var> . <code title="dom-networkservice-config"><a href=
richt@239
   949
            "#dom-networkservice-config">config</a></code>
richt@239
   950
          </dt>
richt@239
   951
          <dd>
richt@239
   952
            <p>
richt@239
   953
              The configuration information associated with the service depending on the requested service type.
richt@239
   954
            </p>
richt@239
   955
          </dd>
richt@239
   956
        </dl>
richt@239
   957
        <p>
richt@239
   958
          The <dfn id="dom-networkservice-id"><code>id</code></dfn> attribute is a unique identifier for the service.
richt@250
   959
          The same service provided at different times or on different objects MUST have the same <a href=
richt@250
   960
          "#dom-networkservice-id"><code>id</code></a> value.
richt@239
   961
        </p>
richt@239
   962
        <p>
richt@239
   963
          The <dfn id="dom-networkservice-name"><code>name</code></dfn> attribute represents a human-readable title for
richt@239
   964
          the service.
richt@239
   965
        </p>
richt@239
   966
        <p>
richt@239
   967
          The <dfn id="dom-networkservice-type"><code>type</code></dfn> attribute reflects the value of the <a>valid
richt@239
   968
          service type</a> of the service.
richt@239
   969
        </p>
richt@239
   970
        <p>
richt@239
   971
          The <dfn id="dom-networkservice-url"><code>url</code></dfn> attribute is an <a href=
richt@239
   972
          "http://www.w3.org/TR/html5/urls.html#absolute-url"
richt@239
   973
             class="externalDFN">absolute URL</a> pointing to the root HTTP endpoint for the service that has been
richt@239
   974
             added to the <a>entry script origin's URL whitelist</a>. Web pages can subsequently use this value for
richt@239
   975
             implicit cross-document messaging via various existing mechanisms (e.g. Web Sockets, Server-Sent Events,
richt@239
   976
             Web Messaging, XMLHttpRequest).
richt@239
   977
        </p>
richt@239
   978
        <p>
richt@239
   979
          The <dfn id="dom-networkservice-config"><code>config</code></dfn> attribute provides the raw configuration
richt@239
   980
          information extracted from the given network service.
richt@239
   981
        </p>
richt@239
   982
      </section>
richt@239
   983
      <section>
richt@239
   984
        <h3>
richt@239
   985
          States
richt@239
   986
        </h3>
richt@239
   987
        <dl class="domintro">
richt@239
   988
          <dt>
richt@239
   989
            <var title="">service</var> . <code title="dom-networkservice-online"><a href=
richt@239
   990
            "#dom-networkservice-online">online</a></code>
richt@239
   991
          </dt>
richt@239
   992
          <dd>
richt@239
   993
            <p>
richt@239
   994
              Returns <code>true</code> if the service is reporting that it is accessible on the local network or
richt@390
   995
              <code>false</code> if the service is no longer accessible (temporarily or permanently) on the local
richt@390
   996
              network.
richt@239
   997
            </p>
richt@239
   998
          </dd>
richt@239
   999
        </dl>
richt@239
  1000
        <p>
richt@239
  1001
          The <dfn id="dom-networkservice-online"><code>online</code></dfn> attribute indicates whether the service is
richt@390
  1002
          either <var>online</var>, and therefore accessible on the local network, in which case this attribute will
richt@390
  1003
          return <code>true</code> or, <var>offline</var>, and therefore not accessible on the local network, either
richt@390
  1004
          temporarily or permanently, in which case this attribute will return <code>false</code>. This attribute MUST
richt@390
  1005
          default to <code>true</code>.
richt@239
  1006
        </p>
richt@239
  1007
      </section>
richt@239
  1008
      <section>
richt@239
  1009
        <h3>
richt@239
  1010
          Events
richt@239
  1011
        </h3>
richt@239
  1012
        <p>
richt@239
  1013
          The following are the event handlers (and their corresponding event handler event types) that <em class=
richt@239
  1014
          "ct">MUST</em> be supported, as IDL attributes, by all objects implementing the <a href=
richt@239
  1015
          "#networkservice"><code>NetworkService</code></a> interface:
richt@239
  1016
        </p>
richt@243
  1017
        <table border="1">
richt@239
  1018
          <thead>
richt@239
  1019
            <tr>
richt@239
  1020
              <th>
richt@239
  1021
                <span title="event handlers">Event handler</span>
richt@239
  1022
              </th>
richt@239
  1023
              <th>
richt@239
  1024
                <span>Event handler event type</span>
richt@239
  1025
              </th>
richt@239
  1026
            </tr>
richt@239
  1027
          </thead>
richt@239
  1028
          <tbody>
richt@239
  1029
            <tr>
richt@239
  1030
              <td>
richt@239
  1031
                <dfn id="dom-networkservice-onnotify"
richt@239
  1032
                    title="dom-NetworkService-onnotify"><code>onnotify</code></dfn>
richt@239
  1033
              </td>
richt@239
  1034
              <td>
richt@239
  1035
                <a href="#event-notify"><code>notify</code></a>
richt@239
  1036
              </td>
richt@239
  1037
            </tr>
richt@239
  1038
            <tr>
richt@239
  1039
              <td>
richt@239
  1040
                <dfn id="dom-networkservice-onserviceonline"
richt@239
  1041
                    title="dom-NetworkService-onserviceonline"><code>onserviceonline</code></dfn>
richt@239
  1042
              </td>
richt@239
  1043
              <td>
richt@239
  1044
                <a href="#event-serviceonline"><code>serviceonline</code></a>
richt@239
  1045
              </td>
richt@239
  1046
            </tr>
richt@239
  1047
            <tr>
richt@239
  1048
              <td>
richt@239
  1049
                <dfn id="dom-networkservice-onserviceoffline"
richt@239
  1050
                    title="dom-NetworkService-onserviceoffline"><code>onserviceoffline</code></dfn>
richt@239
  1051
              </td>
richt@239
  1052
              <td>
richt@239
  1053
                <a href="#event-serviceoffline"><code>serviceoffline</code></a>
richt@239
  1054
              </td>
richt@239
  1055
            </tr>
richt@239
  1056
          </tbody>
richt@239
  1057
        </table>
richt@239
  1058
      </section>
richt@239
  1059
    </section>
richt@239
  1060
    <section>
richt@239
  1061
      <h2>
richt@239
  1062
        Service Discovery
richt@239
  1063
      </h2>
richt@239
  1064
      <p>
richt@243
  1065
        A <a>user agent</a> conforming to this specification MAY implement <abbr title=
richt@373
  1066
        "Simple Service Discovery Protocol">SSDP</abbr> [[!UPNP-DEVICEARCH11]], Zeroconf [[!DNS-SD]] + [[!MDNS]] and/or
richt@371
  1067
        <abbr title="Discovery and Launch Protocol">DIAL</abbr> [<a href=
richt@371
  1068
        "https://sites.google.com/a/dial-multiscreen.org/dial/dial-protocol-specification">DIAL</a>] <dfn>service
richt@371
  1069
        discovery mechanisms</dfn> - the requirements detailed in this section of the specification - to enable Web
richt@373
  1070
        pages to request and connect with HTTP services running on networked devices, discovered via any of these
richt@373
  1071
        mechanisms, through this API. When a <a>user agent</a> implements any of these <a>service discovery
richt@373
  1072
        mechanisms</a>, then it MUST conform to the corresponding algorithms provided in this section of the
richt@373
  1073
        specification.
richt@239
  1074
      </p>
richt@239
  1075
      <p>
richt@373
  1076
        This section presents how the results of these <a>service discovery mechanisms</a> will be matched to requested
richt@373
  1077
        service types, how the user agent stores available and active services and how their properties are applied to
richt@373
  1078
        any resulting <a href="#networkservice"><code>NetworkService</code></a> objects.
richt@239
  1079
      </p>
richt@239
  1080
      <p>
richt@250
  1081
        It is expected that user agents will perform these <a>service discovery mechanisms</a> asynchronously and
richt@250
  1082
        periodically update the <a>list of available service records</a> as required. The timing of any <a>service
richt@250
  1083
        discovery mechanisms</a> is an implementation detail left to the discretion of the implementer (e.g. by
richt@250
  1084
        continuously monitoring the network as a background process or on invocation of this API from a Web page).
richt@239
  1085
      </p>
richt@239
  1086
      <p>
richt@239
  1087
        The <dfn>list of available service records</dfn> is a single dynamic internal lookup table within user agents
richt@239
  1088
        that is used to track all the services that have been discovered and are available in the current network at
richt@440
  1089
        the current time. At any point during the running of any of the <a>service discovery mechanisms</a> then
richt@250
  1090
        existing entries within this table can be updated, entries can be added and entries can be removed as the
richt@250
  1091
        status of networked services changes according to the rules defined in this specification.
richt@239
  1092
      </p>
richt@239
  1093
      <p>
richt@250
  1094
        The <dfn>list of active service managers</dfn> is an internal list within user agents that is used to track all
richt@250
  1095
        <a href="#networkservices"><code>NetworkServices</code></a> objects currently being shared with any web pages
richt@371
  1096
        at the current time within the user agent. Each <a href="#networkservices"><code>NetworkServices</code></a>
richt@371
  1097
        object in the <a>list of active service managers</a> represents a collection of zero or more <a href=
richt@250
  1098
        "#networkservice"><code>NetworkService</code></a> objects - known as its <dfn>indexed properties</dfn>.
richt@250
  1099
        <a href="#networkservice"><code>NetworkService</code></a> objects are attached as the <a>indexed properties</a>
richt@250
  1100
        of a <a href="#networkservices"><code>NetworkServices</code></a> object as part of the <a href=
richt@239
  1101
        "#dom-navigator-getnetworkservices"><code>getNetworkServices()</code></a> algorithm.
richt@239
  1102
      </p>
richt@239
  1103
      <p>
richt@387
  1104
        The rule for <dfn>adding an available service</dfn> is the process of adding a <a>new service</a> or updating
richt@387
  1105
        an <a>existing service</a> that is generally available on the user's current network in the <a>list of
richt@387
  1106
        available service records</a>. This rule takes one argument, <var>network service record</var>, and consists of
richt@387
  1107
        running the following steps:
richt@239
  1108
      </p>
richt@239
  1109
      <ol class="rule">
richt@239
  1110
        <li>For each <var>existing service record</var> in the current <a>list of available service records</a>, run
richt@239
  1111
        the following sub-steps:
richt@239
  1112
          <ol class="rule">
richt@239
  1113
            <li>If the <var>existing service record</var>'s <code>id</code> property does not equal <var>network
richt@239
  1114
            service record</var>'s <code>id</code> property then abort any remaining sub-steps and continue at the next
richt@239
  1115
            available <var>existing service record</var>.
