discovery-api/Overview.src.html
author Rich Tibbett <richt@opera.com>
Tue, 25 Sep 2012 12:48:42 +0200
changeset 230 3c13dc93cfb1
parent 216 5583626294f6
child 231 a0e6b501258d
permissions -rw-r--r--
Re-write of Section 7: Service Discovery according to feedback @ http://lists.w3.org/Archives/Public/public-device-apis/2012Aug/0017.html
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<!DOCTYPE html>
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<html>
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  <head>
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    <title>Networked Service Discovery and Messaging</title>
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    <meta http-equiv='Content-Type' content='text/html;charset=utf-8'/>
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          specStatus:   "ED",
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          //publishDate:  "2012-08-22",
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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: "WD",
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          previousPublishDate: "2012-08-07",
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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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              name:       "Clarke Stevens",
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              //url:      "",
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              company:    "CableLabs",
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              companyURL: "http://cablelabs.com/"
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            }
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          ],
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          noIDLIn:      true,
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          wg:           "Device APIs and Policy 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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          wgPatentURI:  "http://www.w3.org/2004/01/pp-impl/43696/status"
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    </style>
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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 <abbr title="Hypertext Transfer Protocol">HTTP</abbr>-based services
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        advertised via common discovery protocols within a user's 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
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        API.
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      </p>
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    </section>
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    <section class="informative">
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      <h3>Introduction</h3>
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      <p>To enable Web pages to connect and communicate with Local-networked Services provided over HTTP, this specification introduces the
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      <a href="#navigatornetworkservice"><code>NavigatorNetworkService</code></a> interface.</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 service type, known by developers and advertised by Local-networked Devices. User authorization, where the user connects the web page to one or more discovered services,
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         is expected before the web page is able to interact with any 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 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 Service Discovery mechanisms included in this recommendation, attempts to match
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      the requested service type to a discovered 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 the necessary information to communicate with the authorized Local-networked Service.
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          If the request fails then the Web page will receive an error callback containing an error code 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 Local-networked Service via the messaging format and appropriate channel inferred from the service type
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         authorized via the provided API.
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         The Web page, once connected, can also receive service-pushed events, in the messaging format supported by the Local-networked Device, if such event subscription functionality is provided by the
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         connected Local-networked Service.
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      </p>
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      <div class="example">
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       <p>Example of requesting a DNS-SD advertised service:</p>
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       <hr />
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       <pre class="highlight">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 < l; i++) console.log( services[i].name );
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}
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navigator.getNetworkServices('zeroconf:_boxee-jsonrpc._tcp', showServices);</pre>
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      </div>
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      <div class="example">
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        <p>Example of requesting a UPnP advertised service, also handling error conditions:</p>
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        <hr />
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        <pre class="highlight">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 < 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.code );
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}
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navigator.getNetworkServices('upnp:urn:schemas-upnp-org:service:ContentDirectory:1', showServices, error);</pre>
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      </div>
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      <div class="example">
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        <p>Example of requesting either a DNS-SD or UPnP advertised service:</p>
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        <hr />
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        <pre class="highlight">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 < 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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], showServices);</pre>
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      </div>
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      <p>For more detailed examples see the <a href="#examples">Examples</a> section.
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    </section>
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    <section
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     id='conformance'>
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     <p>Requirements phrased in the imperative as part of algorithms (such as "strip any leading space characters" or "return false and abort these steps") are to be interpreted with the
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     meaning of the key word ("must", "should", "may", etc) used in introducing the algorithm.</p>
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     <p>
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      Some conformance requirements are phrased as requirements on attributes, methods or objects. Such requirements 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 the end result is equivalent. (In particular, the algorithms defined in
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      this specification are intended to be 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 of service attacks, to guard against running out of memory, or to work
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      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 in development, or for performance reasons), user agents must act as if
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      they had no support for the feature whatsoever, and as if the feature was not mentioned in this specification. For example, if a particular feature is accessed via an attribute in a Web
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      IDL interface, the attribute itself would be omitted from the objects that implement that interface - leaving the attribute on the object but making it return null or throw an exception
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      is insufficient.
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     </p>
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      <section>
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         <h3>Dependencies</h3>
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         This specification relies on several other underlying specifications.
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         <dl>
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            <dt>HTML</dt>
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            <dd>Many fundamental concepts from HTML are used by this specification. [[!HTML5]]</dd>
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            <dt>WebIDL</dt>
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            <dd>The IDL blocks in this specification use the semantics of the WebIDL specification. [[!WEBIDL]]</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>Terminology</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 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 necessarily imply the existence of an actual <code>Document</code> object or of any
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         other <code>Node</code> 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 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 a string that begins with <code>upnp:</code> or <code>zeroconf:</code> followed by one or more characters 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, U+005E to U+007E.
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      </p>
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      <p></p>
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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="#dom-navigator-getnetworkservices"><code>getNetworkServices()</code></a> method will be matched against the services currently contained in the <a>list of available service records</a> according to the algorithms 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 agent</a> must generate and maintain for receiving HTTP NOTIFY requests from UPnP Event sources. It is only required when the user agent implements UPnP Service Discovery as defined in
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        this specification.
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      </p>
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    </section>
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    <section>
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     <h2>Requesting networked services</h2>
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<pre class="widl">[Supplemental, NoInterfaceObject]
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interface <dfn id="navigatornetworkservice">NavigatorNetworkService</dfn> {
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  // Obtain a Local-networked Service
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  void <a href="#dom-navigator-getnetworkservices">getNetworkServices</a>( in any type,
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                           in <a href="#navigatornetworkservicesuccesscallback">NavigatorNetworkServiceSuccessCallback</a> successCallback,
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                           in optional <a href="#navigatornetworkserviceerrorcallback">NavigatorNetworkServiceErrorCallback</a> errorCallback );
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};
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<a class="externalDFN" href="http://www.whatwg.org/specs/web-apps/current-work/complete/timers.html#navigator">Navigator</a> implements <a href="#navigatornetworkservice">NavigatorNetworkService</a>;
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[Callback=FunctionOnly, NoInterfaceObject]
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interface <dfn id="navigatornetworkservicesuccesscallback">NavigatorNetworkServiceSuccessCallback</dfn> {
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  void handleEvent( in <a href="#networkservices">NetworkServices</a> services );
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};
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[NoInterfaceObject]
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interface <dfn id="navigatornetworkserviceerror">NavigatorNetworkServiceError</dfn> {
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  const unsigned short <a href="#dom-navigatornetworkserviceerror-permission_denied">PERMISSION_DENIED_ERR</a> = 1;
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  const unsigned short <a href="#dom-navigatornetworkserviceerror-unknown_type_prefix">UNKNOWN_TYPE_PREFIX_ERR</a> = 2;
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  readonly attribute unsigned short <a href="#dom-navigatornetworkserviceerror-code">code</a>;
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};
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[Callback=FunctionOnly, NoInterfaceObject]
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interface <dfn id="navigatornetworkserviceerrorcallback">NavigatorNetworkServiceErrorCallback</dfn> {
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  void handleEvent( in <a href="#navigatornetworkserviceerror">NavigatorNetworkServiceError</a> error );
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};
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</pre>
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  <section>
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   <h2>Methods</h2>
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      <dl class="domintro">
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        <dt>
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          <var title="">window</var>
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           .
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          <code title="dom-navigator">
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            <a href="http://www.whatwg.org/specs/web-apps/current-work/complete/timers.html#navigator">navigator</a>
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          </code>
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           .
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          <code title="dom-navigator-getNetworkServices">
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            <a href="#dom-navigator-getnetworkservices">getNetworkServices</a>
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          </code>
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          (
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          <var title="">type</var>
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          ,
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          <var title="">successCallback</var>
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           [,
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          <var title="">errorCallback</var>
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           ] )
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        </dt>
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        <dd>
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          <p>Prompts the user to select one or more discovered network services that have advertised support for the requested service type.</p>
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          <p>
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            The
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            <var title="">type</var>
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             argument contains one or more <a>valid service type</a> tokens that the web page would like to interact with.
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          </p>
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          <p>
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            If the user accepts, the
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            <var title="">successCallback</var>
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             is
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          invoked, with one or more
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            <code>
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              <a href="#networkservice"><code>NetworkService</code></a>
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            </code>
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             objects as
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          its argument.
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          </p>
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          <p>
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            If the user declines, the
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            <var title="">errorCallback</var>
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             (if
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          any) is invoked.
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          </p>
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        </dd>
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      </dl>
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       <div>
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          <p>
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            When the <dfn id="dom-navigator-getnetworkservices" title="dom-navigator-getnetworkservices"><code>getNetworkServices(type, successCallback[, errorCallback])</code></dfn> method is called, the <a>user agent</a> MUST run the following steps:
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          </p>
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          <ol class="rule">
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            <li>
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              Let <var>requested control types</var> be initially set to an empty array.
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            </li>
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            <li>
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               If <var>type</var> is an array consisting of one or more <a>valid service type</a> tokens, then let <var>requested control types</var> by the value of <var>type</var>, removing any non-<a>valid service type</a> tokens from the resulting array.
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            </li>
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            <li>
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               If <var>type</var> is a string consisting of one <a>valid service type</a> token, then let <var>requested control types</var> be an array containing one item with a value of <var>type</var>.
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            </li>
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            <li>
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               If <var>requested control types</var> is an array that contains at least one or more <a title="valid service type">valid service type</a> tokens then continue to the step labeled <em>process</em> below. Otherwise, the <a>user agent</a> MUST <a href="http://www.whatwg.org/specs/web-apps/current-work/complete/webappapis.html#queue-a-task" class="externalDFN">queue a task</a> to invoke <var>errorCallback</var>, if it is provided and is an object of type <code>Function</code>, with a new <a href="#navigatornetworkserviceerror"><code>NavigatorNetworkServiceError</code></a> object whose
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                 <a href="#dom-navigatornetworkserviceerror-code"><code>code</code></a> attribute has the numeric value 2
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                  (<a href="#dom-navigatornetworkserviceerror-unknown_type_prefix"><code>UNKNOWN_TYPE_PREFIX_ERR</code></a>) as its argument,
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                   abort any remaining steps and return.
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            </li>
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            <li>
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               <em>Process</em>: Let <var>services found</var> be an empty array.
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            </li>
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            <li>
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               For each <var>available service</var> in the <a>list of available service records</a> run the following steps:
richt@180
   346
               <ol class="rule">
richt@180
   347
                  <li>
richt@180
   348
                    For each <var>requested control type</var> in <var>requested control types</var>: If <var>available service</var>'s <code>type</code> attribute equals the <var>requested control type</var> then let <var>matched service</var> equal the value of <var>available service</var> and continue at the step labeled <var>attach</var> below.
richt@180
   349
                  </li>
richt@180
   350
                  <li>
richt@180
   351
                     Continue at the next <var>available service</var>.
richt@180
   352
                  </li>
richt@180
   353
                  <li>
richt@180
   354
                     <em>Attach</em>: If <var>matched service</var> is not empty then run the following steps:
richt@180
   355
richt@180
   356
                     <ol class="rule">
richt@180
   357
                        <li>
richt@180
   358
                           Let <var>new service object</var> be a new <a href="#networkservice"><code>NetworkService</code></a> object, mapping the parameters of
richt@180
   359
                     <var>matched service</var> to this new object where possible.
richt@180
   360
                        </li>
richt@180
   361
                        <li>
richt@180
   362
                           Append <var>new service object</var> to the <var>services found</var> array.
richt@180
   363
                        </li>
richt@180
   364
                     </ol>
richt@180
   365
                  </li>
richt@180
   366
               </ol>
richt@180
   367
            </li>
richt@180
   368
richt@180
   369
            <li>
richt@180
   370
               If <var>services found</var> is an empty array, then the <a>user agent</a> MUST <a href="http://www.whatwg.org/specs/web-apps/current-work/complete/webappapis.html#queue-a-task" class="externalDFN">queue a task</a> to invoke <var>errorCallback</var>, if it is provided and is an object of type <code>Function</code>, with a new <a href="#navigatornetworkserviceerror"><code>NavigatorNetworkServiceError</code></a> object whose
richt@180
   371
                 <a href="#dom-navigatornetworkserviceerror-code"><code>code</code></a> attribute has the numeric value 1
richt@180
   372
                 (<a href="#dom-navigatornetworkserviceerror-permission_denied"><code>PERMISSION_DENIED_ERR</code></a>) as its argument, abort any remaining steps and return.
richt@180
   373
            </li>
richt@180
   374
richt@180
   375
            <li>
richt@180
   376
               Return, and run the remaining steps asynchronously.