richt@239
  1116
            </li>
richt@239
  1117
            <li>Replace the value of <var>existing service record</var> in the current <a>list of available service
richt@373
  1118
            records</a> with the value of <var>network service record</var>, aborting any remaining steps in this
richt@373
  1119
            algorithm and return.
richt@239
  1120
            </li>
richt@239
  1121
          </ol>
richt@239
  1122
        </li>
richt@373
  1123
        <li>Add <var>network service record</var> to the <a>list of available service records</a> as a new item.
richt@239
  1124
        </li>
richt@250
  1125
        <li>For each <var>service manager</var> in the <a>list of active service managers</a> run the following steps:
richt@239
  1126
          <ol class="rule">
richt@250
  1127
            <li>For each <var>active service</var> in <var>service manager</var> run the following steps:
richt@250
  1128
              <ol class="rule">
richt@373
  1129
                <li>If the <var>network service record</var>'s <code>id</code> property equals the <var>active
richt@392
  1130
                service</var>'s <code>id</code> attribute and <var>active service</var>'s <code>online</code> attribute
richt@392
  1131
                is currently set to <code>false</code> then set <var>active service</var>'s <a href=
richt@250
  1132
                "#dom-networkservice-online"><code>online</code></a> attribute to <code>true</code> and then <a href=
richt@250
  1133
                "http://www.whatwg.org/specs/web-apps/current-work/complete/webappapis.html#queue-a-task"
richt@250
  1134
                      class="externalDFN">queue a task</a> to dispatch a newly created event with the name <a href=
richt@250
  1135
                      "#event-serviceonline"><code>serviceonline</code></a> that uses the <a href=
richt@250
  1136
                      "http://dvcs.w3.org/hg/domcore/raw-file/tip/Overview.html#event"
richt@250
  1137
                      class="externalDFN"><code>Event</code></a> interface, which does not bubble, is not cancellable,
richt@250
  1138
                      and has no default action, at the current <var>active service</var> object.
richt@250
  1139
                </li>
richt@250
  1140
              </ol>
richt@250
  1141
            </li>
richt@375
  1142
            <li>Let <var>'service type in current service manager' flag</var> be <code>false</code>.
richt@375
  1143
            </li>
richt@375
  1144
            <li>For each <var>requested control type</var> of the <var>requested control types</var> in <var>service
richt@375
  1145
            manager</var> run the following steps:
richt@375
  1146
              <ol class="rule">
richt@375
  1147
                <li>If <var>network service record</var>'s <code>type</code> property does not equal <var>requested
richt@375
  1148
                control type</var> then abort any remaining sub-steps and continue at the next available <var>requested
richt@375
  1149
                control type</var>.
richt@375
  1150
                </li>
richt@375
  1151
                <li>Set the <var>'service type in current service manager' flag</var> to <code>true</code>, abort any
richt@375
  1152
                remaining sub-steps and continue.
richt@375
  1153
                </li>
richt@375
  1154
              </ol>
richt@375
  1155
            </li>
richt@373
  1156
            <li>If the <var>'service type in current service manager' flag</var> is set to <code>true</code> then
richt@373
  1157
            increment <var>service manager</var>'s <a href=
richt@373
  1158
            "#dom-networkservices-servicesavailable"><code>servicesAvailable</code></a> attribute by <code>1</code> and
richt@373
  1159
            then <a href="http://www.whatwg.org/specs/web-apps/current-work/complete/webappapis.html#queue-a-task"
richt@239
  1160
                  class="externalDFN">queue a task</a> to dispatch a newly created event with the name <a href=
richt@239
  1161
                  "#event-serviceavailable"><code>serviceavailable</code></a> that uses the <a href=
richt@239
  1162
                  "http://dvcs.w3.org/hg/domcore/raw-file/tip/Overview.html#event"
richt@239
  1163
                  class="externalDFN"><code>Event</code></a> interface, which does not bubble, is not cancellable, and
richt@250
  1164
                  has no default action, at the current <var>service manager</var> object.
richt@239
  1165
            </li>
richt@239
  1166
          </ol>
richt@239
  1167
        </li>
richt@239
  1168
      </ol>
richt@239
  1169
      <p>
richt@387
  1170
        The rule for <dfn>removing an available service</dfn> is the general process of removing an <a>existing
richt@387
  1171
        service</a> from the <a>list of available service records</a> that has left the user's current network or has
richt@387
  1172
        otherwise expired. This rule takes one argument, <var>service identifier</var>, and consists of running the
richt@387
  1173
        following steps:
richt@239
  1174
      </p>
richt@239
  1175
      <ol class="rule">
richt@239
  1176
        <li>For each <var>existing service record</var> in the current <a>list of available service records</a>, run
richt@239
  1177
        the following sub-steps:
richt@239
  1178
          <ol class="rule">
richt@239
  1179
            <li>If the <var>existing service record</var>'s <code>id</code> property does not match <var>service
richt@239
  1180
            identifier</var> then skip any remaining sub-steps for the current <var>existing service record</var> and
richt@239
  1181
            continue at the next available <var>existing service record</var>.
richt@239
  1182
            </li>
richt@378
  1183
            <li>Let <var>'service type in use' flag</var> be <code>false</code>.
richt@239
  1184
            </li>
richt@250
  1185
            <li>For each <var>service manager</var> in the <a>list of active service managers</a> run the following
richt@239
  1186
            steps:
richt@239
  1187
              <ol class="rule">
richt@373
  1188
                <li>Let <var>'service type in current service manager' flag</var> be <code>false</code>.
richt@239
  1189
                </li>
richt@250
  1190
                <li>For each <var>active service</var> in <var>service manager</var> run the following steps:
richt@250
  1191
                  <ol class="rule">
richt@250
  1192
                    <li>If <var>existing service record</var>'s <code>id</code> property equals the <var>active
richt@250
  1193
                    service</var>'s <code>id</code> attribute and <var>active service</var>'s <a href=
richt@250
  1194
                    "#dom-networkservice-online"><code>online</code></a> attribute is currently set to
richt@250
  1195
                    <code>true</code> then set <var>active service</var>'s <a href="#dom-networkservice-online"><code>
richt@250
  1196
                      online</code></a> attribute to <code>false</code> and then <a href=
richt@250
  1197
                      "http://www.whatwg.org/specs/web-apps/current-work/complete/webappapis.html#queue-a-task"
richt@250
  1198
                          class="externalDFN">queue a task</a> to dispatch a newly created event with the name <a href=
richt@250
  1199
                          "#event-serviceoffline"><code>serviceoffline</code></a> that uses the <a href=
richt@250
  1200
                          "http://dvcs.w3.org/hg/domcore/raw-file/tip/Overview.html#event"
richt@250
  1201
                          class="externalDFN"><code>Event</code></a> interface, which does not bubble, is not
richt@250
  1202
                          cancellable, and has no default action, at the current <var>active service</var>.
richt@250
  1203
                    </li>
richt@250
  1204
                  </ol>
richt@250
  1205
                </li>
richt@375
  1206
                <li>For each <var>requested control type</var> of the <var>requested control types</var> in
richt@375
  1207
                <var>service manager</var> run the following steps:
richt@375
  1208
                  <ol class="rule">
richt@375
  1209
                    <li>If <var>existing service record</var>'s <code>type</code> property does not equal
richt@375
  1210
                    <var>requested control type</var> then abort any remaining sub-steps and continue at the next
richt@375
  1211
                    available <var>requested control type</var>.
richt@375
  1212
                    </li>
richt@378
  1213
                    <li>Set the <var>'service type in current service manager' flag</var> to <code>true</code> and the
richt@378
  1214
                    <var>'service type in use' flag</var> to <code>true</code>, abort any remaining sub-steps and
richt@378
  1215
                    continue.
richt@375
  1216
                    </li>
richt@375
  1217
                  </ol>
richt@375
  1218
                </li>
richt@373
  1219
                <li>If the <var>'service type in current service manager' flag</var> is set to <code>true</code> then
richt@250
  1220
                decrement <var>service manager</var>'s <a href=
richt@250
  1221
                "#dom-networkservices-servicesavailable"><code>servicesAvailable</code></a> attribute by <code>1</code>
richt@250
  1222
                and then <a href=
richt@239
  1223
                "http://www.whatwg.org/specs/web-apps/current-work/complete/webappapis.html#queue-a-task"
richt@239
  1224
                      class="externalDFN">queue a task</a> to dispatch a newly created event with the name <a href=
richt@239
  1225
                      "#event-serviceunavailable"><code>serviceunavailable</code></a> that uses the <a href=
richt@239
  1226
                      "http://dvcs.w3.org/hg/domcore/raw-file/tip/Overview.html#event"
richt@239
  1227
                      class="externalDFN"><code>Event</code></a> interface, which does not bubble, is not cancellable,
richt@250
  1228
                      and has no default action, at the current <var>service manager</var> object.
richt@239
  1229
                </li>
richt@239
  1230
              </ol>
richt@239
  1231
            </li>
richt@378
  1232
            <li>If the <var>'service type in use' flag</var> is <code>false</code> and the <var>existing service
richt@378
  1233
            record</var>'s <code>type</code> property begins with the DOMString "<code>upnp:</code>" and <var>existing
richt@378
  1234
            service record</var>'s <code>eventsURL</code> property is set then run the rule to <a>terminate an existing
richt@378
  1235
            UPnP Events Subscription</a>, if one is currently active (as a result of having previously called <a>setup
richt@378
  1236
            a UPnP Events Subscription</a> against the current <var>existing service record</var>).
richt@378
  1237
            </li>
richt@239
  1238
            <li>Remove <var>existing service record</var> from the current <a>list of available service records</a>.
richt@239
  1239
            </li>
richt@239
  1240
          </ol>
richt@239
  1241
        </li>
richt@239
  1242
      </ol>
richt@239
  1243
      <p>
richt@250
  1244
        User agents SHOULD expire a service record from the <a>list of available service records</a> when its
richt@250
  1245
        <code>expiryTimestamp</code> attribute exceeds the current UTC timestamp. When this condition is met the
richt@250
  1246
        <a>user agent</a> SHOULD run the rule for <a>removing an available service</a>, passing in the expired service
richt@250
  1247
        record's <code>id</code> attribute as the only argument.
richt@239
  1248
      </p>
richt@239
  1249
      <section>
richt@239
  1250
        <h4>
richt@239
  1251
          Zeroconf (<abbr title="Multicast DNS">mDNS</abbr> + <abbr title="Domain Name System">DNS</abbr>-<abbr title=
richt@239
  1252
          "Service Discovery">SD</abbr>)
richt@239
  1253
        </h4>
richt@239
  1254
        <p>
richt@239
  1255
          For each DNS response received from a user-agent-initiated Multicast DNS Browse for <abbr title=
richt@239
  1256
          "DNS Pointer Record">PTR</abbr> records with the name <code>_services._dns-sd._udp</code> on the resolved
richt@250
  1257
          recommended automatic browsing domain [[!MDNS]], the <a>user agent</a> MUST run the following steps:
richt@239
  1258
        </p>
richt@239
  1259
        <ol class="rule">
richt@239
  1260
          <li>Let <var>service mDNS responses</var> be an array of PTR records received by issuing a Multicast DNS
richt@239
  1261
          Browse for PTR records with the name of the current discovered service type.
richt@239
  1262
          </li>
richt@239
  1263
          <li>For each Object <var>service mDNS response</var> in <var>service mDNS responses</var>, run the following
richt@239
  1264
          steps:
richt@239
  1265
            <ol>
richt@239
  1266
              <li>Let <var>network service record</var> be an Object consisting of the following empty properties:
richt@239
  1267
              <code>id</code>, <code>name</code>, <code>type</code>, <code>url</code>, <code>config</code>,
richt@239
  1268
              <code>expiryTimestamp</code>.
richt@239
  1269
              </li>
richt@239
  1270
              <li>Set <var>network service record</var>'s <code>id</code> property to the value of the full PTR Service
richt@239
  1271
              Instance Name [[!MDNS]].
richt@239
  1272
              </li>
richt@239
  1273
              <li>Set <var>network service record</var>'s <code>name</code> property to the value of the PTR Service
richt@239
  1274
              Instance Name's <var>Instance</var> component [[!MDNS]].
richt@239
  1275
              </li>
richt@239
  1276
              <li>Set <var>network service record</var>'s <code>type</code> property to the concatenation of the string
richt@239
  1277
              <code>zeroconf:</code> followed be the value of the PTR Service Instance Name's <var>Service</var>
richt@239
  1278
              component [[!MDNS]].
richt@239
  1279
              </li>
richt@239
  1280
              <li>Set <var>network service record</var>'s <code>url</code> property to the resolvable Service URL
richt@239
  1281
              obtained from performing an DNS-SD Lookup [[!DNS-SD]] of the current service from the PTR record provided
richt@239
  1282
              [[!MDNS]].
richt@239
  1283
              </li>
richt@239
  1284
              <li>Set <var>network service record</var>'s <code>config</code> property to the string value of the
richt@239
  1285
              contents of the first DNS-SD TXT record associated with the <var>service mDNS response</var> as defined
richt@239
  1286
              in [[!DNS-SD]].
richt@239
  1287
              </li>
richt@239
  1288
              <li>Set <var>network service record</var>'s <code>expiryTimestamp</code> property to the value of the
richt@239
  1289
              current date, in UTC timestamp format, plus a value of <code>120</code> seconds.
richt@239
  1290
              </li>
richt@239
  1291
              <li>Run the general rule for <a>adding an available service</a>, passing in the current <var>network
richt@239
  1292
              service record</var> as the only argument.
richt@239
  1293
              </li>
richt@239
  1294
            </ol>
richt@239
  1295
          </li>
richt@239
  1296
        </ol>
richt@239
  1297
      </section>
richt@239
  1298
      <section>
richt@239
  1299
        <h5>
richt@239
  1300
          Simple Service Discovery Protocol (<abbr title="Simple Service Discovery Protocol">SSDP</abbr>)
richt@239
  1301
        </h5>
richt@239
  1302
        <p>
richt@250
  1303
          A user agent that implements UPnP service discovery MUST issue a <dfn>search request for UPnP root
richt@250
  1304
          devices</dfn> against the user's current local network according to the full normative text and timing
richt@250
  1305
          provided in 'Section 1.3.2: Search request with M-SEARCH' detailed in [[!UPNP-DEVICEARCH11]].
richt@239
  1306
        </p>
richt@239
  1307
        <p>
richt@250
  1308
          The user agent MUST issue all <a title="search request for UPnP root devices">search requests for UPnP root
richt@250
  1309
          devices</a> with a HTTP request line equal to <code>M-SEARCH * HTTP/1.1</code>, with a HOST header equal to
richt@372
  1310
          the reserved multicast address and port of <code>239.255.255.250:1900</code> and a MAN header equal to
richt@372
  1311
          <code>ssdp:discover</code>. The <a>user agent</a> must also send an ST header with this HTTP request equal to
richt@372
  1312
          the String value of <code>ssdp:all</code> or <code>upnp:rootdevice</code> or a single <a>valid service
richt@391
  1313
          type</a> token beginning with the String value <code>upnp:</code>. If a single <a>valid service type</a>
richt@391
  1314
          token beginning with the String value <code>upnp:</code> is to be used, the user agent MUST strip the leading
richt@391
  1315
          String <code>upnp:</code> before using this value in this HTTP request. The user-agent MUST also send an MX
richt@391
  1316
          header equal to a <dfn>maximum UPnP advertisement response wait time</dfn> value between <code>1</code> and
richt@391
  1317
          <code>5</code> seconds with this HTTP request.
richt@239
  1318
        </p>
richt@239
  1319
        <p>
richt@250
  1320
          The user agent MUST listen for any incoming responses to any <a>search request for UPnP root devices</a>.
richt@239
  1321
        </p>
richt@239
  1322
        <p>
richt@250
  1323
          For each <dfn>HTTP Response</dfn> following an initial <a>search request for UPnP root devices</a> sent on a
richt@240
  1324
          <a>standard UPnP address and port</a> the user agent MUST run the following steps:
richt@239
  1325
        </p>
richt@239
  1326
        <ol class="rule">
richt@239
  1327
          <li>If the <a>HTTP Response</a> is not a HTTP 200 OK response then this response is invalid and the user
richt@250
  1328
          agent MUST discard this response, abort any remaining steps and return. The user agent MAY issue a new
richt@250
  1329
          <a>search request for UPnP root devices</a> as a result of this error occurring.
richt@250
  1330
          </li>
richt@250
  1331
          <li>If the <a>maximum UPnP advertisement response wait time</a> has been exceeded since the initial <a>search
richt@250
  1332
          request for UPnP root devices</a> was sent then the <a>HTTP Response</a> is invalid and the user agent MUST
richt@250
  1333
          discard this response, abort any remaining steps and return. The user agent MAY stop listening for responses
richt@250
  1334
          from the current <a>search request for UPnP root devices</a> as a result of this error occurring. Equally,
richt@250
  1335
          the user agent MAY issue a new <a>search request for UPnP root devices</a> as a result of this error
richt@239
  1336
          occurring.
richt@239
  1337
          </li>
richt@239
  1338
          <li>Let <var>ssdp device</var> be an Object with a property for each HTTP header received in the <a>HTTP
richt@239
  1339
          Response</a>, with each key being the name of a HTTP response header and each value being that HTTP response
richt@239
  1340
          header's value.
richt@239
  1341
          </li>
richt@239
  1342
          <li>If <var>ssdp device</var> does not contain at least one <var>CACHE-CONTROL</var> entry, at least one
richt@374
  1343
          <var>USN</var> entry, at least one <var>ST</var> entry and at least one <var>LOCATION</var> entry then the
richt@374
  1344
          <a>HTTP Response</a> is invalid and the <a>user agent</a> MUST discard this response, abort any remaining
richt@374
  1345
          steps and return.
richt@239
  1346
          </li>
richt@250
  1347
          <li>The user agent MUST run the rule for <a>obtaining a UPnP Device Description File</a> passing in the first
richt@250
  1348
          occurrence of <var>LOCATION</var> from <var>ssdp device</var> as the <var>device descriptor URL</var>
richt@250
  1349
          argument and the first occurrence of <var>USN</var> from <var>ssdp device</var> as the <var>device
richt@250
  1350
          identifier</var> argument and the first occurrence of <var>CACHE-CONTROL</var> from <var>ssdp device</var>
richt@250
  1351
          (minus the leading string of <code>max-age=</code>) as the <var>device expiry</var> argument.
richt@239
  1352
          </li>
richt@239
  1353
        </ol>
richt@239
  1354
        <p>
richt@250
  1355
          The user agent MUST listen for incoming requests on the <dfn>standard UPnP address and port</dfn> on all
richt@250
  1356
          current local network interface addresses with the port <code>1900</code>.
richt@250
  1357
        </p>
richt@250
  1358
        <p>
richt@250
  1359
          For each <dfn>HTTP Request</dfn> received on a <a>standard UPnP address and port</a> the user agent MUST run
richt@250
  1360
          the following steps:
richt@239
  1361
        </p>
richt@239
  1362
        <ol class="rule">
richt@239
  1363
          <li>If the <a>HTTP Request</a> is not a HTTP NOTIFY request then it is not a valid UPnP Request and the user
richt@250
  1364
          agent MUST discard this request, abort any remaining steps and return.
richt@239
  1365
          </li>
richt@239
  1366
          <li>Let <var>ssdp device</var> be an Object with a property for each HTTP header received in the <a>HTTP
richt@239
  1367
          Request</a>, with each key being the name of a HTTP header and each value being that HTTP header's value.
richt@239
  1368
          </li>
richt@374
  1369
          <li>If <var>ssdp device</var>'s <var>NTS</var> entry is equal to <code>ssdp:alive</code> and the <a>HTTP
richt@374
  1370
          Request</a> does not contain at least one <var>CACHE-CONTROL</var> entry, at least one <var>USN</var> entry,
richt@374
  1371
          at least one <var>NT</var> entry, at least one <var>NTS</var> entry and at least one <var>LOCATION</var>
richt@374
  1372
          entry, then the <a>user agent</a> MUST discard this request, abort any remaining steps and return.