richt@180
   377
            </li>
richt@180
   378
richt@180
   379
            <li>
richt@180
   380
               Optionally, e.g. based on a previously-established user preference, for security reasons, or due to platform limitations, the <a>user agent</a> MAY <a href="http://www.whatwg.org/specs/web-apps/current-work/complete/webappapis.html#queue-a-task" class="externalDFN">queue a task</a> to invoke <var>errorCallback</var>, if it is provided and is an object of type <code>Function</code>, with a new <a href="#navigatornetworkserviceerror"><code>NavigatorNetworkServiceError</code></a> object whose
richt@180
   381
                 <a href="#dom-navigatornetworkserviceerror-code"><code>code</code></a> attribute has the numeric value 1
richt@180
   382
                 (<a href="#dom-navigatornetworkserviceerror-permission_denied"><code>PERMISSION_DENIED_ERR</code></a>) as its argument, abort any remaining steps and return.
richt@180
   383
            </li>
richt@180
   384
richt@180
   385
            <li>
richt@180
   386
                  The <a>user agent</a> MUST prompt the user in a user-agent-specific manner for permission to provide the
richt@180
   387
                  <a href="http://www.whatwg.org/specs/web-apps/current-work/complete/browsers.html#entry-script" class="externalDFN">entry script</a>'s
richt@180
   388
                  <a href="http://www.whatwg.org/specs/web-apps/current-work/complete/origin-0.html#origin" class="externalDFN">origin</a> with an array of
richt@180
   389
                  <a href="#networkservice"><code>NetworkService</code></a> objects representing the user-authorized subset of <var>services found</var>.
richt@180
   390
richt@180
   391
               <p>
richt@180
   392
                  If the user grants permission to access one or more networked services then the <a>user agent</a> SHOULD include an
richt@180
   393
                  "ongoing local-network communication" indicator.
richt@180
   394
               </p>
richt@180
   395
richt@180
   396
               <p>If the user denies permission, then the <a>user agent</a> MUST <a href="http://www.whatwg.org/specs/web-apps/current-work/complete/webappapis.html#queue-a-task" class="externalDFN">queue a task</a> to invoke <var>errorCallback</var>, if it is provided and is an object of type <code>Function</code>, with a new <a href="#navigatornetworkserviceerror"><code>NavigatorNetworkServiceError</code></a> object whose
richt@180
   397
                <a href="#dom-navigatornetworkserviceerror-code"><code>code</code></a> attribute has the numeric value 1
richt@180
   398
                (<a href="#dom-navigatornetworkserviceerror-permission_denied"><code>PERMISSION_DENIED_ERR</code></a>) as its argument, abort any remaining steps and return.
richt@180
   399
              </p>
richt@180
   400
richt@180
   401
              <p>
richt@180
   402
                If the user never responds, this algorithm stalls on this step.
richt@180
   403
              </p>
richt@180
   404
richt@180
   405
            </li>
richt@180
   406
richt@180
   407
            <li>
richt@180
   408
               Let <var>services</var> be the array of one or more <a href="#networkservice"><code>NetworkService</code></a> objects for which the user granted permission.
richt@180
   409
            </li>
richt@180
   410
richt@180
   411
            <li>
richt@180
   412
               For each Object <var>service</var> in <var>services</var>, run the following substeps:
richt@180
   413
richt@180
   414
               <ol class="rule">
richt@180
   415
                  <li>
robin@185
   416
                     Add the <var>service</var>'s <code>url</code> parameter to the <a>entry script origin's <abbr title="Uniform Resource Locator">URL</abbr> whitelist</a>.
richt@180
   417
                  </li>
richt@180
   418
                  <li>
richt@191
   419
                    If <var>service</var>'s <code>type</code> parameter begins with the DOMString &quot;<code>upnp:</code>&quot; and the <var>service</var>'s <code>eventsUrl</code> parameter is not empty then <a>setup a UPnP Events Subscription</a> for <var>service</var>.
richt@180
   420
                  </li>
richt@180
   421
               </ol>
richt@180
   422
            </li>
richt@180
   423
richt@180
   424
            <li>
richt@180
   425
               Let <var>services manager</var> be a new <a href="#networkservices"><code>NetworkServices</code></a> object.
richt@180
   426
            </li>
richt@180
   427
richt@180
   428
            <li>
richt@191
   429
               Set <var>services manager</var>'s <a href="#dom-networkservices-servicesavailable"><code>servicesAvailable</code></a> attribute to the length of <var>services</var>.
richt@180
   430
            </li>
richt@180
   431
richt@180
   432
            <li>
richt@230
   433
              Add the set of <var>services</var> to the <a>list of authorized service records</a> internally against the newly created <var>services manager</var> object.
richt@180
   434
            </li>
richt@180
   435
richt@180
   436
            <li>
richt@180
   437
               The <a>user agent</a> MUST <a href="http://www.whatwg.org/specs/web-apps/current-work/complete/webappapis.html#queue-a-task" class="externalDFN">queue a task</a> to invoke <var>successCallback</var> with
richt@180
   438
               <var>services manager</var> as its argument.
richt@180
   439
            </li>
richt@180
   440
richt@180
   441
          </ol>
richt@180
   442
richt@180
   443
          <p>
richt@180
   444
            The <a href="http://www.whatwg.org/specs/web-apps/current-work/complete/webappapis.html#task-source" class="externalDFN">task source</a> for these
richt@180
   445
            <a href="http://www.whatwg.org/specs/web-apps/current-work/complete/webappapis.html#concept-task" class="externalDFN">tasks</a> is the
richt@180
   446
            <a href="http://www.whatwg.org/specs/web-apps/current-work/complete/webappapis.html#user-interaction-task-source" class="externalDFN">user interaction task source</a>.
richt@180
   447
          </p>
richt@180
   448
richt@180
   449
          <p>
richt@180
   450
            When a <a href="#networkservice"><code>NetworkService</code></a> object is provided to a Web page, the <a>user agent</a> MUST add the <code>url</code> property
richt@180
   451
             to the <dfn>entry script origin's URL whitelist</dfn>. This list enables the
richt@180
   452
            Web page to override and initiate cross-site resource requests towards these URLs, and any sub-resources of these URLs, within the current
richt@180
   453
            <a href="http://www.whatwg.org/specs/web-apps/current-work/complete/browsers.html#entry-script" class="externalDFN">entry script</a>'s
richt@180
   454
            <a href="http://www.whatwg.org/specs/web-apps/current-work/complete/origin-0.html#origin" class="externalDFN">origin</a> via various existing mechanisms (e.g. Web Sockets, Server-Sent Events,
richt@180
   455
            Web Messaging, XMLHttpRequest).
richt@180
   456
         </p>
richt@180
   457
richt@180
   458
         <p>
richt@180
   459
            If the user navigates away from the current browsing context, the <a>user agent</a> MUST remove all previously whitelisted urls from the <a>entry script origin's URL whitelist</a>.
richt@180
   460
            There is no persistence to network service selections provided to a web page. It is not possible to access a previously white-listed networked service without the necessary user authorization in all of the following cases:
richt@180
   461
            <ul>
richt@180
   462
              <li>If the current script is reloaded at any point in the same or different window.</li>
richt@180
   463
              <li>if the current script reinvokes the <a href="#dom-navigator-getnetworkservices"><code>getNetworkServices()</code></a> method at any point in its execution.</li>
richt@180
   464
              <li>If the user navigates forward or back in their history to reload the current page.</li>
richt@180
   465
              <li>If a script is running in a different origin.</li>
richt@180
   466
            </ul>
richt@180
   467
         </p>
richt@180
   468
richt@180
   469
      </div>
richt@180
   470
      </section>
richt@180
   471
richt@180
   472
      <section>
richt@180
   473
         <h3>Error Handling</h3>
richt@180
   474
richt@180
   475
      <dl class="domintro">
richt@180
   476
        <dt>
richt@180
   477
          <var title="">error</var>
richt@180
   478
           .
richt@180
   479
          <code title="dom-NavigatorNetworkServiceError-code">
richt@180
   480
            <a href="#dom-navigatornetworkserviceerror-code">code</a>
richt@180
   481
          </code>
richt@180
   482
        </dt>
richt@180
   483
        <dd>
richt@180
   484
          <p>
richt@180
   485
            Returns the current error's error code. At the current time, this may be <code>1</code> or <code>2</code>, for which the
richt@180
   486
            corresponding error constants
richt@180
   487
            <a href="#dom-navigatornetworkserviceerror-permission_denied"><code>PERMISSION_DENIED_ERR</code></a> and
richt@180
   488
            <a href="#dom-navigatornetworkserviceerror-unknown_type_prefix"><code>UNKNOWN_TYPE_PREFIX_ERR</code></a> are defined.
richt@180
   489
          </p>
richt@180
   490
        </dd>
richt@180
   491
      </dl>
richt@180
   492
richt@180
   493
         <p>
richt@180
   494
            The <dfn id="dom-navigatornetworkserviceerror-code" title="dom-navigatornetworkserviceerror-code"><code>code</code></dfn> attribute of a
richt@180
   495
            <a href="#navigatornetworkserviceerror"><code>NavigatorNetworkServiceError</code></a> object MUST return the code for the error, which will be one of the following:
richt@180
   496
         </p>
richt@180
   497
richt@180
   498
         <dl>
richt@180
   499
            <dt>
richt@180
   500
               <dfn id="dom-navigatornetworkserviceerror-permission_denied" title="dom-navigatornetworkserviceerror-permission_denied"><code>PERMISSION_DENIED_ERR</code></dfn> (numeric value 1)
richt@180
   501
            </dt>
richt@180
   502
            <dd>
richt@194
   503
               The user or user agent denied the page permission to access any services.
richt@180
   504
            </dd>
richt@180
   505
            <dt>
richt@180
   506
               <dfn id="dom-navigatornetworkserviceerror-unknown_type_prefix" title="dom-navigatornetworkserviceerror-unknown_type_prefix"><code>UNKNOWN_TYPE_PREFIX_ERR</code></dfn> (numeric value 2)
richt@180
   507
            </dt>
richt@180
   508
            <dd>
richt@180
   509
               No <a>valid service type</a> tokens were provided in the method invocation.
richt@180
   510
            </dd>
richt@180
   511
         </dl>
richt@180
   512
richt@180
   513
      </section>
richt@180
   514
richt@180
   515
      </section>
richt@180
   516
      <section>
richt@180
   517
      <h2>Obtaining networked services</h2>
richt@180
   518
richt@180
   519
      <p>
richt@180
   520
         The <a href="#networkservices"><code>NetworkServices</code></a> interface is the top-level response object from a call to <a href="#dom-navigator-getnetworkservices"><code>getNetworkServices()</code></a> and provides access to a set of user-authorized <a href="#networkservice"><code>NetworkService</code></a> objects for the given request.
richt@180
   521
      </p>
richt@180
   522
richt@180
   523
<pre class="widl">
richt@180
   524
[NoInterfaceObject]
richt@180
   525
interface <dfn id="networkservices">NetworkServices</dfn> {
richt@180
   526
  readonly attribute unsigned long    <a href="#dom-networkservices-length">length</a>;
richt@180
   527
  getter <a href="#networkservice">NetworkService</a> (unsigned long index);
richt@180
   528
  <a href="#networkservice">NetworkService</a>? <a href="#dom-networkservices-getservicebyid">getServiceById</a>(DOMString id);
richt@180
   529
richt@180
   530
  readonly attribute unsigned long    <a href="#dom-networkservices-servicesavailable">servicesAvailable</a>;
richt@180
   531
richt@180
   532
  // event handler attributes
richt@180
   533
           attribute <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/webappapis.html#eventhandler" class="externalDFN">EventHandler</a>     <a href="#dom-networkservices-onserviceavailable">onserviceavailable</a>;
richt@180
   534
           attribute <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/webappapis.html#eventhandler" class="externalDFN">EventHandler</a>     <a href="#dom-networkservices-onserviceunavailable">onserviceunavailable</a>;
richt@180
   535
richt@180
   536
};
richt@180
   537
richt@180
   538
<a href="#networkservices">NetworkServices</a> implements <a href="http://dvcs.w3.org/hg/domcore/raw-file/tip/Overview.html#interface-eventtarget" class="externalDFN">EventTarget</a>;
richt@180
   539
</pre>
richt@180
   540
richt@180
   541
      <section>
richt@180
   542
      <h2>Attributes</h2>
richt@180
   543
richt@180
   544
        <dl class="domintro">
richt@180
   545
          <dt>
richt@180
   546
            <code title="dom-networkservices-length">
richt@180
   547
              <a href="#dom-networkservices-length">length</a>
richt@180
   548
            </code>
richt@180
   549
          </dt>
richt@180
   550
          <dd>
richt@180
   551
            <p>
richt@230
   552
              Returns the current number of services belonging in the respective object's <a>list of authorized service records</a>.
richt@180
   553
            </p>
richt@180
   554
          </dd>
richt@180
   555
          <dt>
richt@180
   556
            <code title="dom-networkservices-servicesavailable">
richt@180
   557
              <a href="#dom-networkservices-servicesavailable">servicesAvailable</a>
richt@180
   558
            </code>
richt@180
   559
          </dt>
richt@180
   560
          <dd>
richt@180
   561
            <p>
richt@180
   562
              Returns the current number of services matching one of the app-requested <a>valid service type</a> tokens that are actively available within the user's current network.
richt@180
   563
            </p>
richt@180
   564
          </dd>
richt@180
   565
        </dl>
richt@180
   566
richt@180
   567
        <div>
richt@180
   568
           <p>
richt@230
   569
              The <dfn id="dom-networkservices-length"><code>length</code></dfn> attribute MUST return the number of services represented in the object's corresponding <a>list of authorized service records</a> at the time of getting.
richt@180
   570
           </p>
richt@180
   571
richt@180
   572
           <p>
richt@180
   573
              The <dfn id="dom-networkservices-servicesavailable"><code>servicesAvailable</code></dfn> attribute MUST return the number of services available in the
richt@180
   574
              user's network that match the <a>valid service type</a> that was initially used to create the current <a href="#networkservices"><code>NetworkServices</code></a> object.
richt@180
   575
           </p>
richt@180
   576
richt@180
   577
           <p>
richt@191
   578
             When a previously unknown instance of a networked service matching one of the requested <a href="#dfn-valid-service-type">valid service types</a> becomes available on the user's current network, the <a>user agent</a> MUST increment the <a href="#dom-networkservices-servicesavailable"><code>servicesAvailable</code></a> attribute by <code>1</code> and then
richt@191
   579
             <a href="http://www.whatwg.org/specs/web-apps/current-work/complete/webappapis.html#queue-a-task" class="externalDFN">queue a task</a>
richt@191
   580
             to dispatch a newly created event with the name <code>serviceavailable</code> that uses the <code>Event</code> interface, which does
richt@191
   581
             not bubble, is not cancellable, and has no default action, at the current <a href="#networkservices"><code>NetworkServices</code></a>
richt@191
   582
             object.
richt@180
   583
           </p>
richt@180
   584
richt@180
   585
           <p>
richt@191
   586
             When a previously known instance of a networked service matching one of the requested <a href="#dfn-valid-service-type">valid service types</a> becomes unavailable on the user's current network, the <a>user agent</a> MUST decrement the <a href="#dom-networkservices-servicesavailable"><code>servicesAvailable</code></a> attribute by <code>1</code> and then
richt@191
   587
             <a href="http://www.whatwg.org/specs/web-apps/current-work/complete/webappapis.html#queue-a-task" class="externalDFN">queue a task</a>
richt@191
   588
              to dispatch a newly created event with the name <code>serviceunavailable</code> that uses the <code>Event</code> interface, which does
richt@191
   589
              not bubble, is not cancellable, and has no default action, at the current <a href="#networkservices"><code>NetworkServices</code></a>
richt@191
   590
              object.
richt@180
   591
           </p>
richt@180
   592
        </div>
richt@180
   593
richt@180
   594
      </section>
richt@180
   595
richt@180
   596
      <section>
richt@180
   597
      <h2>Methods</h2>
richt@180
   598
        <dl class="domintro">
richt@180
   599
        <dt>
richt@180
   600
          <code title="networkservices-getter">
richt@180
   601
            <a href="#networkservices">services</a>
richt@180
   602
          </code>
richt@180
   603
          [
richt@180
   604
          <var title="">index</var>
richt@180
   605
          ]
richt@180
   606
        </dt>
richt@180
   607
        <dd>
richt@180
   608
          <p>
richt@180
   609
            Returns the specified <a href="#networkservice"><code>NetworkService</code></a> object.
richt@180
   610
          </p>
richt@180
   611
        </dd>
richt@180
   612
        <dt>
richt@180
   613
          <code title="networkservices-getter">
richt@180
   614
            <a href="#networkservices">services</a>
richt@180
   615
          </code>
richt@180
   616
          .
richt@180
   617
          <code title="dom-networkservices-getservicebyid">
richt@180
   618
            <a href="#dom-networkservices-getservicebyid">getServiceById</a>
richt@180
   619
          </code>
richt@180
   620
          (
richt@180
   621
          <var title="">id</var>
richt@180
   622
          )
richt@180
   623
        </dt>
richt@180
   624
        <dd>
richt@180
   625
          <p>
richt@180
   626
            Returns the <a href="#networkservice"><code>NetworkService</code></a> object with the given identifier, or null if no
richt@180
   627
            service has that identifier.
richt@180
   628
          </p>
richt@180
   629
        </dd>
richt@180
   630
      </dl>
richt@180
   631
richt@180
   632
      <p>
richt@230
   633
        A <a href="#networkservices"><code>NetworkServices</code></a> object represents the current list of one or more current authorized services - the <a>list of authorized service records</a>. Each item in the <a>list of authorized service records</a> is represented by a <a href="#networkservice"><code>NetworkService</code></a> object. The <a>list of authorized service records</a> is <span>immutable</span> meaning that it cannot be modified for the lifetime of a <a href="#networkservices"><code>NetworkServices</code></a> object.
richt@180
   634
      </p>
richt@180
   635
richt@180
   636
      <p class="note">
richt@230
   637
        Each service in a <a href="#networkservices"><code>NetworkServices</code></a> object thus has an index; the first has the index 0, and each subsequent service is numbered one higher than the previous one.
richt@180
   638
      </p>
richt@180
   639
richt@180
   640
      <p>
richt@230
   641
        The <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/infrastructure.html#supported-property-indices" class="externalDFN">supported property indices</a> of <a href="#networkservices"><code>NetworkServices</code></a> objects at any instant are the numbers from zero to the number of items in the <a>list of authorized service records</a> represented by the respective object minus one, if any services are represented in the <a>list of authorized service records</a>.
richt@180
   642
      </p>
richt@180
   643
richt@180
   644
      <p>
richt@230
   645
        To <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/infrastructure.html#determine-the-value-of-an-indexed-property" class="externalDFN">determine the value of an indexed property</a> for a given index <var>index</var> in a <a href="#networkservices"><code>NetworkServices</code></a> object's <a>list of authorized service records</a>, the user agent MUST return the <a href="#networkservice"><code>NetworkService</code></a> object that represents the <var>index</var>th service in the <a>list of authorized service records</a>.
richt@180
   646
      </p>
richt@180
   647
richt@180
   648
      <p>
richt@230
   649
        The <dfn id="dom-networkservices-getservicebyid"><code>getServiceById(id)</code></dfn> method MUST return the first <a href="#networkservice"><code>NetworkService</code></a> object in the <a>list of authorized service records</a> represented by the respective object whose <a href="#dom-networkservice-id"><code>id</code></a> attribute is equal to the value of the <var>id</var> argument.
richt@230
   650
        When no services in the <a>list of authorized service records</a> match the given argument, the method MUST return null.
richt@180
   651
      </p>
richt@180
   652
richt@180
   653
      <p>
richt@180
   654
         Services available within the local network can connect and disconnect at different times during the execution of a web page. A <a>user agent</a> can
richt@180
   655
         inform a web page when the state of networked services matching the requested <a>valid service type</a> change. Web pages can use this information to enable in-page experiences for communicating the state of networked services
richt@180
   656
         with the ability to change the particular service or set of services the page is connected to by re-invoking the <a href="#dom-navigator-getnetworkservices"><code>getNetworkServices()</code></a> method.
richt@180
   657
      </p>
richt@180
   658
richt@180
   659
      </section>
richt@180
   660
richt@180
   661
      <section>
richt@180
   662
      <h2>Events</h2>
richt@180
   663
richt@180
   664
      <p>
richt@180
   665
         The following are the event handlers (and their corresponding event handler event types) that must be supported, as IDL attributes, by all objects implementing the <a href="#networkservices"><code>NetworkServices</code></a> interface:
richt@180
   666
       </p>
richt@180
   667
richt@180
   668
       <table border="1">
richt@180
   669
        <thead>
richt@180
   670
          <tr>
richt@180
   671
            <th>
richt@180
   672
              <span title="event handlers">Event handler</span>
richt@180
   673
            </th>
richt@180
   674
            <th>
richt@180
   675
              <span>Event handler event type</span>
richt@180
   676
            </th>
richt@180
   677
          </tr>
richt@180
   678
        </thead>
richt@180
   679
        <tbody>
richt@180
   680
          <tr>
richt@180
   681
            <td>
richt@180
   682
              <dfn id="dom-networkservices-onserviceavailable" title="dom-NetworkServices-onserviceavailable">
richt@180
   683
                <code>onserviceavailable</code>
richt@180
   684
              </dfn>
richt@180
   685
            </td>
richt@180
   686
            <td>
richt@180
   687
              <code title="event-serviceavailable">serviceavailable</code>
richt@180
   688
            </td>
richt@180
   689
          </tr>
richt@180
   690
          <tr>
richt@180
   691
            <td>
richt@180
   692
              <dfn id="dom-networkservices-onserviceunavailable" title="dom-NetworkServices-onserviceunavailable">
richt@180
   693
                <code>onserviceunavailable</code>
richt@180
   694
              </dfn>
richt@180
   695
            </td>
richt@180
   696
            <td>
richt@180
   697
              <code title="event-serviceunavailable">serviceunavailable</code>
richt@180
   698
            </td>
richt@180
   699
          </tr>
richt@180
   700
        </tbody>
richt@180
   701
      </table>
richt@180
   702
richt@180
   703
      <p>
richt@180
   704
         Events with an event type of <code>serviceavailable</code> or <code>serviceunavailable</code> defined in this specification are simple <code>Event</code> objects.
richt@180
   705
      </p>
richt@180
   706
richt@180
   707
      </section>
richt@180
   708
richt@180
   709
    </section>
richt@180
   710
    <section>
richt@180
   711
    <h2>Communicating with a networked service</h3>
richt@180
   712
richt@180
   713
<p>
richt@180
   714
   The <a href="#networkservice"><code>NetworkService</code></a> interface is used to provide a set of connection information for an HTTP service endpoint and if available, service events, running on a networked device.
richt@180
   715
</p>
richt@180
   716
richt@180
   717
<pre class="widl">
richt@180
   718
[NoInterfaceObject]
richt@180
   719
interface <dfn id="networkservice">NetworkService</dfn> {
richt@180
   720
  readonly attribute DOMString        <a href="#dom-networkservice-id">id</a>;
richt@180
   721
  readonly attribute DOMString        <a href="#dom-networkservice-name">name</a>;
richt@180
   722
  readonly attribute DOMString        <a href="#dom-networkservice-type">type</a>;
richt@180
   723
  readonly attribute DOMString        <a href="#dom-networkservice-url">url</a>;
richt@180
   724
  readonly attribute DOMString        <a href="#dom-networkservice-config">config</a>;
richt@180
   725
richt@191
   726
  readonly attribute boolean          <a href="#dom-networkservice-online">online</a>;
richt@180
   727
richt@180
   728
  // event handler attributes
richt@191
   729
           attribute <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/webappapis.html#eventhandler" class="externalDFN">EventHandler</a>     <a href="#dom-networkservice-onserviceonline">onserviceonline</a>;
richt@191
   730
           attribute <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/webappapis.html#eventhandler" class="externalDFN">EventHandler</a>     <a href="#dom-networkservice-onserviceoffline">onserviceoffline</a>;
richt@191
   731
richt@191
   732
           attribute <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/webappapis.html#eventhandler" class="externalDFN">EventHandler</a>     <a href="#dom-networkservice-onnotify">onnotify</a>;
richt@180
   733
};
richt@180
   734
richt@180
   735
<a href="#networkservice">NetworkService</a> implements <a href="http://dvcs.w3.org/hg/domcore/raw-file/tip/Overview.html#interface-eventtarget" class="externalDFN">EventTarget</a>;
richt@180
   736
</pre>
richt@180
   737
richt@180
   738
<section>
richt@180
   739
  <h2>Attributes</h2>
richt@180
   740
richt@180
   741
      <dl class="domintro">
richt@180
   742
        <dt>
richt@180
   743
          <var title="">service</var>
richt@180
   744
           .