richt@239
  1373
          </li>
richt@250
  1374
          <li>If <var>ssdp device</var>'s <var>NTS</var> entry is equal to <code>ssdp:alive</code> then the user agent
richt@250
  1375
          MUST run the rule for <a>obtaining a UPnP Device Description File</a> passing in the first occurrence of
richt@250
  1376
          <var>LOCATION</var> from <var>ssdp device</var> as the <var>device descriptor URL</var> argument and the
richt@250
  1377
          first occurrence of <var>USN</var> from <var>ssdp device</var> as the <var>device identifier</var> argument
richt@250
  1378
          and the first occurrence of <var>CACHE-CONTROL</var> from <var>ssdp device</var> (minus the leading string of
richt@250
  1379
          <code>max-age=</code>) as the <var>device expiry</var>.<br>
richt@239
  1380
            <br>
richt@239
  1381
            Otherwise, if <var>ssdp device</var>'s <var>NTS</var> entry is equal to <code>ssdp:byebye</code> then the
richt@250
  1382
            user agent MUST run the rule for <a>removing all services from a registered UPnP Device</a> passing in the
richt@250
  1383
            first occurrence of <var>USN</var> from <var>ssdp device</var> as the <var>device identifier</var>
richt@250
  1384
            argument.
richt@239
  1385
          </li>
richt@239
  1386
        </ol>
richt@239
  1387
        <p>
richt@239
  1388
          The rule for <dfn>obtaining a UPnP Device Description File</dfn> is the process of obtaining the contents of
richt@239
  1389
          a standard UPnP Device Description [[!UPNP-DEVICEARCH11]] from a URL-based resource. This rule takes three
richt@239
  1390
          arguments - <var>device descriptor URL</var>, <var>device identifier</var> and <var>device expiry</var> - and
richt@240
  1391
          when called the user agent MUST run the following steps:
richt@239
  1392
        </p>
richt@239
  1393
        <ol class="rule">
richt@239
  1394
          <li>Let <var>device descriptor file</var> contain the contents of the file located at the URL provided in
richt@239
  1395
          <var>device descriptor URL</var> obtained according to the rules defined in 'Section 2.11: Retrieving a
richt@239
  1396
          description using HTTP' in [[!UPNP-DEVICEARCH11]].
richt@239
  1397
          </li>
richt@239
  1398
          <li>If the value provided in <var>device descriptor URL</var> cannot be resolved as a reachable URL on the
richt@250
  1399
          current network or the <var>device descriptor file</var> remains empty then it is invalid and the <a>user
richt@250
  1400
          agent</a> MUST abort any remaining steps and return.
richt@239
  1401
          </li>
richt@239
  1402
          <li>Run the rule for <a>processing a UPnP Device Description File</a>, passing in the current <var>device
richt@239
  1403
          descriptor file</var>, <var>device identifier</var> and <var>device expiry</var> arguments.
richt@239
  1404
          </li>
richt@239
  1405
        </ol>
richt@239
  1406
        <p>
richt@239
  1407
          The rule for <dfn>processing a UPnP Device Description File</dfn> is the process of parsing the contents of a
richt@239
  1408
          standard UPnP Device Description [[!UPNP-DEVICEARCH11]] and registering the UPnP services contained therein
richt@239
  1409
          within the <a>list of available service records</a>.
richt@239
  1410
        </p>
richt@239
  1411
        <p>
richt@239
  1412
          The rule for <a>processing a UPnP Device Description File</a> takes three arguments - <var>device descriptor
richt@250
  1413
          file</var>, <var>device identifier</var> and <var>device expiry</var> - and when called the user agent MUST
richt@250
  1414
          run the following steps:
richt@239
  1415
        </p>
richt@239
  1416
        <ol class="rule">
richt@239
  1417
          <li>Let <var>advertised services</var> be a list of all advertised services obtained from the <var>device
richt@239
  1418
          descriptor file</var> containing the value of the first occurrence of the <code>&lt;serviceList&gt;</code>
richt@239
  1419
          element as it is defined in 'Section 2.3: Device Description' in [[!UPNP-DEVICEARCH11]].
richt@239
  1420
          </li>
richt@239
  1421
          <li>For each <code>&lt;service&gt;</code> element - known as an <var>advertised service</var> - in
richt@239
  1422
          <var>advertised services</var> run the following steps:
richt@239
  1423
            <ol class="rule">
richt@239
  1424
              <li>Let <var>network service record</var> be a new Object consisting of the following empty properties:
richt@239
  1425
              <code>id</code>, <code>deviceId</code>, <code>name</code>, <code>type</code>, <code>url</code>,
richt@239
  1426
              <code>eventsUrl</code>, <code>config</code>, <code>expiryTimestamp</code>.
richt@239
  1427
              </li>
richt@239
  1428
              <li>Set <var>network service record</var>'s <code>id</code> property to the concatenated string value of
richt@250
  1429
              the first occurrence of the <code>&lt;UDN&gt;</code> element in the <var>device descriptor file</var>
richt@250
  1430
              with the <var>advertised service</var>'s <code>&lt;serviceId&gt;</code> sub-element.
richt@239
  1431
              </li>
richt@239
  1432
              <li>Set <var>network service record</var>'s <code>deviceId</code> property to the value of <var>device
richt@239
  1433
              identifier</var>.
richt@239
  1434
              </li>
richt@239
  1435
              <li>Set <var>network service record</var>'s <code>name</code> property to the string value of the first
richt@239
  1436
              occurrence of the <var>advertised service</var>'s <code>&lt;serviceId&gt;</code> sub-element.
richt@239
  1437
              </li>
richt@239
  1438
              <li>Set <var>network service record</var>'s <code>type</code> property to the concatenation of the string
richt@239
  1439
              <code>upnp:</code> followed by the string value of the first occurrence of the <var>advertised
richt@239
  1440
              service</var>'s <code>&lt;serviceType&gt;</code> sub-element.
richt@239
  1441
              </li>
richt@239
  1442
              <li>Set <var>network service record</var>'s <code>url</code> property to the string value of the first
richt@239
  1443
              occurrence of the <var>advertised service</var>'s <code>&lt;controlURL&gt;</code> sub-element.
richt@239
  1444
              </li>
richt@239
  1445
              <li>Set <var>network service record</var>'s <code>config</code> property to the string value of the
richt@239
  1446
              contents of the first occurrence of the <code>&lt;device&gt;</code> element in the <var>device descriptor
richt@239
  1447
              file</var>.
richt@239
  1448
              </li>
richt@239
  1449
              <li>If <var>advertised service</var>'s <code>&lt;eventSubURL&gt;</code> sub-element is not empty, then
richt@239
  1450
              set <var>network service record</var>'s <code>eventsUrl</code> property to the string value of the first
richt@239
  1451
              occurrence of the <var>advertised service</var>'s <code>&lt;eventSubURL&gt;</code> sub-element.
richt@239
  1452
              Otherwise, do not set <var>network service record</var>'s <code>eventsUrl</code> property.
richt@239
  1453
              </li>
richt@239
  1454
              <li>Set <var>network service record</var>'s <code>expiryTimestamp</code> property to the value of the
richt@239
  1455
              current date, in UTC timestamp format, plus the value of <var>device expiry</var>.
richt@239
  1456
              </li>
richt@239
  1457
              <li>Run the general rule for <a>adding an available service</a>, passing in the current <var>network
richt@239
  1458
              service record</var> as the only argument.
richt@239
  1459
              </li>
richt@239
  1460
            </ol>
richt@239
  1461
          </li>
richt@250
  1462
          <li>If <var>device descriptor file</var> contains a <code>&lt;deviceList&gt;</code> element then for each
richt@250
  1463
          <code>&lt;device&gt;</code> element within <code>&lt;deviceList&gt;</code> - herein known as an <var>embedded
richt@250
  1464
          device descriptor file</var> - the user agent MUST run the rule for <a>processing a UPnP Device Description
richt@250
  1465
          File</a>, passing in the current <var>embedded device descriptor file</var> as the <var>device descriptor
richt@250
  1466
          file</var> argument, along with the current <var>device identifier</var> and <var>device expiry</var>
richt@250
  1467
          arguments.
richt@250
  1468
          </li>
richt@239
  1469
        </ol>
richt@239
  1470
        <p>
richt@239
  1471
          The rule for <dfn>removing all services from a registered UPnP Device</dfn> is the process of removing all
richt@239
  1472
          services associated with a device from the <a>list of available service records</a> that has left the user's
richt@239
  1473
          current network or has otherwise timed out or expired. This rule takes one argument, <var>device
richt@239
  1474
          identifier</var>, and consists of running the following steps:
richt@239
  1475
        </p>
richt@239
  1476
        <ol class="rule">
richt@239
  1477
          <li>For each <var>existing service record</var> in the current <a>list of available service records</a>, run
richt@239
  1478
          the following sub-steps:
richt@239
  1479
            <ol class="rule">
richt@239
  1480
              <li>If the <var>existing service record</var>'s <code>deviceId</code> property does not match <var>device
richt@239
  1481
              identifier</var> then skip any remaining sub-steps for the current <var>existing service record</var> and
richt@239
  1482
              continue at the next available <var>existing service record</var>.
richt@239
  1483
              </li>
richt@239
  1484
              <li>Run the general rule for <a>removing an available service</a> passing in <var>existing service
richt@239
  1485
              record</var>'s <code>id</code> property as the only argument.
richt@239
  1486
              </li>
richt@239
  1487
            </ol>
richt@239
  1488
          </li>
richt@239
  1489
        </ol>
richt@239
  1490
        <p>
richt@239
  1491
          When the <a>user agent</a> is to <dfn>setup a UPnP Events Subscription</dfn>, it is to run the following
richt@239
  1492
          steps with the current <var>network service record</var> object as defined in 'Section 4.1.2: SUBSCRIBE with
richt@239
  1493
          NT and CALLBACK' in [[!UPNP-DEVICEARCH11]]:
richt@239
  1494
        </p>
richt@239
  1495
        <ol class="rule">
richt@239
  1496
          <li>If <var>network service record</var>'s <code>eventsUrl</code> property is empty then the <a>user
richt@240
  1497
          agent</a> MUST abort these steps.
richt@239
  1498
          </li>
richt@239
  1499
          <li>Let <var>callback URL</var> be the value of creating a new <a>user-agent generated callback url</a>.
richt@239
  1500
          </li>
richt@239
  1501
          <li>Send a HTTP SUBSCRIBE request with a <em>NT</em> header with a string value of <code>upnp:event</code>, a
richt@239
  1502
          <em>TIMEOUT</em> header with a user-agent defined timeout value (in the form <code>Second-XX</code> where
richt@239
  1503
          <code>XX</code> is the user-agent defined timeout value in seconds) and a <em>CALLBACK</em> header with a
richt@239
  1504
          string value of <var>callback URL</var> towards the <var>network service record</var>'s
richt@239
  1505
          <code>eventsUrl</code> property.