richt@180
   745
          <code title="dom-networkservice-id">
richt@180
   746
            <a href="#dom-networkservice-id">id</a>
richt@180
   747
          </code>
richt@180
   748
        </dt>
richt@180
   749
        <dd>
richt@180
   750
          <p>
richt@180
   751
            A unique identifier for the given user-selected service instance.
richt@180
   752
          </p>
richt@180
   753
        </dd>
richt@180
   754
        <dt>
richt@180
   755
          <var title="">service</var>
richt@180
   756
           .
richt@180
   757
          <code title="dom-networkservice-name">
richt@180
   758
            <a href="#dom-networkservice-name">name</a>
richt@180
   759
          </code>
richt@180
   760
        </dt>
richt@180
   761
        <dd>
richt@180
   762
          <p>
richt@180
   763
            The name of the user-selected service.
richt@180
   764
          </p>
richt@180
   765
        </dd>
richt@180
   766
        <dt>
richt@180
   767
          <var title="">service</var>
richt@180
   768
           .
richt@180
   769
          <code title="dom-networkservice-type">
richt@180
   770
            <a href="#dom-networkservice-type">type</a>
richt@180
   771
          </code>
richt@180
   772
        </dt>
richt@180
   773
        <dd>
richt@180
   774
          <p>
richt@180
   775
            The <a>valid service type</a> token value of the user-selected service.
richt@180
   776
          </p>
richt@180
   777
        </dd>
richt@180
   778
        <dt>
richt@180
   779
          <var title="">service</var>
richt@180
   780
           .
richt@180
   781
          <code title="dom-networkservice-url">
richt@180
   782
            <a href="#dom-networkservice-url">url</a>
richt@180
   783
          </code>
richt@180
   784
        </dt>
richt@180
   785
        <dd>
richt@180
   786
          <p>
richt@180
   787
            The control URL endpoint (including any required port information) of the user-selected control service that has been added to the <a>entry script origin's URL whitelist</a>.
richt@180
   788
          </p>
richt@180
   789
        </dd>
richt@180
   790
        <dt>
richt@180
   791
          <var title="">service</var>
richt@180
   792
           .
richt@180
   793
          <code title="dom-networkservice-config">
richt@180
   794
            <a href="#dom-networkservice-config">config</a>
richt@180
   795
          </code>
richt@180
   796
        </dt>
richt@180
   797
        <dd>
richt@180
   798
          <p>
richt@180
   799
            The configuration information associated with the service depending on the requested service type.
richt@180
   800
          </p>
richt@180
   801
        </dd>
richt@180
   802
      </dl>
richt@180
   803
richt@180
   804
          <p>
richt@197
   805
            The <dfn id="dom-networkservice-id"><code>id</code></dfn> attribute is a unique identifier for the service. The same service provided at different times or on different objects MUST have the same <a href="#dom-networkservice-id"><code>id</code></a> value.
richt@180
   806
         </p>
richt@180
   807
richt@180
   808
         <p>
richt@180
   809
            The <dfn id="dom-networkservice-name"><code>name</code></dfn> attribute represents a human-readable title for the service.
richt@180
   810
         </p>
richt@180
   811
richt@180
   812
         <p>
richt@180
   813
             The <dfn id="dom-networkservice-type"><code>type</code></dfn> attribute reflects the value of the <a>valid service type</a> of the service.
richt@180
   814
          </p>
richt@180
   815
richt@180
   816
         <p>
richt@180
   817
            The <dfn id="dom-networkservice-url"><code>url</code></dfn> attribute is an <a href="http://www.w3.org/TR/html5/urls.html#absolute-url" class="externalDFN">absolute URL</a> pointing to the root HTTP
richt@180
   818
            endpoint for the service that has been added to the <a>entry script origin's URL whitelist</a>. Web pages can subsequently use this value for implicit cross-document messaging via various existing mechanisms (e.g. Web Sockets, Server-Sent Events, Web Messaging, XMLHttpRequest).
richt@180
   819
         </p>
richt@180
   820
richt@180
   821
         <p>
richt@180
   822
            The <dfn id="dom-networkservice-config"><code>config</code></dfn> attribute provides the raw configuration information extracted from the given network service.
richt@180
   823
         </p>
richt@180
   824
richt@180
   825
      </section>
richt@180
   826
richt@180
   827
      <section>
richt@180
   828
         <h3>States</h3>
richt@180
   829
richt@180
   830
      <dl class="domintro">
richt@180
   831
        <dt>
richt@180
   832
          <var title="">service</var>
richt@180
   833
           .
richt@191
   834
          <code title="dom-networkservice-online">
richt@191
   835
            <a href="#dom-networkservice-online">online</a>
richt@180
   836
          </code>
richt@180
   837
        </dt>
richt@180
   838
        <dd>
richt@180
   839
          <p>
richt@191
   840
            Returns <code>true</code> if the service is reporting that it is accessible on the local network or <code>false</code> if the service is reporting that it is no longer accessible (temporarily or permanently) on the local network.
richt@180
   841
          </p>
richt@180
   842
        </dd>
richt@180
   843
      </dl>
richt@180
   844
richt@191
   845
      <p>
richt@195
   846
        The <dfn id="dom-networkservice-online"><code>online</code></dfn> attribute indicates whether the service is reporting itself as being
richt@191
   847
        either <var>online</var>, and therefore accessible on the local network, in which case this attribute will return <code>true</code> or, <var>offline</var>, and therefore not accessible on the local network, either temporarily or permanently, in which case this attribute will return <code>false</code>. This attribute MUST default to <code>true</code>.
richt@191
   848
      </p>
richt@180
   849
richt@180
   850
      </section>
richt@180
   851
richt@180
   852
      <section>
richt@180
   853
         <h3>Events</h3>
richt@180
   854
richt@180
   855
      <p>
richt@180
   856
         The following are the event handlers (and their corresponding event handler event types) that must be supported, as IDL attributes, by all objects implementing the
richt@180
   857
         <a href="#networkservice"><code>NetworkService</code></a> interface:
richt@180
   858
       </p>
richt@180
   859
richt@180
   860
       <table border="1">
richt@180
   861
        <thead>
richt@180
   862
          <tr>
richt@180
   863
            <th>
richt@180
   864
              <span title="event handlers">Event handler</span>
richt@180
   865
            </th>
richt@180
   866
            <th>
richt@180
   867
              <span>Event handler event type</span>
richt@180
   868
            </th>
richt@180
   869
          </tr>
richt@180
   870
        </thead>
richt@180
   871
        <tbody>
richt@180
   872
          <tr>
richt@180
   873
            <td>
richt@191
   874
              <dfn id="dom-networkservice-onnotify" title="dom-NetworkService-onnotify">
richt@191
   875
                <code>onnotify</code>
richt@180
   876
              </dfn>
richt@180
   877
            </td>
richt@180
   878
            <td>
richt@191
   879
              <code title="event-notify">notify</code>
richt@180
   880
            </td>
richt@180
   881
          </tr>
richt@180
   882
          <tr>
richt@180
   883
            <td>
richt@191
   884
              <dfn id="dom-networkservice-onserviceonline" title="dom-NetworkService-onserviceonline">
richt@191
   885
                <code>onserviceonline</code>
richt@180
   886
              </dfn>
richt@180
   887
            </td>
richt@180
   888
            <td>
richt@191
   889
              <code title="event-onserviceonline">serviceonline</code>
richt@191
   890
            </td>
richt@191
   891
          </tr>
richt@191
   892
          <tr>
richt@191
   893
            <td>
richt@195
   894
              <dfn id="dom-networkservice-onserviceoffline" title="dom-NetworkService-onserviceoffline">
richt@191
   895
                <code>onserviceoffline</code>
richt@191
   896
              </dfn>
richt@191
   897
            </td>
richt@191
   898
            <td>
richt@191
   899
              <code title="event-onserviceoffline">serviceoffline</code>
richt@180
   900
            </td>
richt@180
   901
          </tr>
richt@180
   902
        </tbody>
richt@180
   903
      </table>
richt@180
   904
richt@180
   905
      <p>
richt@191
   906
         Events with an event type of <code>notify</code>, <code>serviceonline</code> or <code>serviceoffline</code> defined in this specification are simple <code>Event</code> objects.
richt@180
   907
      </p>
richt@180
   908
richt@180
   909
      </section>
richt@180
   910
   </section>
richt@180
   911
richt@180
   912
      <section>
richt@180
   913
            <h2>Service Discovery</h2>
richt@180
   914
richt@180
   915
      <p>
richt@192
   916
         A <a>user agent</a> conforming to this specification MAY implement <acronym title="Simple Service Discovery Protocol">SSDP</acronym> [[!UPNP-DEVICEARCH11]] and Zeroconf [[!DNS-SD]] + [[!MDNS]] service discovery mechanisms
richt@180
   917
         to enable Web pages to request and connect with HTTP services running on networked devices, discovered via either mechanism, through this API. When a <a>user agent</a> implements either of these service discovery mechanisms, then it MUST conform to the corresponding algorithms provided in this section of the specification.
richt@180
   918
      </p>
richt@180
   919
      <p>
richt@180
   920
         This section presents how the results of these two service discovery
richt@230
   921
         mechanisms will be matched to requested service types, how the user agent stores available and active services, how their properties are applied to any resulting <a href="#networkservice"><code>NetworkService</code></a> objects.
richt@180
   922
      </p>
richt@180
   923
richt@180
   924
      <p>
richt@180
   925
         It is expected that user agents will perform these service discovery mechansisms asynchronously and periodically update the <a>list of networked devices</a> as required. The timing of any
richt@180
   926
         service discovery mechanisms is an implementation detail left to the discretion of the implementer (e.g. once on user agent start-up, every X seconds during user agent execution or on
richt@180
   927
         invocation of this API from a Web page).
richt@180
   928
      </p>
richt@180
   929
richt@180
   930
      <p>
richt@230
   931
         The <dfn>list of available service records</dfn> is a single dynamic internal lookup table within user agents that is used to track all the  services that have been discovered and are available in the current network at any given time.
richt@180
   932
         At any point during the running of either of the two service discovery mechanisms then existing entries within this table can be updated, entries can be added and entries can be removed as the status of networked
richt@230
   933
         services changes according to the rules defined in this specification. <!--Each record contained within this table contains the attributes: <code>id</code>, <code>deviceId</code>, <code>name</code>, <code>type</code>, <code>url</code>, <code>config</code> and <code>expiryTimestamp</code>.-->
richt@180
   934
      </p>
richt@180
   935
richt@230
   936
      <p>
richt@230
   937
        The <dfn>list of authorized service records</dfn> is a single dynamic internal lookup table within user agents that is used to track the
richt@230
   938
        current services that are being shared with web pages at any given time from the <a>list of available service records</a>. Each record in the <a>list of authorized service records</a> is associated with a <var>services manager</var> object that is assigned as part of the
richt@230
   939
         <a href="#dom-navigator-getnetworkservices"><code>getNetworkServices()</code></a> algorithm.
richt@230
   940
      </p>
richt@230
   941
richt@230
   942
      <p>
richt@230
   943
        The rule for <dfn>adding an available service</dfn> is the process of adding a new service or updating an existing service in the <a>list of available service records</a> that is generally available on the user's current network. This rule takes one argument, <var>network service record</var>, and consists of
richt@230
   944
        running the following steps:
richt@230
   945
      </p>
richt@230
   946
richt@230
   947
      <ol class="rule">
richt@230
   948
richt@230
   949
        <li>
richt@230
   950
          Let <var>new service registration flag</var> be <code>true</code>.
richt@230
   951
        </li>
richt@230
   952
richt@230
   953
        <li>
richt@230
   954
           For each <var>existing service record</var> in the current <a>list of available service records</a>, run the following sub-steps:
richt@230
   955
           <ol class="rule">
richt@230
   956
richt@230
   957
             <li>
richt@230
   958
              If the <var>existing service record</var>'s <code>id</code> property does not equal <var>network service record</var>'s <code>id</code>
richt@230
   959
               property then abort any remaining sub-steps and continue at the next available <var>existing service record</var>.
richt@230
   960
             </li>
richt@230
   961
richt@230
   962
             <li>
richt@230
   963
              Set <var>new service registration flag</var> to <code>false</code>.
richt@230
   964
             </li>
richt@230
   965
richt@230
   966
             <li>
richt@230
   967
               Replace the value of <var>existing service record</var> in the current <a>list of available service records</a> with the value of
richt@230
   968
              <var>network service record</var>.
richt@230
   969
             </li>
richt@230
   970
           </ol>
richt@230
   971
        </li>
richt@230
   972
richt@230
   973
        <li>
richt@230
   974
           If <var>new service registration flag</var> is set to <code>true</code> then add <var>network service record</var> to the <a>list of available service records</a> as a new entry.
richt@230
   975
        </li>
richt@230
   976
richt@230
   977
        <li>
richt@230
   978
          For each <var>active service</var> in the <a>list of authorized service records</a> run the following steps:
richt@230
   979
richt@230
   980
          <ol class="rule">
richt@230
   981
richt@230
   982
            <li>
richt@230
   983
               If <var>network service record</var>'s <code>type</code> property does not equal the current <var>active service</var>'s
richt@230
   984
                <code>type</code> attribute then abort any remaining sub-steps for this <var>active service</var> and continue at the next available <var>active service</var>.
richt@230
   985
            </li>
richt@230
   986
richt@230
   987
            <li>
richt@230
   988
               If the <var>new service registration flag</var> is set to <code>true</code> then increment the <a href="#dom-networkservices-servicesavailable"><code>servicesAvailable</code></a> attribute of the <var>services manager</var> associated with
richt@230
   989
               the current <var>active service</var>
richt@230
   990
                object by <code>1</code> and then <a href="http://www.whatwg.org/specs/web-apps/current-work/complete/webappapis.html#queue-a-task" class="externalDFN">queue a task</a>
richt@230
   991
                 to dispatch a newly created event with the name <a href="#dom-networkservices-onserviceavailable"><code>serviceavailable</code></a> that uses the <code>Event</code> interface,
richt@230
   992
                 which does not bubble, is not cancellable, and has no default action, at the <var>services manager</var> associated with
richt@230
   993
                 the current <var>active service</var> object.
richt@230
   994
            </li>
richt@230
   995
richt@230
   996
            <li>
richt@230
   997
               <a href="http://www.whatwg.org/specs/web-apps/current-work/complete/webappapis.html#queue-a-task" class="externalDFN">Queue a task</a>
richt@230
   998
                to dispatch a newly created event with the name <a href="#dom-networkservice-onserviceonline"><code>serviceonline</code></a> that uses the <code>Event</code> interface, which
richt@230
   999
                 does not bubble, is not cancellable, and has no default action, at the current
richt@230
  1000
                <var>active service</var> object.
richt@230
  1001
            </li>
richt@230
  1002
richt@230
  1003
          </ol>
richt@230
  1004
richt@230
  1005
        </li>
richt@230
  1006
richt@230
  1007
      </ol>
richt@230
  1008
richt@230
  1009
richt@230
  1010
      <p>
richt@230
  1011
        The rule for <dfn>removing an available service</dfn> is the general process of removing a service from the
richt@230
  1012
        <a>list of available service records</a>
richt@230
  1013
         that has left the user's current network or has otherwise expired. This rule takes one argument, <var>service identifier</var>, and consists of running the following steps:</p>
richt@230
  1014
richt@230
  1015
      <ol class="rule">
richt@230
  1016
richt@230
  1017
        <li>
richt@230
  1018
           For each <var>existing service record</var> in the current <a>list of available service records</a>, run the following sub-steps:
richt@230
  1019
           <ol class="rule">
richt@230
  1020
richt@230
  1021
             <li>
richt@230
  1022
              If the <var>existing service record</var>'s <code>id</code> property does not match <var>service identifier</var> then skip any remaining sub-steps for the current <var>existing service record</var> and continue at the next available <var>existing service record</var>.
richt@230
  1023
             </li>
richt@230
  1024
richt@230
  1025
             <li>
richt@230
  1026
               If the <var>existing service record</var>'s <code>type</code> property begins with the DOMString "<code>upnp:</code>" and
richt@230
  1027
               <var>existing service record</var>'s <code>eventsURL</code> property is set then run the rule to
richt@230
  1028
               <a>terminate an existing UPnP Events Subscription</a>, if one is currently active (as a result of having previously called
richt@230
  1029
               <a>setup a UPnP Events Subscription</a> against the current <var>existing service record</var>).
richt@230
  1030
             </li>
richt@230
  1031
richt@230
  1032
             <li>
richt@230
  1033
               For each <var>active service</var> in <a>list of authorized service records</a> run the following steps:
richt@230
  1034
richt@230
  1035
               <ol class="rule">
richt@230
  1036
richt@230
  1037
                 <li>
richt@230
  1038
                    If <var>existing service record</var>'s <code>type</code> property does not equal the current <var>active service</var>'s
richt@230
  1039
                     <code>type</code> attribute then abort any remaining sub-steps for this <var>active service</var> and continue at the next available <var>active service</var>.
richt@230
  1040
                 </li>
richt@230
  1041
richt@230
  1042
                 <li>
richt@230
  1043
                    Decrement the <a href="#dom-networkservices-servicesavailable"><code>servicesAvailable</code></a> attribute of the
richt@230
  1044
                    <var>services manager</var> associated with the current <var>active service</var>
richt@230
  1045
                     object by <code>1</code> and then <a href="http://www.whatwg.org/specs/web-apps/current-work/complete/webappapis.html#queue-a-task" class="externalDFN">queue a task</a>
richt@230
  1046
                      to dispatch a newly created event with the name <a href="#dom-networkservices-onserviceunavailable"><code>serviceunavailable</code></a> that uses the <code>Event</code> interface,
richt@230
  1047
                      which does not bubble, is not cancellable, and has no default action, at the <var>services manager</var> associated with
richt@230
  1048
                      the current <var>active service</var> object.
richt@230
  1049
                 </li>
richt@230
  1050
richt@230
  1051
                 <li>
richt@230
  1052
                    <a href="http://www.whatwg.org/specs/web-apps/current-work/complete/webappapis.html#queue-a-task" class="externalDFN">Queue a task</a>
richt@230
  1053
                     to dispatch a newly created event with the name <a href="#dom-networkservice-onserviceoffline"><code>serviceoffline</code></a> that uses the <code>Event</code> interface, which
richt@230
  1054
                      does not bubble, is not cancellable, and has no default action, at the current
richt@230
  1055
                     <var>active service</var> object.
richt@230
  1056
                 </li>
richt@230
  1057
richt@230
  1058
               </ol>
richt@230
  1059
richt@230
  1060
             </li>
richt@230
  1061
richt@230
  1062
             <li>
richt@230
  1063
               Remove <var>existing service record</var> from the current <a>list of available service records</a>.
richt@230
  1064
             </li>
richt@230
  1065
richt@230
  1066
           </ol>
richt@230
  1067
        </li>
richt@230
  1068
richt@230
  1069
      </ol>
richt@230
  1070
richt@230
  1071
      <p>
richt@230
  1072
       User agents <em class="ct">SHOULD</em> expire a service record from the <a>list of available service records</a> when its
richt@230
  1073
       <code>expiryTimestamp</code> attribute exceeds the current UTC timestamp. When this condition is met the <a>user agent</a> SHOULD
richt@230
  1074
       run the rule for <a>removing an available service</a>, passing in the expired service record's <code>id</code> attribute as the
richt@230
  1075
       only argument.
richt@230
  1076
      </p>
richt@230
  1077
richt@230
  1078
richt@230
  1079
      <section>
robin@185
  1080
         <h4>Zeroconf (<abbr title="Multicast DNS">mDNS</abbr> + <abbr title="Domain Name System">DNS</abbr>-<abbr title="Service Discovery">SD</abbr>)</h4>
richt@180
  1081
richt@180
  1082
         <p>
robin@185
  1083
            For each DNS response received from a user-agent-initiated Multicast DNS Browse for <abbr title="DNS Pointer Record">PTR</abbr> records with the name <code>_services._dns-sd._udp</code> on the resolved recommended automatic browsing
richt@180
  1084
   domain [[!MDNS]], the <a>user agent</a> MUST run the following steps:
richt@180
  1085
         </p>
richt@180
  1086
richt@180
  1087
         <ol class="rule">
richt@180
  1088
richt@180
  1089
            <li>Let <var>service mDNS responses</var> be an array of PTR records received by issuing a Multicast DNS Browse for PTR records with the name of the current discovered service type.</li>
richt@180
  1090
richt@180
  1091
            <li>For each Object <var>service mDNS response</var> in <var>service mDNS responses</var>, run the following steps:
richt@180
  1092
               <ol>
richt@180
  1093
richt@180
  1094
                  <li>
richt@230
  1095
                     Let <var>network service record</var> be an Object consisting of the following empty properties: <code>id</code>, <code>name</code>, <code>type</code>, <code>url</code>, <code>config</code>, <code>expiryTimestamp</code>.
richt@180
  1096
                  </li>
richt@180
  1097
richt@180
  1098
                  <li>
richt@180
  1099
                     Set <var>network service record</var>'s <code>id</code> property to the value of the full PTR Service Instance Name [[!MDNS]].
richt@180
  1100
                  </li>
richt@180
  1101
richt@180
  1102
                  <li>
richt@180
  1103
                     Set <var>network service record</var>'s <code>name</code> property to the value of the PTR Service Instance Name's <var>Instance</var> component [[!MDNS]].
richt@180
  1104
                  </li>
richt@180
  1105
richt@180
  1106
                  <li>
richt@180
  1107
                     Set <var>network service record</var>'s <code>type</code> property to the concatenation of the string <code>zeroconf:</code> followed by the value of the PTR Service Instance Name's <var>Service</var> component [[!MDNS]].
richt@180
  1108
                  </li>
richt@180
  1109
richt@180
  1110
                  <li>
richt@180
  1111
                     Set <var>network service record</var>'s <code>url</code> property to the resolvable Service URL obtained from performing an DNS-SD Lookup [[!DNS-SD]] of the current service from the PTR record provided [[!MDNS]].
richt@180
  1112
                  </li>
richt@180
  1113
richt@180
  1114
                  <li>
richt@180
  1115
                     Set <var>network service record</var>'s <code>config</code> property to the string value of the contents of the first DNS-SD TXT record associated with the <var>service mDNS response</var> as defined in [[!DNS-SD]].
richt@180
  1116
                  </li>
richt@180
  1117
richt@180
  1118
                  <li>
richt@230
  1119
                     Set <var>network service record</var>'s <code>expiryTimestamp</code> property to the value of the current date, in UTC timestamp format, plus a value of <code>120</code> seconds.
richt@180
  1120
                  </li>
richt@180
  1121
richt@180
  1122
                  <li>
richt@230
  1123
                     Run the general rule for <a>adding an available service</a>, passing in the current <var>network service record</var> as the
richt@230
  1124
                     only argument.
richt@180
  1125
                  </li>
richt@180
  1126
richt@180
  1127
            </ol>
richt@180
  1128
           </li>
richt@180
  1129
         </ol>
richt@180
  1130
richt@180
  1131
      </section>
richt@180
  1132
richt@180
  1133
      <section>
robin@185
  1134
         <h5>Universal Plug-and-Play (<abbr title="Universal Plug-and-Play">UPnP</abbr>)</h5>
richt@180
  1135
richt@180
  1136
         <p>
richt@230
  1137
          A user agent that implements UPnP service discovery must issue an <dfn>advertisement for UPnP root devices</dfn> against the user's
richt@230
  1138
          current local network according to the full normative text and timing provided in 'Section 1.3.2: Search request with M-SEARCH' detailed in [[!UPNP-DEVICEARCH11]].
richt@230
  1139
          </p>
richt@230
  1140
richt@230
  1141
          <p>
richt@230
  1142
            The user agent <em class="ct">MUST</em> issue all <a title="advertisement for UPnP root devices">advertisements for UPnP root devices</a> with a HTTP request line equal to <code>M-SEARCH * HTTP/1.1</code>, with a HOST header equal to the reserved multicast address and port of <code>239.255.255.250:1900</code>, a MAN header equal to <code>ssdp:discover</code>, an ST header equal to <code>upnp:rootdevice</code> and a user-agent defined MX header equal to a <dfn>maximum UPnP advertisement response wait time</dfn> value between <code>1</code> and <code>5</code> seconds.
richt@230
  1143
         </p>
richt@230
  1144
richt@230
  1145
         <p>
richt@230
  1146
          The user agent <em class="ct">MUST</em> listen for incoming requests and process any incoming responses to any <a>advertisement for UPnP root devices</a> on the <dfn>standard UPnP address and port</dfn>, on all current local network interface addresses with the port <code>1900</code>, according to the rules defined in this section.
richt@230
  1147
         </p>
richt@230
  1148
richt@230
  1149
         <p>
richt@230
  1150
          For each <dfn>HTTP Response</dfn> following an initial <a>advertisement for UPnP root devices</a> sent on a <a>standard UPnP address
richt@230
  1151
            and port</a> the user agent <em class="ct">MUST</em> run the following steps:
richt@180
  1152
         </p>
richt@180
  1153
richt@180
  1154
         <ol class="rule">
richt@230
  1155
          <li>
richt@230
  1156
            If the <a>HTTP Response</a> is not a HTTP 200 OK response then this response is invalid and the user agent <em class="ct">MUST</em> discard this response, abort any remaining steps and return. The user agent <em class="ct">MAY</em> issue a new <a>advertisement for UPnP root devices</a> as a result of this error occurring.