richt@239
  1506
          </li>
richt@250
  1507
          <li>If a non-200 OK response is received from the HTTP SUBSCRIBE request then the <a>user agent</a> MUST
richt@250
  1508
          abort these steps.
richt@239
  1509
          </li>
richt@239
  1510
          <li>On receiving a valid 200 OK response, run the following steps:
richt@239
  1511
            <ol class="rule">
richt@239
  1512
              <li>Let <var>callback ID</var> equal the string value of the first included <em>SID</em> header, if it
richt@239
  1513
              exists.
richt@239
  1514
              </li>
richt@239
  1515
              <li>Let <var>timeout date</var> equal the sum of the current UTC date value plus the integer value of the
richt@239
  1516
              first included <em>TIMEOUT</em> header (minus the leading string of <code>Second-</code>), if it exists.
richt@239
  1517
              </li>
richt@240
  1518
              <li>Run the following steps asynchronously and continue to the step labeled <em>listen</em> below.
richt@239
  1519
              </li>
richt@239
  1520
              <li>
richt@239
  1521
                <em>Refresh Subscription</em>: Run the following steps at a set interval (X) within the <a>user
richt@239
  1522
                agent</a>:
richt@239
  1523
                <ol class="rule">
richt@239
  1524
                  <li>Let <var>current date</var> equal the current UTC date.
richt@239
  1525
                  </li>
richt@239
  1526
                  <li>If <var>current date</var> is less than the <var>timeout date</var> then continue to the step
richt@239
  1527
                  labeled <em>refresh subscription</em> above.
richt@239
  1528
                  </li>
richt@239
  1529
                  <li>Send a HTTP SUBSCRIBE request with a <em>SID</em> header with the string value of <var>callback
richt@239
  1530
                  ID</var> and a user-agent defined <em>TIMEOUT</em> header (in the form <code>Second-XX</code> where
richt@239
  1531
                  <code>XX</code> is the user-agent defined timeout value in seconds) towards the <var>network service
richt@239
  1532
                  record</var>'s <code>eventsUrl</code> property.
richt@239
  1533
                  </li>
richt@239
  1534
                  <li>On receiving a valid 200 OK, update <var>callback ID</var> with the string value of the first
richt@250
  1535
                  included <em>SID</em> header and set <var>timeout date</var> to the sum of the current UTC date value
richt@250
  1536
                  plus the integer value of the first included <em>TIMEOUT</em> header (minus the leading string of
richt@250
  1537
                  <code>Second-</code>), if it exists. If the current date is greater than or equal to <var>timeout
richt@250
  1538
                  date</var> then the <a>user agent</a> SHOULD continue from the step labeled <em>refresh
richt@250
  1539
                  subscription</em> above. For all non 200 OK responses the <a>user agent</a> SHOULD continue from the
richt@250
  1540
                  step labeled <em>refresh subscription</em> above.
richt@239
  1541
                  </li>
richt@239
  1542
                </ol>
richt@239
  1543
              </li>
richt@239
  1544
              <li>
richt@239
  1545
                <em>Listen</em>: For each HTTP NOTIFY request received at the <var>callback URL</var> the <a>user
richt@239
  1546
                agent</a> is to run the following steps:
richt@239
  1547
                <ol class="rule">
richt@239
  1548
                  <li>Let <var>content clone</var> be the result of obtaining the message body of the HTTP NOTIFY
richt@250
  1549
                  request. If <var>content clone</var> is empty, then the <a>user agent</a> MUST abort these steps.
richt@239
  1550
                  </li>
richt@239
  1551
                  <li>Let <var>notification event</var> be a new simple event that uses the <a href=
richt@239
  1552
                  "http://dvcs.w3.org/hg/domcore/raw-file/tip/Overview.html#event"
richt@239
  1553
                        class="externalDFN"><code>Event</code></a> interface with the name <a href=
richt@239
  1554
                        "#event-notify"><code>notify</code></a>, which does not bubble, is not cancellable, and has no
richt@239
  1555
                        default action.
richt@239
  1556
                  </li>
richt@239
  1557
                  <li>Let the <code>data</code> attribute of <var>notification event</var> have the DOMString value of
richt@239
  1558
                  <var>content clone</var>.
richt@239
  1559
                  </li>
richt@239
  1560
                  <li>
richt@239
  1561
                    <a href="http://www.whatwg.org/specs/web-apps/current-work/complete/webappapis.html#queue-a-task"
richt@239
  1562
                        class="externalDFN">Queue a task</a> to dispatch <var>notification event</var> at the current
richt@239
  1563
                        <a><code>NetworkService</code></a> object.
richt@239
  1564
                  </li>
richt@250
  1565
                  <li>Return a HTTP 200 OK response to the sender of the HTTP NOTIFY request.
richt@250
  1566
                  </li>
richt@239
  1567
                </ol>
richt@239
  1568
              </li>
richt@239
  1569
            </ol>
richt@239
  1570
          </li>
richt@239
  1571
        </ol>
richt@239
  1572
        <p>
richt@250
  1573
          A <a>user agent</a> can <dfn>terminate an existing UPnP Events Subscription</dfn> at any time for a
richt@250
  1574
          <var>network service record</var> by sending an HTTP UNSUBSCRIBE request - as defined in 'Section 4.1.4:
richt@250
  1575
          Cancelling a subscription with UNSUBSCRIBE' in [[!UPNP-DEVICEARCH11]] - with a HOST header set to that
richt@250
  1576
          <var>active service</var>'s <code>eventsUrl</code> property and a SID header set to the <var>callback
richt@250
  1577
          ID</var> obtained when the initial <a>setup a UPnP Events Subscription</a> action occurred.
richt@239
  1578
        </p>
richt@239
  1579
      </section>
richt@239
  1580
      <section>
danieldanciu@330
  1581
        <h5>
danieldanciu@330
  1582
          Discovery and Launch Protocol (<abbr title="Discovery and Launch Protocol">DIAL</abbr>)
danieldanciu@330
  1583
        </h5>
richt@371
  1584
        <p>
danieldanciu@330
  1585
          A user agent that implements DIAL service discovery MUST issue a <dfn>search request for DIAL-enabled
danieldanciu@330
  1586
          devices</dfn> against the user's current local network according to the full normative text and timing
danieldanciu@330
  1587
          provided in 'Section 1.3.2: Search request with M-SEARCH' detailed in [[!UPNP-DEVICEARCH11]].
danieldanciu@330
  1588
        </p>
danieldanciu@330
  1589
        <p>
richt@371
  1590
          Let <var>dial version</var> be the version number specified in the <a>valid service type</a> token. Let
richt@371
  1591
          <var>dial search target</var> be the concatentation of the
danieldanciu@330
  1592
          <code>urn:dial-multiscreen-org:service:dial:</code> string constant with the <var>dial version</var>
richt@332
  1593
          (currently, <var>dial version</var> can only be <code>1</code>)
danieldanciu@330
  1594
        </p>
danieldanciu@330
  1595
        <p>
richt@371
  1596
          The user agent MUST issue all <a title="search request for DIAL devices">search requests for DIAL devices</a>
richt@371
  1597
          with a HTTP request line equal to <code>M-SEARCH * HTTP/1.1</code>, with a HOST header equal to the reserved
richt@371
  1598
          multicast address and port of <code>239.255.255.250:1900</code>, a MAN header equal to
richt@371
  1599
          <code>ssdp:discover</code>, an ST header equal to <var>dial search target</var> and a user-agent defined MX
richt@371
  1600
          header equal to a <dfn>maximum DIAL advertisement response wait time</dfn> value between <code>1</code> and
richt@371
  1601
          <code>5</code> seconds.
danieldanciu@330
  1602
        </p>
danieldanciu@330
  1603
        <p>
danieldanciu@330
  1604
          The user agent MUST listen for any incoming responses to a <a>search request for DIAL devices</a>.
danieldanciu@330
  1605
        </p>
danieldanciu@330
  1606
        <p>
richt@371
  1607
          For each HTTP Response following an initial <a>search request for DIAL devices</a> sent on a <a>standard UPnP
richt@371
  1608
          address and port</a> the user agent MUST run the following steps:
danieldanciu@330
  1609
        </p>
danieldanciu@330
  1610
        <ol class="rule">
richt@371
  1611
          <li>If the HTTP Response is not a HTTP 200 OK response then this response is invalid and the user agent MUST
richt@371
  1612
          discard this response, abort any remaining steps and return. The user agent MAY issue a new <a>search request
richt@371
  1613
          for DIAL devices</a> as a result of this error occurring.
danieldanciu@330
  1614
          </li>
richt@332
  1615
          <li>If the <a>maximum DIAL advertisement response wait time</a> has been exceeded since the initial <a>search
danieldanciu@330
  1616
          request for DIAL devices</a> was sent then the <a>HTTP Response</a> is invalid and the user agent MUST
danieldanciu@330
  1617
          discard this response, abort any remaining steps and return. The user agent MAY stop listening for responses
richt@371
  1618
          from the current <a>search request for DIAL devices</a> as a result of this error occurring. Equally, the
richt@371
  1619
          user agent MAY issue a new <a>search request for DIAL devices</a> as a result of this error occurring.
danieldanciu@330
  1620
          </li>
danieldanciu@330
  1621
          <li>Let <var>dial device</var> be an Object with a property for each HTTP header received in the <a>HTTP
danieldanciu@330
  1622
          Response</a>, with each key being the name of a HTTP response header and each value being that HTTP response
danieldanciu@330
  1623
          header's value.
danieldanciu@330
  1624
          </li>
danieldanciu@330
  1625
          <li>If <var>dial device</var> does not contain at least one <var>CACHE-CONTROL</var> entry, at least one
danieldanciu@330
  1626
          <var>USN</var> entry, at least one <var>ST</var> entry and at least one <var>LOCATION</var> entry or the
richt@371
  1627
          value of its <var>ST</var> entry is not <var>dial search target</var>, then the <a>HTTP Response</a> is
richt@371
  1628
          invalid and the <a>user agent</a> MUST discard this response, abort any remaining steps and return.
danieldanciu@330
  1629
          </li>
danieldanciu@330
  1630
          <li>The user agent MUST run the rule for <a>obtaining a UPnP Device Description File</a> passing in the first
danieldanciu@330
  1631
          occurrence of <var>LOCATION</var> from <var>dial device</var> as the <var>device descriptor URL</var>
danieldanciu@330
  1632
          argument and the first occurrence of <var>USN</var> from <var>dial device</var> as the <var>device
danieldanciu@330
  1633
          identifier</var> argument and the first occurrence of <var>CACHE-CONTROL</var> from <var>dial device</var>
danieldanciu@330
  1634
          (minus the leading string of <code>max-age=</code>) as the <var>device expiry</var> argument.
danieldanciu@330
  1635
          </li>
danieldanciu@330
  1636
        </ol>
danieldanciu@330
  1637
        <p>
richt@332
  1638
          The rule for <dfn>obtaining a DIAL Device Description File</dfn> is the process of obtaining the contents of
danieldanciu@330
  1639
          a standard UPnP Device Description [[!UPNP-DEVICEARCH11]] from a URL-based resource. This rule takes three
danieldanciu@330
  1640
          arguments - <var>device descriptor URL</var>, <var>device identifier</var> and <var>device expiry</var> - and
danieldanciu@330
  1641
          when called the user agent MUST run the following steps:
danieldanciu@330
  1642
        </p>
danieldanciu@330
  1643
        <ol class="rule">
danieldanciu@330
  1644
          <li>Let <var>device descriptor file</var> contain the contents of the file located at the URL provided in
danieldanciu@330
  1645
          <var>device descriptor URL</var> obtained according to the rules defined in 'Section 2.11: Retrieving a
danieldanciu@330
  1646
          description using HTTP' in [[!UPNP-DEVICEARCH11]].
danieldanciu@330
  1647
          </li>
danieldanciu@330
  1648
          <li>Let <var>application url</var> be the value of the first occurrence of the <code>Application-URL</code>
richt@371
  1649
          response header field obtained according to the rules defined in 'Section 5.4: Device Description Response'
richt@371
  1650
          in [<a href="https://sites.google.com/a/dial-multiscreen.org/dial/dial-protocol-specification">DIAL</a>]
danieldanciu@330
  1651
          </li>
danieldanciu@330
  1652
          <li>If the value provided in <var>device descriptor URL</var> cannot be resolved as a reachable URL on the
richt@371
  1653
          current network or the <var>device descriptor file</var> remains empty or <var>application url</var> is
richt@371
  1654
          undefined then it is invalid and the <a>user agent</a> MUST abort any remaining steps and return.
danieldanciu@330
  1655
          </li>
danieldanciu@330
  1656
          <li>Run the following steps to add the newly discovered DIAL service:
danieldanciu@330
  1657
            <ol class="rule">
danieldanciu@330
  1658
              <li>Let <var>network service record</var> be a new Object consisting of the following empty properties:
danieldanciu@330
  1659
              <code>id</code>, <code>deviceId</code>, <code>name</code>, <code>type</code>, <code>url</code>,
danieldanciu@330
  1660
              <code>expiryTimestamp</code>.
danieldanciu@330
  1661
              </li>
danieldanciu@330
  1662
              <li>Set <var>network service record</var>'s <code>id</code> property to the first occurrence of the
danieldanciu@330
  1663
              <code>&lt;UDN&gt;</code> element in the <var>descriptor file</var> prefixed with the <code>dial:</code>
danieldanciu@330
  1664
              string constant
danieldanciu@330
  1665
              </li>
danieldanciu@330
  1666
              <li>Set <var>network service record</var>'s <code>deviceId</code> property to the value of <var>device
danieldanciu@330
  1667
              identifier</var>.
danieldanciu@330
  1668
              </li>
danieldanciu@330
  1669
              <li>Set <var>network service record</var>'s <code>name</code> property to the string value of the first
danieldanciu@330
  1670
              occurrence of the <code>&lt;friendlyName&gt;</code> element in the <var>descriptor file</var>.
danieldanciu@330
  1671
              </li>
danieldanciu@330
  1672
              <li>Set <var>network service record</var>'s <code>type</code> property to <var>dial search target</var>.
danieldanciu@330
  1673
              </li>
richt@371
  1674
              <li>Set <var>network service record</var>'s <code>url</code> property to the string value of the
richt@371
  1675
              <var>application url</var>.
danieldanciu@330
  1676
              </li>
danieldanciu@330
  1677
              <li>Set <var>network service record</var>'s <code>expiryTimestamp</code> property to the value of the
danieldanciu@330
  1678
              current date, in UTC timestamp format, plus the value of <var>device expiry</var>.
danieldanciu@330
  1679
              </li>
danieldanciu@330
  1680
              <li>Run the general rule for <a>adding an available service</a>, passing in the current <var>network
danieldanciu@330
  1681
              service record</var> as the only argument.
danieldanciu@330
  1682
              </li>
danieldanciu@330
  1683
            </ol>
danieldanciu@330
  1684
          </li>
danieldanciu@330
  1685
        </ol>
danieldanciu@330
  1686
      </section>
danieldanciu@330
  1687
      <section>
richt@239
  1688
        <h3>
richt@239
  1689
          Network Topology Monitoring
richt@239
  1690
        </h3>
richt@239
  1691
        <div>
richt@180
  1692
          <p>
richt@376
  1693
            When the <a>user agent</a> detects that the user has dropped from a connected network then, for each
richt@377
  1694
            <var>existing service record</var> in the <a>list of available service records</a> discovered via that
richt@377
  1695
            network connection, the <a>user agent</a> MUST run the general rule for <a>removing an available
richt@377
  1696
            service</a> passing in each <var>existing service record</var>'s <code>id</code> property as the only
richt@377
  1697
            argument for each call.
richt@180
  1698
          </p>
richt@180
  1699
          <p>
richt@239
  1700
            When the <a>user agent</a> detects that the user has connected to a new network or reconnected to an
richt@250
  1701
            existing network, then it SHOULD restart its discovery mechanisms as defined in the <a href=
richt@250
  1702
            "#service-discovery">Service Discovery</a> section of this specification, maintaining the existing <a>list
richt@250
  1703
            of active service managers</a> currently in use.
richt@180
  1704
          </p>
richt@239
  1705
        </div>
richt@180
  1706
      </section>
richt@239
  1707
    </section>
richt@239
  1708
    <section>
richt@239
  1709
      <h3>
richt@239
  1710
        Events Summary
richt@239
  1711
      </h3>
richt@191
  1712
      <p>
richt@239
  1713
        The following events are dispatched on the <a href="#networkservices"><code>NetworkServices</code></a> and/or
richt@239
  1714
        <a href="#networkservice"><code>NetworkService</code></a> objects:
richt@191
  1715
      </p>
richt@243
  1716
      <table border="1">
richt@180
  1717
        <thead>
richt@180
  1718
          <tr>
richt@180
  1719
            <th>
richt@239
  1720
              <span>Event name</span>
richt@238
  1721
            </th>
richt@238
  1722
            <th>
richt@238
  1723
              <span>Interface</span>
richt@238
  1724
            </th>
richt@238
  1725
            <th>
richt@238
  1726
              <span>Dispatched when...</span>
richt@238
  1727
            </th>
richt@238
  1728
          </tr>
richt@238
  1729
        </thead>
richt@238
  1730
        <tbody>
richt@238
  1731
          <tr>
richt@238
  1732
            <td>
richt@239
  1733
              <dfn id="event-serviceavailable"><code>serviceavailable</code></dfn>
richt@238
  1734
            </td>
richt@238
  1735
            <td>
richt@239
  1736
              <a href="http://dvcs.w3.org/hg/domcore/raw-file/tip/Overview.html#event"
richt@239
  1737
                  class="externalDFN"><code>Event</code></a>
richt@238
  1738
            </td>
richt@238
  1739
            <td>
richt@387
  1740
              When a <a>new service</a> that matches one of the <a>requested type tokens</a> is found in the current
richt@387
  1741
              network.
richt@238
  1742
            </td>
richt@238
  1743
          </tr>
richt@238
  1744
          <tr>
richt@238
  1745
            <td>
richt@239
  1746
              <dfn id="event-serviceunavailable"><code>serviceunavailable</code></dfn>
richt@238
  1747
            </td>
richt@238
  1748
            <td>
richt@239
  1749
              <a href="http://dvcs.w3.org/hg/domcore/raw-file/tip/Overview.html#event"
richt@239
  1750
                  class="externalDFN"><code>Event</code></a>
richt@238
  1751
            </td>
richt@238
  1752
            <td>
richt@387
  1753
              When an <a>existing service</a> that matches one of the <a>requested type tokens</a> gracefully leaves or
richt@239
  1754
              expires from the current network.
richt@238
  1755
            </td>
richt@238
  1756
          </tr>
richt@238
  1757
          <tr>
richt@238
  1758
            <td>
richt@239
  1759
              <dfn id="event-serviceonline"><code>serviceonline</code></dfn>
richt@238
  1760
            </td>
richt@238
  1761
            <td>
richt@239
  1762
              <a href="http://dvcs.w3.org/hg/domcore/raw-file/tip/Overview.html#event"
richt@239
  1763
                  class="externalDFN"><code>Event</code></a>
richt@238
  1764
            </td>
richt@238
  1765
            <td>
richt@387
  1766
              When a <a>current service</a> renews its service registration within the current network.
richt@238
  1767
            </td>
richt@238
  1768
          </tr>
richt@238
  1769
          <tr>
richt@238
  1770
            <td>
richt@239
  1771
              <dfn id="event-serviceoffline"><code>serviceoffline</code></dfn>
richt@238
  1772
            </td>
richt@238
  1773
            <td>
richt@239
  1774
              <a href="http://dvcs.w3.org/hg/domcore/raw-file/tip/Overview.html#event"
richt@239
  1775
                  class="externalDFN"><code>Event</code></a>
richt@238
  1776
            </td>
richt@238
  1777
            <td>
richt@387
  1778
              When a <a>current service</a> gracefully leaves or otherwise expires from the current network.
richt@238
  1779
            </td>
richt@238
  1780
          </tr>
richt@238
  1781
          <tr>
richt@238
  1782
            <td>
richt@239
  1783
              <dfn id="event-notify"><code>notify</code></dfn>
richt@238
  1784
            </td>
richt@238
  1785
            <td>
richt@239
  1786
              <a href="http://dvcs.w3.org/hg/domcore/raw-file/tip/Overview.html#event"
richt@239
  1787
                  class="externalDFN"><code>Event</code></a>
richt@238
  1788
            </td>
richt@238
  1789
            <td>
richt@239
  1790
              When a valid UPnP Events Subscription Message is received on a <a>user-agent generated callback url</a>
richt@387
  1791
              for a <a>current service</a>. This event never fires for Zeroconf-based services.