richt@230
  1157
          </li>
richt@180
  1158
richt@230
  1159
          <li>
richt@230
  1160
            If the <a>maximum UPnP advertisement response wait time</a> has been exceeded since the initial <a>advertisement for UPnP root devices</a> was sent then the <a>HTTP Response</a> is invalid and the user agent <em class="ct">MUST</em> discard this response, abort any remaining steps and return.
richt@230
  1161
          </li>
richt@180
  1162
richt@230
  1163
          <li>
richt@230
  1164
             Let <var>ssdp device</var> be an Object with a property for each HTTP header received in the <a>HTTP Response</a>, with each key being the name of a HTTP response header and each value being that HTTP response header's value.
richt@230
  1165
          </li>
richt@180
  1166
richt@230
  1167
          <li>
richt@230
  1168
            If <var>ssdp device</var> does not contain at least one <var>CACHE-CONTROL</var> entry, at least one <var>USN</var> entry, at least one <var>ST</var> entry and at least one <var>LOCATION</var> entry or the value of its <var>ST</var> entry is not <code>upnp:rootdevice</code>, then the <a>HTTP Response</a> is invalid and the <a>user agent</a> MUST discard this response, abort any remaining steps and return.
richt@230
  1169
          </li>
richt@180
  1170
richt@230
  1171
          <li>
richt@230
  1172
            The user agent <em class="ct">MUST</em> run the rule for <a>processing a UPnP Device Description File</a> passing in the first occurrence of <var>LOCATION</var> from <var>ssdp device</var> as the <var>device descriptor</var> argument and the first occurrence of <var>USN</var> from <var>ssdp device</var> as the <var>device identifier</var> argument and the first occurrence of <var>CACHE-CONTROL</var> from <var>ssdp device</var> as the <var>device expiry</var> argument
richt@230
  1173
          </li>
richt@180
  1174
richt@230
  1175
        </ol>
richt@180
  1176
richt@230
  1177
        <p>
richt@230
  1178
          For each <dfn>HTTP Request</dfn> received on a <a>standard UPnP address and port</a> the user agent <em class="ct">MUST</em> run the following steps:
richt@230
  1179
         </p>
richt@180
  1180
richt@230
  1181
        <ol class="rule">
richt@180
  1182
richt@230
  1183
          <li>
richt@230
  1184
            If the <a>HTTP Request</a> is not a HTTP NOTIFY request then it is not a valid UPnP Request and the user agent <em class="ct">MUST</em> return a HTTP 200 OK response, discard this request, abort any remaining steps and return.
richt@230
  1185
          </li>
richt@180
  1186
richt@230
  1187
          <li>
richt@230
  1188
             Let <var>ssdp device</var> be an Object with a property for each HTTP header received in the <a>HTTP Request</a>, with each key being the name of a HTTP header and each value being that HTTP header's value.
richt@230
  1189
          </li>
richt@180
  1190
richt@230
  1191
          <li>
richt@230
  1192
            If <var>ssdp device</var> does not contain at least one <var>CACHE-CONTROL</var> entry, at least one <var>USN</var> entry, at least one <var>NT</var> entry, at least one <var>NTS</var> entry and at least one <var>LOCATION</var> entry or the value of its <var>NT</var> entry is not <code>upnp:rootdevice</code>, then the <a>HTTP Request</a> is a malformed UPnP Request and the <a>user agent</a> MUST return a 400 Bad Request response, discard this request, abort any remaining steps and return.
richt@230
  1193
          </li>
richt@180
  1194
richt@230
  1195
          <li>
richt@230
  1196
            If <var>ssdp device</var>'s <var>NTS</var> entry is equal to <code>ssdp:alive</code> or <code>ssdp:update</code> then the user agent <em class="ct">MUST</em> run the rule for <a>processing a UPnP Device Description File</a> passing in the first occurrence of <var>LOCATION</var> from <var>ssdp device</var> as the <var>device descriptor</var> argument and the first occurrence of <var>USN</var> from <var>ssdp device</var> as the <var>device identifier</var> argument and the first occurrence of <var>CACHE-CONTROL</var> from <var>ssdp device</var> as the <var>device expiry</var>. <br/><br/>Otherwise, if <var>ssdp device</var>'s <var>NTS</var> entry is equal to <code>ssdp:byebye</code> then the user agent <em class="ct">MUST</em> run the rule for <a>removing all services from a registered UPnP Device</a> passing in the first occurrence of <var>USN</var> from <var>ssdp device</var> as the <var>device identifier</var> argument.
richt@230
  1197
          </li>
richt@180
  1198
richt@230
  1199
        </ol>
richt@180
  1200
richt@230
  1201
      <p>
richt@230
  1202
        The rule for <dfn>processing a UPnP Device Description File</dfn> is the process of parsing the contents of a standard UPnP Device Description [[!UPNP-DEVICEARCH11]] and
richt@230
  1203
        registering the UPnP services contained therein within the <a>list of available service records</a>.
richt@230
  1204
      </p>
richt@180
  1205
richt@230
  1206
      <p>The rule for <a>processing a UPnP Device Description File</a> takes three arguments - <var>device descriptor</var>, <var>device identifier</var> and <var>device expiry</var> - and when called the user
richt@230
  1207
         agent <em class="ct">MUST</em> run the following steps:</p>
richt@180
  1208
richt@230
  1209
      <ol class="rule">
richt@180
  1210
richt@230
  1211
          <li>
richt@230
  1212
             Let <var>root device descriptor file</var> contain the contents of the file located at the URL provided in <var>device descriptor</var> obtained according to the rules
richt@230
  1213
             defined in 'Section 2.11: Retrieving a description using HTTP' in [[!UPNP-DEVICEARCH11]]. If the value provided in <var>device descriptor</var> cannot be resolved as a URL on the current network or the <var>root device descriptor file</var> remains empty then the <a>HTTP Response</a> is invalid and the <a>user agent</a> MUST discard this response, abort any remaining steps and return.
richt@230
  1214
          </li>
richt@180
  1215
richt@230
  1216
          <li>
richt@230
  1217
             Let <var>advertised services</var> be a <a>list of all advertised services</a> obtained from the <var>root device descriptor file</var> containing the value of the first occurrence of the <code>&lt;serviceList&gt;</code> element as it is defined in 'Section 2.3: Device Description' in [[!UPNP-DEVICEARCH11]].
richt@230
  1218
          </li>
richt@180
  1219
richt@230
  1220
          <li>
richt@230
  1221
             For each <code>&lt;service&gt;</code> element - known as an <var>advertised service</var> - in <var>advertised services</var> run the following steps:
richt@180
  1222
richt@230
  1223
             <ol class="rule">
richt@230
  1224
richt@230
  1225
                <li>
richt@230
  1226
                   Let <var>network service record</var> be a new Object consisting of the following empty properties: <code>id</code>, <code>deviceId</code>, <code>name</code>, <code>type</code>, <code>url</code>, <code>eventsUrl</code>, <code>config</code>, <code>expiryTimestamp</code>.
richt@230
  1227
                </li>
richt@230
  1228
richt@230
  1229
                <li>
richt@230
  1230
                   Set <var>network service record</var>'s <code>id</code> property to the concatenated string value of <var>device identifier</var> with the <var>advertised service</var>'s <code>&lt;serviceId&gt;</code> sub-element.
richt@230
  1231
                </li>
richt@230
  1232
richt@230
  1233
                <li>
richt@230
  1234
                   Set <var>network service record</var>'s <code>deviceId</code> property to the value of <var>device identifier</var>.
richt@230
  1235
                </li>
richt@230
  1236
richt@230
  1237
                <li>
richt@230
  1238
                   Set <var>network service record</var>'s <code>name</code> property to the string value of the first occurrence of the <var>advertised service</var>'s <code>&lt;serviceId&gt;</code> sub-element.
richt@230
  1239
                </li>
richt@230
  1240
richt@230
  1241
                <li>
richt@230
  1242
                   Set <var>network service record</var>'s <code>type</code> property to the concatenation of the string <code>upnp:</code> followed by the string value of the first occurrence of the <var>advertised service</var>'s <code>&lt;serviceType&gt;</code> sub-element.
richt@230
  1243
                </li>
richt@230
  1244
richt@230
  1245
                <li>
richt@230
  1246
                   Set <var>network service record</var>'s <code>url</code> property to the string value of the first occurrence of the <var>advertised service</var>'s <code>&lt;controlURL&gt;</code> sub-element.
richt@230
  1247
                </li>
richt@230
  1248
richt@230
  1249
                <li>
richt@230
  1250
                   Set <var>network service record</var>'s <code>config</code> property to the string value of the contents of the first occurrence of the <code>&lt;device&gt;</code> element in the <var>root device descriptor file</var>.
richt@230
  1251
                </li>
richt@230
  1252
richt@230
  1253
                <li>
richt@230
  1254
                   If <var>advertised service</var>'s <code>&lt;eventSubURL&gt;</code> sub-element is not empty, then set <var>network service record</var>'s <code>eventsUrl</code> property to the string value of the first occurrence of the <var>advertised service</var>'s <code>&lt;eventSubURL&gt;</code> sub-element. Otherwise, do not set <var>network service record</var>'s <code>eventsUrl</code> property.
richt@230
  1255
                </li>
richt@230
  1256
richt@230
  1257
                <li>
richt@230
  1258
                   Set <var>network service record</var>'s <code>expiryTimestamp</code> property to the value of the current date, in UTC timestamp format, plus the value of <var>device expiry</var>.
richt@230
  1259
                </li>
richt@230
  1260
richt@230
  1261
                <li>
richt@230
  1262
                  Run the general rule for <a>adding an available service</a>, passing in the current <var>network service record</var> as the only argument.
richt@230
  1263
                </li>
richt@230
  1264
richt@230
  1265
              </ol>
richt@230
  1266
richt@230
  1267
          </ol>
richt@230
  1268
richt@230
  1269
         <p>
richt@230
  1270
           The rule for <dfn>removing all services from a registered UPnP Device</dfn> is the process of removing all services associated with a
richt@230
  1271
           device from the <a>list of available service records</a> that has left the user's current network or has otherwise timed out or expired.
richt@230
  1272
           This rule takes one argument, <var>device identifier</var>, and consists of running the following steps:
richt@230
  1273
        </p>
richt@230
  1274
richt@230
  1275
         <ol class="rule">
richt@230
  1276
richt@230
  1277
           <li>
richt@230
  1278
              For each <var>existing service record</var> in the current <a>list of available service records</a>, run the following sub-steps:
richt@230
  1279
              <ol class="rule">
richt@230
  1280
richt@230
  1281
                <li>
richt@230
  1282
                 If the <var>existing service record</var>'s <code>deviceId</code> property does not match <var>device identifier</var> then skip any remaining sub-steps for the current <var>existing service record</var> and continue at the next available <var>existing service record</var>.
richt@230
  1283
                </li>
richt@230
  1284
richt@230
  1285
                <li>
richt@230
  1286
                  Run the general rule for <a>removing an available service</a> passing in <var>existing service record</var>'s <code>id</code>
richt@230
  1287
                  property as the only argument.
richt@230
  1288
                </li>
richt@230
  1289
richt@230
  1290
              </ol>
richt@230
  1291
           </li>
richt@230
  1292
richt@180
  1293
         </ol>
richt@180
  1294
richt@230
  1295
         <p>When the <a>user agent</a> is to <dfn>setup a UPnP Events Subscription</dfn>, it is to run the following steps with the current <var>network service record</var> object as defined in 'Section 4.1.2: SUBSCRIBE with NT and CALLBACK' in [[!UPNP-DEVICEARCH11]]:</p>
richt@180
  1296
richt@180
  1297
         <ol class="rule">
richt@180
  1298
            <li>
richt@180
  1299
               If <var>network service record</var>'s <code>eventsUrl</code> property is empty then the <a>user agent</a> MUST abort these steps.
richt@180
  1300
            </li>
richt@180
  1301
richt@180
  1302
            <li>
richt@180
  1303
               Let <var>callback URL</var> be the value of creating a new <a>user-agent generated callback url</a>.
richt@180
  1304
            </li>
richt@180
  1305
richt@180
  1306
            <li>
richt@230
  1307
               Send a HTTP SUBSCRIBE request with a <em>NT</em> header with a string value of <code>upnp:event</code>, a <em>TIMEOUT</em> header with a user-agent defined timeout value (in the form <code>Second-XX</code> where <code>XX</code> is the user-agent defined timeout value in seconds) and a <em>CALLBACK</em> header
richt@180
  1308
               with a string value of <var>callback URL</var> towards the <var>network service record</var>'s <code>eventsUrl</code> property.
richt@180
  1309
            </li>
richt@180
  1310
richt@180
  1311
            <li>
richt@180
  1312
               If a non-200 OK response is received from the HTTP SUBSCRIBE request then the <a>user agent</a> MUST abort these steps.
richt@180
  1313
            </li>
richt@180
  1314
richt@180
  1315
            <li>
richt@180
  1316
               On receiving a valid 200 OK response, run the following steps:
richt@180
  1317
richt@180
  1318
               <ol class="rule">
richt@180
  1319
                  <li>
richt@180
  1320
                     Let <var>callback ID</var> equal the string value of the first included <em>SID</em> header, if it exists.
richt@180
  1321
                  </li>
richt@180
  1322
                  <li>
richt@230
  1323
                     Let <var>timeout date</var> equal the sum of the current UTC date value plus the integer value of the first included <em>TIMEOUT</em> header (minus the leading string of <code>Second-</code>), if it exists.
richt@180
  1324
                  </li>
richt@180
  1325
                  <li>
richt@180
  1326
                     Run the following steps aynchronously and continue to the step labeled <em>listen</em> below.
richt@180
  1327
                  </li>
richt@180
  1328
                  <li>
richt@180
  1329
                     <em>Refresh Subscription</em>: Run the following steps at a set interval (X) within the <a>user agent</a>:
richt@180
  1330
richt@180
  1331
                     <ol class="rule">
richt@180
  1332
                        <li>
richt@180
  1333
                           Let <var>current date</var> equal the current UTC date.
richt@180
  1334
                        </li>
richt@180
  1335
                        <li>
richt@180
  1336
                           If <var>current date</var> is less than the <var>timeout date</var> then continue to the step labeled <em>refresh subscription</em> above.
richt@180
  1337
                        </li>
richt@180
  1338
                        <li>
richt@230
  1339
                           Send a HTTP SUBSCRIBE request with a <em>SID</em> header with the string value of <var>callback ID</var> and a user-agent defined <em>TIMEOUT</em> header (in the form <code>Second-XX</code> where <code>XX</code> is the user-agent defined timeout value in seconds) towards the <var>network service record</var>'s <code>eventsUrl</code> property.
richt@180
  1340
                        </li>
richt@180
  1341
                        <li>
richt@180
  1342
                           On receiving a valid 200 OK, update <var>callback ID</var> with the string value of the first included <em>SID</em> header, if it exists. All other HTTP
richt@180
  1343
                           responses should cause the <a>user agent</a> to continue from the step labeled <em>refresh subscription</em> above.
richt@180
  1344
                        </li>
richt@180
  1345
                     </ol>
richt@180
  1346
richt@180
  1347
                  </li>
richt@180
  1348
richt@180
  1349
                  <li>
richt@180
  1350
                     <em>Listen</em>: For each HTTP NOTIFY request received at the <var>callback URL</var> the <a>user agent</a> is to run the following steps:
richt@180
  1351
richt@180
  1352
                     <ol class="rule">
richt@180
  1353
                        <li>
richt@180
  1354
                           Let <var>content clone</var> be the result of obtaining the message body of the HTTP NOTIFY request. If <var>content clone</var> is empty, then the <a>user agent</a> MUST abort these steps.
richt@180
  1355
                        </li>
richt@180
  1356
                        <li>
richt@191
  1357
                          Let <var>notification event</var> be a new simple event that uses the <code>Event</code> interface with the name <code>notify</code>,
richt@191
  1358
                           which does not bubble, is not cancellable, and has no default action.
richt@180
  1359
                        </li>
richt@180
  1360
                        <li>
richt@191
  1361
                           Let the <code>data</code> attribute of <var>notification event</var> have the DOMString value of <var>content clone</var>.
richt@180
  1362
                        </li>
richt@180
  1363
                        <li>
richt@180
  1364
                           <a href="http://www.whatwg.org/specs/web-apps/current-work/complete/webappapis.html#queue-a-task" class="externalDFN">Queue a task</a> to
richt@191
  1365
                            dispatch <var>notification event</var> at the current <a><code>NetworkService</code></a> object.
richt@180
  1366
                        </li>
richt@180
  1367
                     </ol>
richt@180
  1368
                  </li>
richt@180
  1369
richt@180
  1370
               </ol>
richt@180
  1371
richt@180
  1372
            </li>
richt@180
  1373
         </ol>
richt@180
  1374
richt@230
  1375
         <p>
richt@230
  1376
           A <a>user agent</a> can <dfn>terminate an existing UPnP Events Subscription</dfn> at any time for any <var>active service</var> in the <a>list of authorized service records</a> by sending an HTTP UNSUBSCRIBE request - as defined in 'Section 4.1.4: Canceling a subscription with UNSUBSCRIBE' in [[!UPNP-DEVICEARCH11]] - with a HOST header set to that <var>active service</var>'s <code>eventsUrl</code> property and a SID header set to the <var>callback ID</var> obtained when the initial <a>setup a UPnP Events Subscription</a> action occurred.
richt@230
  1377
         </p>
richt@230
  1378
richt@180
  1379
         </section>
richt@180
  1380
richt@180
  1381
         <section>
richt@180
  1382
            <h3>Network Topology Monitoring</h3>
richt@180
  1383
richt@180
  1384
                  <div>
richt@180
  1385
                     <p>
richt@230
  1386
                        When the <a>user agent</a> detects that the user has dropped from their connected network then, for each <var>existing service record</var> in the <a>list of available service records</a>, the user agent
richt@230
  1387
                        <em class="ct">MUST</em>
richt@230
  1388
                            run the general rule for <a>removing an available service</a> passing in each <var>existing service record</var>'s
richt@230
  1389
                            <code>id</code> property as the only argument for each call.
richt@230
  1390
                    </p>
richt@180
  1391
richt@180
  1392
                     <p>
richt@230
  1393
                        When the <a>user agent</a> detects that the user has connected to a new network or reconnected to an existing network, then it
richt@230
  1394
                        <em class="ct">SHOULD</em> restart its discovery
richt@230
  1395
                         mechanisms as defined in the <a href="#service-discovery">Service Discovery</a> section of this specification, maintaining
richt@230
  1396
                         the existing <a>list of authorized service records</a> currently in use.
richt@180
  1397
                     </p>
richt@180
  1398
                  </div>
richt@180
  1399
         </section>
richt@180
  1400
      </section>
richt@180
  1401
richt@180
  1402
   <section>
richt@180
  1403
      <h3>Garbage collection</h3>
richt@180
  1404
richt@180
  1405
      <p>
richt@230
  1406
         Only when the user navigates away from the current browsing context can <a><code>NetworkService</code></a> objects be garbage-collected, its records in the <a>entry script origin's URL whitelist</a> be removed and its corresponding entry in the <a>list of authorized service records</a> be removed.
richt@180
  1407
      </p>
richt@180
  1408
richt@180
  1409
   </section>
richt@180
  1410
richt@180
  1411
richt@180
  1412
    <section>
richt@180
  1413
      <h3>Use Cases and Requirements</h3>
richt@180
  1414
richt@180
  1415
      <p>This section covers what the requirements are for this API, as well as illustrates some use cases.</p>
richt@180
  1416
richt@180
  1417
      <ul class="rule">
richt@180
  1418
         <li>
richt@180
  1419
            Once a user has given permission, user agents should provide the ability for Web pages to communicate directly with a Local-networked Service.
richt@180
  1420
            <ul class="rule">
richt@180
  1421
               <li>
richt@180
  1422
                  Example: A web-based TV remote control. A Web page wants to control the current user's TV, changing the programming shown or increasing/decreasing/muting the
richt@180
  1423
                  volume of the Local-networked Device. The Web page requests a service type that is known to be implemented by television sets to which it has the
richt@180
  1424
                  application logic to communicate. Local devices providing the request service types are discovered and presented to the user for authorization. The user selects one
richt@180
  1425
                  or more of the discovered television sets to be accessible to the current Web page and then clicks 'Share'. The Web page can now communicate directly with
richt@180
  1426
                  the user-authorized Local-networked services.
richt@180
  1427
               </li>
richt@180
  1428
            </ul>
richt@180
  1429
         </li>
richt@180
  1430
richt@180
  1431
         <li>
richt@180
  1432
           Web pages should be able to communicate with Local-networked Services using the messaging channel supported by those Devices.
richt@180
  1433
           <ul class="rule">
richt@180
  1434
            <li>
richt@180
  1435
               Example: A Web page advertises that it is capable of controlling multiple Home Media Servers. The user can select their Home Media Server type from a drop-down list, at which point the
richt@180
  1436
               Web page sends a request to the user agent to connect with the associated service type of the Home Media Server. The Media Server selected implements a Web Socket channel for
richt@180
  1437
               bi-directional service communication and so the Web page opens a web socket to the requested Media Server and can communicate as required via that appropriate channel.
richt@180
  1438
            </li>
richt@180
  1439
           </ul>
richt@180
  1440
         </li>
richt@180
  1441
richt@180
  1442
         <li>
richt@180
  1443
           Web pages should be able to communicate with Local-networked Services using the messaging format supported by those Devices.
richt@180
  1444
           <ul class="rule">
richt@180
  1445
            <li>
richt@180
  1446
               Example: A Web page advertises that it is capable of interacting with and controlling multiple types of Home Media Server. The user can select their Home Media Server type from a drop-down list or known Media Servers, at which point the
richt@180
  1447
               Web page sends a request to the user agent to connect with the associated service type (and, optionally, the associated event type) of the Home Media Server. The communiciation protocols supported by Home Media Servers typically vary
richt@180
  1448
               between UPnP, JSON-RPC, Protocol Buffers or other messaging formats depending on the Home Media Server requested. The Web page is able to communicate with the user-selected Home Media
richt@180
  1449
               Server in the messaging format supported by that Device, which, in this example is a simple key/value pair text format.
richt@180
  1450
            </li>
richt@180
  1451
           </ul>
richt@180
  1452
         </li>
richt@180
  1453
richt@180
  1454
         <li>
richt@180
  1455
           Web pages should not be able to communicate with Local-networked Services that have not been authorized by the user thereby maintaining the user's privacy.
richt@180
  1456
           <ul class="rule">
richt@180
  1457
            <li>
richt@180
  1458
               Example: A Web page requests access to one type of Local-networked service. The user authorizes access to that particular service. Other services running on that same device, and on other devices
richt@180
  1459
               within the network, should not be accessible to the current Web page.
richt@180
  1460
            </li>
richt@180
  1461
           </ul>
richt@180
  1462
         </li>
richt@180
  1463
richt@180
  1464
         <li>
richt@180
  1465
           A user should be able to share one or more Local-networked Services based on a particular service type request from a Web page.
richt@180
  1466
           <ul class="rule">
richt@180
  1467
            <li>
richt@180
  1468
               Example: A Web page is capable of interacting with a specific profile of Local-networked Service. As such, it makes a request to the user agent to access those services, of which multiple matches
richt@180
  1469
               are found. The user is capable of selecting one or more of the discovered services to share with the Web page. The Web page can then implement a drag-and-drop interface for the user to drag specific
richt@180
  1470
               actions on to one or more of the authorized Local-networked Services.
richt@180
  1471
            </li>
richt@180
  1472
           </ul>
richt@180
  1473
         </li>
richt@180
  1474
richt@180
  1475
         <li>
richt@180
  1476
           User agents should provide an API exposed to script that exposes the features above. The user is notified by UI anytime interaction with Local-networked Services is requested, giving the user
richt@180
  1477
           full ability to cancel or abort the transaction. The user selects the Local-networked Services to be connected to the current Web page, and can cancel these at any time. No invocations to
richt@180
  1478
           these APIs occur silently without user intervention.
richt@180
  1479
         </li>
richt@180
  1480
      </ul>
richt@180
  1481
    </section>
richt@180
  1482
richt@180
  1483
          <section class="informative appendix">
richt@180
  1484
             <h3>Examples</h3>
richt@180
  1485
richt@180
  1486
           <div class="example">
richt@180
  1487
            <p>This sample code exposes a button. When clicked, this button is disabled and the user is prompted to offer a network service. The user may also select multiple network services. When the user has authorized a network service to be connected to the web page then the web page issues a simple command to get a list of all the albums stored on the connected media player service.