richt@238
  1792
            </td>
richt@238
  1793
          </tr>
richt@238
  1794
        </tbody>
richt@238
  1795
      </table>
richt@239
  1796
    </section>
richt@239
  1797
    <section>
richt@239
  1798
      <h3>
richt@239
  1799
        Garbage collection
richt@239
  1800
      </h3>
richt@180
  1801
      <p>
richt@441
  1802
        There is an <dfn>implied strong reference</dfn> from any IDL attribute in this API that returns a pre-existing
richt@441
  1803
        object to that object.
richt@441
  1804
      </p>
richt@441
  1805
      <p class="note">
richt@441
  1806
        For example, if a <a><code>NetworkServices</code></a> object has one or more <a>indexed properties</a> attached
richt@441
  1807
        to it then there is a strong reference from that <a><code>NetworkServices</code></a> object toward each of its
richt@441
  1808
        <a>indexed properties</a>.
richt@250
  1809
      </p>
richt@250
  1810
      <p>
richt@441
  1811
        If a <a>user agent</a> is to <dfn>make disappear</dfn> a <a><code>NetworkServices</code></a> object (this
richt@441
  1812
        happens when a <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/dom.html#document"
richt@441
  1813
           class="externalDFN"><code>Document</code></a> object goes away), the <a>user agent</a> MUST remove this
richt@441
  1814
           object from the <a>list of active service managers</a> and remove the <a href=
richt@441
  1815
           "#dom-networkservice-url"><code>url</code></a> of each of its <a>indexed properties</a> from the <a>entry
richt@441
  1816
           script origin's URL whitelist</a>.
richt@180
  1817
      </p>
richt@239
  1818
    </section>
richt@180
  1819
    <section>
richt@239
  1820
      <h3>
richt@239
  1821
        Use Cases and Requirements
richt@239
  1822
      </h3>
richt@239
  1823
      <p>
richt@239
  1824
        This section covers what the requirements are for this API, as well as illustrates some use cases.
richt@239
  1825
      </p>
richt@180
  1826
      <ul class="rule">
richt@239
  1827
        <li>Once a user has given permission, user agents should provide the ability for Web pages to communicate
richt@239
  1828
        directly with a Local-networked Service.
richt@239
  1829
          <ul class="rule">
richt@239
  1830
            <li>Example: A web-based TV remote control. A Web page wants to control the current user's TV, changing the
richt@239
  1831
            programming shown or increasing/decreasing/muting the volume of the Local-networked Device. The Web page
richt@239
  1832
            requests a service type that is known to be implemented by television sets to which it has the application
richt@239
  1833
            logic to communicate. Local devices providing the request service types are discovered and presented to the
richt@239
  1834
            user for authorization. The user selects one or more of the discovered television sets to be accessible to
richt@239
  1835
            the current Web page and then clicks 'Share'. The Web page can now communicate directly with the
richt@239
  1836
            user-authorized Local-networked services.
richt@180
  1837
            </li>
richt@239
  1838
          </ul>
richt@239
  1839
        </li>
richt@239
  1840
        <li>Web pages should be able to communicate with Local-networked Services using the messaging channel supported
richt@239
  1841
        by those Devices.
richt@239
  1842
          <ul class="rule">
richt@239
  1843
            <li>Example: A Web page advertises that it is capable of controlling multiple Home Media Servers. The user
richt@239
  1844
            can select their Home Media Server type from a drop-down list, at which point the Web page sends a request
richt@239
  1845
            to the user agent to connect with the associated service type of the Home Media Server. The Media Server
richt@239
  1846
            selected implements a Web Socket channel for bi-directional service communication and so the Web page opens
richt@239
  1847
            a web socket to the requested Media Server and can communicate as required via that appropriate channel.
richt@180
  1848
            </li>
richt@239
  1849
          </ul>
richt@239
  1850
        </li>
richt@239
  1851
        <li>Web pages should be able to communicate with Local-networked Services using the messaging format supported
richt@239
  1852
        by those Devices.
richt@239
  1853
          <ul class="rule">
richt@239
  1854
            <li>Example: A Web page advertises that it is capable of interacting with and controlling multiple types of
richt@239
  1855
            Home Media Server. The user can select their Home Media Server type from a drop-down list or known Media
richt@239
  1856
            Servers, at which point the Web page sends a request to the user agent to connect with the associated
richt@240
  1857
            service type (and, optionally, the associated event type) of the Home Media Server. The communication
richt@239
  1858
            protocols supported by Home Media Servers typically vary between UPnP, JSON-RPC, Protocol Buffers or other
richt@239
  1859
            messaging formats depending on the Home Media Server requested. The Web page is able to communicate with
richt@239
  1860
            the user-selected Home Media Server in the messaging format supported by that Device, which, in this
richt@239
  1861
            example is a simple key/value pair text format.
richt@180
  1862
            </li>
richt@239
  1863
          </ul>
richt@239
  1864
        </li>
richt@239
  1865
        <li>Web pages should not be able to communicate with Local-networked Services that have not been authorized by
richt@239
  1866
        the user thereby maintaining the user's privacy.
richt@239
  1867
          <ul class="rule">
richt@239
  1868
            <li>Example: A Web page requests access to one type of Local-networked service. The user authorizes access
richt@239
  1869
            to that particular service. Other services running on that same device, and on other devices within the
richt@239
  1870
            network, should not be accessible to the current Web page.
richt@180
  1871
            </li>
richt@239
  1872
          </ul>
richt@239
  1873
        </li>
richt@239
  1874
        <li>A user should be able to share one or more Local-networked Services based on a particular service type
richt@239
  1875
        request from a Web page.
richt@239
  1876
          <ul class="rule">
richt@239
  1877
            <li>Example: A Web page is capable of interacting with a specific profile of Local-networked Service. As
richt@239
  1878
            such, it makes a request to the user agent to access those services, of which multiple matches are found.
richt@239
  1879
            The user is capable of selecting one or more of the discovered services to share with the Web page. The Web
richt@239
  1880
            page can then implement a drag-and-drop interface for the user to drag specific actions on to one or more
richt@239
  1881
            of the authorized Local-networked Services.
richt@239
  1882
            </li>
richt@239
  1883
          </ul>
richt@239
  1884
        </li>
richt@239
  1885
        <li>User agents should provide an API exposed to script that exposes the features above. The user is notified
richt@239
  1886
        by UI anytime interaction with Local-networked Services is requested, giving the user full ability to cancel or
richt@239
  1887
        abort the transaction. The user selects the Local-networked Services to be connected to the current Web page,
richt@239
  1888
        and can cancel these at any time. No invocations to these APIs occur silently without user intervention.
richt@239
  1889
        </li>
richt@180
  1890
      </ul>
richt@180
  1891
    </section>
richt@239
  1892
    <section class="informative appendix">
richt@239
  1893
      <h3>
richt@239
  1894
        Examples
richt@239
  1895
      </h3>
richt@239
  1896
      <div class="example">
richt@239
  1897
        <p>
richt@239
  1898
          This sample code exposes a button. When clicked, this button is disabled and the user is prompted to offer a
richt@239
  1899
          network service. The user may also select multiple network services. When the user has authorized a network
richt@239
  1900
          service to be connected to the web page then the web page issues a simple command to get a list of all the
richt@239
  1901
          albums stored on the connected media player service.
richt@239
  1902
        </p>
richt@239
  1903
        <p>
richt@239
  1904
          The button is re-enabled only when the connected network service disconnects for whatever reason (the service
richt@239
  1905
          becomes unavailable on the network, the user disconnects from their current network or the user revokes
richt@239
  1906
          access to the service from the current web page). At this point the user can re-click the button to select a
richt@239
  1907
          new network service to connect to the web page and the above steps are repeated.
richt@239
  1908
        </p>
richt@239
  1909
        <p>
richt@239
  1910
          The provided service type identifier and service interaction used in this example is based on the
richt@239
  1911
          well-defined service type and messaging format supported by the <a href="http://xbmc.org/about/">XBMC Media
richt@239
  1912
          Server</a>.
richt@239
  1913
        </p>
richt@239
  1914
        <hr>
richt@239
  1915
        <pre class="highlight">
richt@239
  1916
&lt;input type="button" value="Start" onclick="start()" id="startBtn"/&gt;
richt@239
  1917
&lt;div id="debugconsole"&gt;&lt;/div&gt;
richt@180
  1918
richt@239
  1919
&lt;script&gt;
richt@180
  1920
 var startBtn = document.getElementById('startBtn'),
richt@180
  1921
     debug = document.getElementById('debugconsole');
richt@180
  1922
richt@180
  1923
 function start() {
richt@180
  1924
   if(navigator.getNetworkServices) {
richt@438
  1925
      navigator.getNetworkServices('zeroconf:_xbmc-jsonrpc._tcp').then(gotXBMCService).catch(error);
richt@180
  1926
      startBtn.disabled = true;
richt@180
  1927
   } else {
richt@191
  1928
      debug.innerHTML += "&lt;br&gt;Service Discovery not supported!";
richt@180
  1929
   }
richt@180
  1930
 }
richt@180
  1931
richt@180
  1932
 function gotXBMCService(services) {
richt@180
  1933
richt@180
  1934
// Listen for service disconnect messages
richt@180
  1935
richt@191
  1936
   services[0].addEventListener('serviceoffline', function ( e ) {
richt@239
  1937
       debug.innerHTML += "&lt;br&gt;" + services[0].name + " disconnected.";
richt@180
  1938
       startBtn.disabled = false;
richt@180
  1939
   }, false);
richt@180
  1940
richt@180
  1941
// Send a service message to get albums list (and process the service response)
richt@180
  1942
richt@180
  1943
   var svcXhr = new XMLHttpRequest();
richt@240
  1944
   svcXhr.open("POST", services[0].url + "/getAlbums"); // services[0].url and its sub-resources have been
richt@180
  1945
                                                        // whitelisted for cross-site XHR use in this
richt@180
  1946
                                                        // current browsing context.