richt@180
  1488
            <p>The button is re-enabled only when the connected network service disconnects for whatever reason (the service becomes unavailable on the network, the user disconnects from their current network or the user revokes access to the service from the current web page). At this point the user can re-click the button to select a new network service to connect to the web page and the above steps are repeated.</p>
richt@180
  1489
            <p>The provided service type identifier and service interaction used in this example is based on the well-defined service type and messaging format supported by the <a href="http://xbmc.org/about/">XBMC Media Server</a>. </p>
richt@180
  1490
            <hr />
robin@185
  1491
            <pre class="highlight">&lt;input type="button" value="Start" onclick="start()" id="startBtn"/&gt;
richt@180
  1492
&lt;div id="debugconsole">&lt;/div>
richt@180
  1493
richt@180
  1494
&lt;script>
richt@180
  1495
 var startBtn = document.getElementById('startBtn'),
richt@180
  1496
     debug = document.getElementById('debugconsole');
richt@180
  1497
richt@180
  1498
 function start() {
richt@180
  1499
   if(navigator.getNetworkServices) {
richt@180
  1500
      navigator.getNetworkServices('zeroconf:_xbmc-jsonrpc._tcp', gotXBMCService, error);
richt@180
  1501
      startBtn.disabled = true;
richt@180
  1502
   } else {
richt@191
  1503
      debug.innerHTML += "&lt;br&gt;Service Discovery not supported!";
richt@180
  1504
   }
richt@180
  1505
 }
richt@180
  1506
richt@180
  1507
 function gotXBMCService(services) {
richt@180
  1508
richt@180
  1509
// Listen for service disconnect messages
richt@180
  1510
richt@191
  1511
   services[0].addEventListener('serviceoffline', function ( e ) {
richt@180
  1512
       debug.innerHTML += "&lt;br>" + services[0].name + " disconnected.";
richt@180
  1513
       startBtn.disabled = false;
richt@180
  1514
   }, false);
richt@180
  1515
richt@180
  1516
// Send a service message to get albums list (and process the service response)
richt@180
  1517
richt@180
  1518
   var svcXhr = new XMLHttpRequest();
richt@180
  1519
   svcXhr.open("POST", services[0].url + "/getAlbums"); // services[0].url and its subresources have been
richt@180
  1520
                                                        // whitelisted for cross-site XHR use in this
richt@180
  1521
                                                        // current browsing context.
richt@180
  1522
richt@180
  1523
   svcXhr.setRequestHeader('Content-Type', 'application/json-rpc');
richt@180
  1524
richt@180
  1525
   svcXhr.addEventListener('readystatechange', function ( response ) {
richt@180
  1526
     if( response.readyState != 4 || response.status != 200 )
richt@180
  1527
        return;
richt@180
  1528
     debug.innerHTML += "&lt;br>" + services[0].name + " response received: ";
richt@180
  1529
     debug.textContent += JSON.parse(response.responseText);
richt@180
  1530
   }, false);
richt@180
  1531
richt@180
  1532
   var svcMsg = [
richt@180
  1533
     { "jsonrpc": "2.0", "method": "AudioLibrary.GetAlbums", "params": { "genreid": -1,
richt@180
  1534
         "artistid": -1, "start": -1, "end": -1 }, "id": "1" }
richt@180
  1535
   ];
richt@180
  1536
richt@180
  1537
   svcXhr.send(JSON.stringify(svcMsg));
richt@180
  1538
   debug.innerHTML += "&lt;br>" + services[0].name + " request sent: ";
richt@180
  1539
   debug.textContent += JSON.stringify(svcMsg);
richt@180
  1540
richt@180
  1541
 }
richt@180
  1542
richt@180
  1543
 function error( err ) {
richt@180
  1544
   debug.innerHTML += "&lt;br>An error occurred obtaining a local network service.";
richt@180
  1545
   startBtn.disabled = false;
richt@180
  1546
 }
richt@180
  1547
&lt;/script></pre>
richt@180
  1548
           </div>
richt@180
  1549
richt@180
  1550
           <div class="example">
richt@180
  1551
            <p>
richt@180
  1552
             This sample exposes a drop-down list containing a number of common Home-based audio devices. When the user selects an audio device from the list provided, they are prompted to authorize a network service
richt@180
  1553
             based on the service type requested. The user may also select multiple network services matching the selected service type.
richt@180
  1554
             In this example, the user selects their make as being <var>Sony</var> and their model as being <var>Bravia S1000</var> from which the Web page can derive a service type
richt@180
  1555
             (<var>urn:schemas-upnp-org:service:RenderingControl:1</var>).
richt@180
  1556
             <br /><br />Once the user has authorized the device, the web page sends a simple mute command according to the messaging format supported by the device.
richt@180
  1557
            </p>
richt@180
  1558
            <hr />
robin@185
  1559
            <pre class="highlight">&lt;select name="make" id="make"&gt;
richt@180
  1560
  &lt;option selected="selected" disabled="disabled"&gt;Select make&lt;/option&gt;
richt@180
  1561
  &lt;option&gt;Sony&lt;/option&gt;
richt@180
  1562
  &lt;option&gt;Philips&lt;/option&gt;
richt@180
  1563
  &lt;option&gt;Alba&lt;/option&gt;
richt@180
  1564
&lt;/select&gt;
richt@180
  1565
&lt;select name="model" id="model"&gt;&lt;/select&gt;
richt@180
  1566
&lt;div id="debugconsole"&gt;&lt;/div&gt;
richt@180
  1567
richt@180
  1568
&lt;script&gt;
richt@180
  1569
  var debug = document.getElementById('debugconsole');
richt@180
  1570
richt@180
  1571
  var models = {
richt@180
  1572
    "Sony": [
richt@180
  1573
      {"name": "Bravia TV S1000", "type": "upnp", "service": "urn:schemas-upnp-org:service:RenderingControl:1" },
richt@180
  1574
      {"name": "Bravia TV S2000", "type": "zeroconf", "service": "_mediarenderer._http._tcp" },
richt@180
  1575
      {"name": "HiFi WD10", "type": "upnp", "service": "urn:schemas-upnp-org:service:RenderingControl:1" }
richt@180
  1576
    ],
richt@180
  1577
    "Philips": [ /* ... */ ],
richt@180
  1578
    "Alba": [ /* ... */ ]
richt@180
  1579
  };
richt@180
  1580
richt@180
  1581
  var makeEl = document.getElementById("make"),
richt@180
  1582
      modelEl = document.getElementById("model");
richt@180
  1583
richt@180
  1584
  makeEl.addEventListener('change', function() {
richt@180
  1585
    modelEl.innerHTML = ""; // reset
richt@180
  1586
    var defaultOption = document.createElement("option");
richt@180
  1587
    defaultOption.textContent = "Select model";
richt@180
  1588
    defaultOption.setAttribute("disabled", "disabled");
richt@180
  1589
    defaultOption.setAttribute("selected", "selected");
richt@180
  1590
    modelEl.appendChild(defaultOption);
richt@180
  1591
    for(var i = 0, l = models[makeEl.value].length; i < l; i++) {
richt@180
  1592
      var option = document.createElement("option");
richt@180
  1593
      option.textContent = models[makeEl.value][i]["name"];
richt@180
  1594
      option.setAttribute("value", models[makeEl.value][i]["type"] + ":" + models[makeEl.value][i]["service"]);
richt@180
  1595
      modelEl.appendChild(option);
richt@180
  1596
    }
richt@180
  1597
  }, false);
richt@180
  1598
richt@180
  1599
  modelEl.addEventListener('change', function() {
richt@180
  1600
    if(navigator.getNetworkServices &&
richt@180
  1601
         modelEl.value == "upnp:urn:schemas-upnp-org:service:RenderingControl:1") {
richt@180
  1602
      navigator.getNetworkServices(modelEl.value, successCallback, errorCallback);
richt@180
  1603
    } else if (modelEl.value == "zeroconf:_mediarenderer._http._tcp") {
richt@180
  1604
      debug.innerHTML += "&lt;br&gt;Service type is not implemented by this application.";
richt@180
  1605
    } else {
richt@180
  1606
      debug.innerHTML += "&lt;br&gt;Service Discovery is not supported!";
richt@180
  1607
    }
richt@180
  1608
  }, false);
richt@180
  1609
&lt;/script&gt;
richt@180
  1610
richt@180
  1611
&lt;script&gt;
richt@180
  1612
  function successCallback( services ) {
richt@180
  1613
richt@191
  1614
  // Listen for service push notification messages
richt@180
  1615
richt@191
  1616
    services[0].addEventListener('notify', function ( msg ) {
richt@180
  1617
         debug.innerHTML += "&lt;br>" + services[0].name + " event received: ";
richt@180
  1618
         debug.textContent += msg.data;
richt@180
  1619
    }, false);
richt@180
  1620
richt@180
  1621
 // Send a control signal to mute the service audio
richt@180
  1622
richt@180
  1623
    var svcXhr = new XMLHttpRequest();
richt@180
  1624
    svcXhr.open("POST", services[0].url); // services[0].url and its
richt@180
  1625
                                          // subresources have been whitelisted for
richt@180
  1626
                                          // cross-site XHR use in this current
richt@180
  1627
                                          // browsing context.
richt@180
  1628
richt@180
  1629
    svcXhr.setRequestHeader('SOAPAction', 'urn:schemas-upnp-org:service:RenderingControl:1#SetMute');
richt@180
  1630
    svcXhr.setRequestHeader('Content-Type', 'text/xml; charset="utf-8";');
richt@180
  1631
richt@180
  1632
    svcXhr.onreadystatechange = function ( response ) {
richt@180
  1633
      if( response.readyState != 4 || response.status != 200 )
richt@180
  1634
        return;
richt@180
  1635
      debug.innerHTML += "&lt;br&gt;" + services[0].name + " response received: ";
richt@180
  1636
      debug.textContent += response.responseXML;
richt@180
  1637
    }
richt@180
  1638
richt@180
  1639
    // Service messaging to mute the provided service
richt@180
  1640
    var svcMsg = '&lt;?xml version="1.0" encoding="utf-8"?&gt;' +
richt@180
  1641
                 '&lt;s:Envelope s:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/" ' +
richt@180
  1642
                   'xmlns:s="http://schemas.xmlsoap.org/soap/envelope/"&gt;' +
richt@180
  1643
                   '&lt;s:Body&gt;' +
richt@180
  1644
                     '&lt;u:SetMute xmlns:u="urn:schemas-upnp-org:service:RenderingControl:1"&gt;' +
richt@180
  1645
                       '&lt;InstanceID&gt;0&lt;/InstanceID&gt;' +
richt@180
  1646
                       '&lt;Channel&gt;Master&lt;/Channel&gt;' +
richt@180
  1647
                       '&lt;DesiredMute&gt;true&lt;/DesiredMute&gt;' +
richt@180
  1648
                     '&lt;/u:SetMute&gt;' +
richt@180
  1649
                   '&lt;/s:Body&gt;' +
richt@180
  1650
                 '&lt;/s:Envelope&gt;';
richt@180
  1651
richt@180
  1652
    svcXhr.send(svcMsg);
richt@180
  1653
    debug.innerHTML += "&lt;br&gt;" + services[0].name + " request sent: ";
richt@180
  1654
    debug.textContent += svcMsg;
richt@180
  1655
  }
richt@180
  1656
richt@180
  1657
  function errorCallback( error ) {
richt@180
  1658
    debug.innerHTML += "&lt;br&gt;An error occurred: " + error.code;
richt@180
  1659
  }
richt@180
  1660
&lt;/script&gt;</pre>
richt@180
  1661
          </div>
richt@180
  1662
richt@180
  1663
       </section>
richt@180
  1664
richt@180
  1665
    <section>
richt@180
  1666
      <h3>Acknowledgements</h3>
richt@180
  1667
richt@180
  1668
      <p>Thanks are expressed by the editor to the following individuals for their feedback on this specification to date (in alphabetical order):
richt@180
  1669
      <br /><br />
richt@191
  1670
      Gar Bergstedt, Lars-Erik Bolstad, Cathy Chan, Hari G Kumar, Bob Lund, Giuseppe Pascale, Marcin Simonides, Clarke Stevens, Christian S&ouml;derstr&ouml;m, Mark Vickers, ...</p>
richt@180
  1671
richt@180
  1672
      <p>Thanks are also expressed by the editor to the following organizations and groups for their support in producing this specification to date (in alphabetical order):
richt@180
  1673
      <br /></br />
richt@180
  1674
      CableLabs, Opera Software ASA, W3C Device APIs Working Group, W3C Web and TV Interest Group, ...</p>
richt@180
  1675
    </section>
richt@180
  1676
</body>
richt@180
  1677
</html>