richt@180
  1947
richt@180
  1948
   svcXhr.setRequestHeader('Content-Type', 'application/json-rpc');
richt@180
  1949
richt@180
  1950
   svcXhr.addEventListener('readystatechange', function ( response ) {
richt@180
  1951
     if( response.readyState != 4 || response.status != 200 )
richt@180
  1952
        return;
richt@239
  1953
     debug.innerHTML += "&lt;br&gt;" + services[0].name + " response received: ";
richt@180
  1954
     debug.textContent += JSON.parse(response.responseText);
richt@180
  1955
   }, false);
richt@180
  1956
richt@180
  1957
   var svcMsg = [
richt@180
  1958
     { "jsonrpc": "2.0", "method": "AudioLibrary.GetAlbums", "params": { "genreid": -1,
richt@180
  1959
         "artistid": -1, "start": -1, "end": -1 }, "id": "1" }
richt@180
  1960
   ];
richt@180
  1961
richt@180
  1962
   svcXhr.send(JSON.stringify(svcMsg));
richt@239
  1963
   debug.innerHTML += "&lt;br&gt;" + services[0].name + " request sent: ";
richt@180
  1964
   debug.textContent += JSON.stringify(svcMsg);
richt@180
  1965
richt@180
  1966
 }
richt@180
  1967
richt@180
  1968
 function error( err ) {
richt@239
  1969
   debug.innerHTML += "&lt;br&gt;An error occurred obtaining a local network service.";
richt@180
  1970
   startBtn.disabled = false;
richt@180
  1971
 }
richt@239
  1972
&lt;/script&gt;
richt@239
  1973
</pre>
richt@239
  1974
      </div>
richt@239
  1975
      <div class="example">
richt@239
  1976
        <p>
richt@239
  1977
          This sample exposes a drop-down list containing a number of common Home-based audio devices. When the user
richt@239
  1978
          selects an audio device from the list provided, they are prompted to authorize a network service based on the
richt@239
  1979
          service type requested. The user may also select multiple network services matching the selected service
richt@239
  1980
          type. In this example, the user selects their make as being <var>Sony</var> and their model as being
richt@239
  1981
          <var>Bravia S1000</var> from which the Web page can derive a service type
richt@239
  1982
          (<var>urn:schemas-upnp-org:service:RenderingControl:1</var>).<br>
richt@239
  1983
          <br>
richt@239
  1984
          Once the user has authorized the device, the web page sends a simple mute command according to the messaging
richt@239
  1985
          format supported by the device.
richt@239
  1986
        </p>
richt@239
  1987
        <hr>
richt@239
  1988
        <pre class="highlight">
richt@239
  1989
&lt;select name="make" id="make"&gt;
richt@180
  1990
  &lt;option selected="selected" disabled="disabled"&gt;Select make&lt;/option&gt;
richt@180
  1991
  &lt;option&gt;Sony&lt;/option&gt;
richt@180
  1992
  &lt;option&gt;Philips&lt;/option&gt;
richt@180
  1993
  &lt;option&gt;Alba&lt;/option&gt;
richt@180
  1994
&lt;/select&gt;
richt@180
  1995
&lt;select name="model" id="model"&gt;&lt;/select&gt;
richt@180
  1996
&lt;div id="debugconsole"&gt;&lt;/div&gt;
richt@180
  1997
richt@180
  1998
&lt;script&gt;
richt@180
  1999
  var debug = document.getElementById('debugconsole');
richt@180
  2000
richt@180
  2001
  var models = {
richt@180
  2002
    "Sony": [
richt@180
  2003
      {"name": "Bravia TV S1000", "type": "upnp", "service": "urn:schemas-upnp-org:service:RenderingControl:1" },
richt@180
  2004
      {"name": "Bravia TV S2000", "type": "zeroconf", "service": "_mediarenderer._http._tcp" },
richt@180
  2005
      {"name": "HiFi WD10", "type": "upnp", "service": "urn:schemas-upnp-org:service:RenderingControl:1" }
richt@180
  2006
    ],
richt@180
  2007
    "Philips": [ /* ... */ ],
richt@180
  2008
    "Alba": [ /* ... */ ]
richt@180
  2009
  };
richt@180
  2010
richt@180
  2011
  var makeEl = document.getElementById("make"),
richt@180
  2012
      modelEl = document.getElementById("model");
richt@180
  2013
richt@180
  2014
  makeEl.addEventListener('change', function() {
richt@180
  2015
    modelEl.innerHTML = ""; // reset
richt@180
  2016
    var defaultOption = document.createElement("option");
richt@180
  2017
    defaultOption.textContent = "Select model";
richt@180
  2018
    defaultOption.setAttribute("disabled", "disabled");
richt@180
  2019
    defaultOption.setAttribute("selected", "selected");
richt@180
  2020
    modelEl.appendChild(defaultOption);
richt@239
  2021
    for(var i = 0, l = models[makeEl.value].length; i &lt; l; i++) {
richt@180
  2022
      var option = document.createElement("option");
richt@180
  2023
      option.textContent = models[makeEl.value][i]["name"];
richt@180
  2024
      option.setAttribute("value", models[makeEl.value][i]["type"] + ":" + models[makeEl.value][i]["service"]);
richt@180
  2025
      modelEl.appendChild(option);
richt@180
  2026
    }
richt@180
  2027
  }, false);
richt@180
  2028
richt@180
  2029
  modelEl.addEventListener('change', function() {
richt@239
  2030
    if(navigator.getNetworkServices &amp;&amp;
richt@180
  2031
         modelEl.value == "upnp:urn:schemas-upnp-org:service:RenderingControl:1") {
richt@437
  2032
      var servicesPromise = navigator.getNetworkServices(modelEl.value).then(successCallback, errorCallback);
richt@180
  2033
    } else if (modelEl.value == "zeroconf:_mediarenderer._http._tcp") {
richt@180
  2034
      debug.innerHTML += "&lt;br&gt;Service type is not implemented by this application.";
richt@180
  2035
    } else {
richt@180
  2036
      debug.innerHTML += "&lt;br&gt;Service Discovery is not supported!";
richt@180
  2037
    }
richt@180
  2038
  }, false);
richt@180
  2039
&lt;/script&gt;
richt@180
  2040
richt@180
  2041
&lt;script&gt;
richt@180
  2042
  function successCallback( services ) {
richt@180
  2043
richt@191
  2044
  // Listen for service push notification messages
richt@180
  2045
richt@191
  2046
    services[0].addEventListener('notify', function ( msg ) {
richt@239
  2047
         debug.innerHTML += "&lt;br&gt;" + services[0].name + " event received: ";
richt@180
  2048
         debug.textContent += msg.data;
richt@180
  2049
    }, false);
richt@180
  2050
richt@180
  2051
 // Send a control signal to mute the service audio
richt@180
  2052
richt@180
  2053
    var svcXhr = new XMLHttpRequest();
richt@180
  2054
    svcXhr.open("POST", services[0].url); // services[0].url and its
richt@240
  2055
                                          // sub-resources have been whitelisted for
richt@180
  2056
                                          // cross-site XHR use in this current
richt@180
  2057
                                          // browsing context.
richt@180
  2058
richt@180
  2059
    svcXhr.setRequestHeader('SOAPAction', 'urn:schemas-upnp-org:service:RenderingControl:1#SetMute');
richt@180
  2060
    svcXhr.setRequestHeader('Content-Type', 'text/xml; charset="utf-8";');
richt@180
  2061
richt@180
  2062
    svcXhr.onreadystatechange = function ( response ) {
richt@180
  2063
      if( response.readyState != 4 || response.status != 200 )
richt@180
  2064
        return;
richt@180
  2065
      debug.innerHTML += "&lt;br&gt;" + services[0].name + " response received: ";
richt@180
  2066
      debug.textContent += response.responseXML;
richt@180
  2067
    }
richt@180
  2068
richt@180
  2069
    // Service messaging to mute the provided service
richt@180
  2070
    var svcMsg = '&lt;?xml version="1.0" encoding="utf-8"?&gt;' +
richt@180
  2071
                 '&lt;s:Envelope s:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/" ' +
richt@180
  2072
                   'xmlns:s="http://schemas.xmlsoap.org/soap/envelope/"&gt;' +
richt@180
  2073
                   '&lt;s:Body&gt;' +
richt@180
  2074
                     '&lt;u:SetMute xmlns:u="urn:schemas-upnp-org:service:RenderingControl:1"&gt;' +
richt@180
  2075
                       '&lt;InstanceID&gt;0&lt;/InstanceID&gt;' +
richt@180
  2076
                       '&lt;Channel&gt;Master&lt;/Channel&gt;' +
richt@180
  2077
                       '&lt;DesiredMute&gt;true&lt;/DesiredMute&gt;' +
richt@180
  2078
                     '&lt;/u:SetMute&gt;' +
richt@180
  2079
                   '&lt;/s:Body&gt;' +
richt@180
  2080
                 '&lt;/s:Envelope&gt;';
richt@180
  2081
richt@180
  2082
    svcXhr.send(svcMsg);
richt@180
  2083
    debug.innerHTML += "&lt;br&gt;" + services[0].name + " request sent: ";
richt@180
  2084
    debug.textContent += svcMsg;
richt@180
  2085
  }
richt@180
  2086
richt@180
  2087
  function errorCallback( error ) {
richt@447
  2088
    debug.innerHTML += "&lt;br&gt;An error occurred: " + error.name;
richt@180
  2089
  }
richt@239
  2090
&lt;/script&gt;
richt@239
  2091
</pre>
richt@239
  2092
      </div>
richt@239
  2093
    </section>
richt@180
  2094
    <section>
richt@239
  2095
      <h3>
richt@239
  2096
        Acknowledgements
richt@239
  2097
      </h3>
richt@239
  2098
      <p>
richt@239
  2099
        Thanks are expressed by the editor to the following individuals for their feedback on this specification to
richt@239
  2100
        date (in alphabetical order):<br>
richt@239
  2101
        <br>
richt@239
  2102
        Gar Bergstedt, Lars-Erik Bolstad, Cathy Chan, Hari G Kumar, Bob Lund, Giuseppe Pascale, Marcin Simonides,
richt@239
  2103
        Clarke Stevens, Christian Söderström, Mark Vickers.
richt@239
  2104
      </p>
richt@239
  2105
      <p>
richt@239
  2106
        Thanks are also expressed by the editor to the following organizations and groups for their support in
richt@239
  2107
        producing this specification to date (in alphabetical order):<br>
richt@239
  2108
        <br>
richt@239
  2109
        CableLabs, Opera Software ASA, W3C Device APIs Working Group, W3C Web and TV Interest Group.
richt@239
  2110
      </p>
richt@180
  2111
    </section>
richt@239
  2112
  </body>
richt@180
  2113
</html>