discovery-api/Overview.src.html
author Rich Tibbett <richt@opera.com>
Tue, 25 Sep 2012 13:33:45 +0200
changeset 231 a0e6b501258d
parent 230 3c13dc93cfb1
child 232 32487cf058c5
permissions -rw-r--r--
Updates to Service Discovery & Messaging according to feedback @ http://lists.w3.org/Archives/Public/public-device-apis/2012Aug/0095.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@231
   429
               Set <var>services manager</var>'s <a href="#dom-networkservices-servicesavailable"><code>servicesAvailable</code></a> attribute to the number of services currently found in the <a>list of available service records</a> whose <code>type</code> property matches any of the tokens requested in <var>requested control types</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@231
   562
              Returns the current number of services matching one of the app-requested <a>valid service type</a> tokens in the
richt@231
   563
              <a>list of available service records</a>.
richt@180
   564
            </p>
richt@180
   565
          </dd>
richt@180
   566
        </dl>
richt@180
   567
richt@180
   568
        <div>
richt@180
   569
           <p>
richt@230
   570
              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
   571
           </p>
richt@180
   572
richt@180
   573
           <p>
richt@231
   574
              The <dfn id="dom-networkservices-servicesavailable"><code>servicesAvailable</code></dfn> attribute MUST return the number of services in the <a>list of available service records</a> whose <code>type</code> attribute matches any of the <a>valid service type</a> tokens 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
        </div>
richt@180
   578
richt@180
   579
      </section>
richt@180
   580
richt@180
   581
      <section>
richt@180
   582
      <h2>Methods</h2>
richt@180
   583
        <dl class="domintro">
richt@180
   584
        <dt>
richt@180
   585
          <code title="networkservices-getter">
richt@180
   586
            <a href="#networkservices">services</a>
richt@180
   587
          </code>
richt@180
   588
          [
richt@180
   589
          <var title="">index</var>
richt@180
   590
          ]
richt@180
   591
        </dt>
richt@180
   592
        <dd>
richt@180
   593
          <p>
richt@180
   594
            Returns the specified <a href="#networkservice"><code>NetworkService</code></a> object.
richt@180
   595
          </p>
richt@180
   596
        </dd>
richt@180
   597
        <dt>
richt@180
   598
          <code title="networkservices-getter">
richt@180
   599
            <a href="#networkservices">services</a>
richt@180
   600
          </code>
richt@180
   601
          .
richt@180
   602
          <code title="dom-networkservices-getservicebyid">
richt@180
   603
            <a href="#dom-networkservices-getservicebyid">getServiceById</a>
richt@180
   604
          </code>
richt@180
   605
          (
richt@180
   606
          <var title="">id</var>
richt@180
   607
          )
richt@180
   608
        </dt>
richt@180
   609
        <dd>
richt@180
   610
          <p>
richt@180
   611
            Returns the <a href="#networkservice"><code>NetworkService</code></a> object with the given identifier, or null if no
richt@180
   612
            service has that identifier.
richt@180
   613
          </p>
richt@180
   614
        </dd>
richt@180
   615
      </dl>
richt@180
   616
richt@180
   617
      <p>
richt@230
   618
        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
   619
      </p>
richt@180
   620
richt@180
   621
      <p class="note">
richt@230
   622
        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
   623
      </p>
richt@180
   624
richt@180
   625
      <p>
richt@230
   626
        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
   627
      </p>
richt@180
   628
richt@180
   629
      <p>
richt@230
   630
        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
   631
      </p>
richt@180
   632
richt@180
   633
      <p>
richt@230
   634
        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
   635
        When no services in the <a>list of authorized service records</a> match the given argument, the method MUST return null.
richt@180
   636
      </p>
richt@180
   637
richt@180
   638
      <p>
richt@180
   639
         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
   640
         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
   641
         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
   642
      </p>
richt@180
   643
richt@180
   644
      </section>
richt@180
   645
richt@180
   646
      <section>
richt@180
   647
      <h2>Events</h2>
richt@180
   648
richt@180
   649
      <p>
richt@180
   650
         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
   651
       </p>
richt@180
   652
richt@180
   653
       <table border="1">
richt@180
   654
        <thead>
richt@180
   655
          <tr>
richt@180
   656
            <th>
richt@180
   657
              <span title="event handlers">Event handler</span>
richt@180
   658
            </th>
richt@180
   659
            <th>
richt@180
   660
              <span>Event handler event type</span>
richt@180
   661
            </th>
richt@180
   662
          </tr>
richt@180
   663
        </thead>
richt@180
   664
        <tbody>
richt@180
   665
          <tr>
richt@180
   666
            <td>
richt@180
   667
              <dfn id="dom-networkservices-onserviceavailable" title="dom-NetworkServices-onserviceavailable">
richt@180
   668
                <code>onserviceavailable</code>
richt@180
   669
              </dfn>
richt@180
   670
            </td>
richt@180
   671
            <td>
richt@180
   672
              <code title="event-serviceavailable">serviceavailable</code>
richt@180
   673
            </td>
richt@180
   674
          </tr>
richt@180
   675
          <tr>
richt@180
   676
            <td>
richt@180
   677
              <dfn id="dom-networkservices-onserviceunavailable" title="dom-NetworkServices-onserviceunavailable">
richt@180
   678
                <code>onserviceunavailable</code>
richt@180
   679
              </dfn>
richt@180
   680
            </td>
richt@180
   681
            <td>
richt@180
   682
              <code title="event-serviceunavailable">serviceunavailable</code>
richt@180
   683
            </td>
richt@180
   684
          </tr>
richt@180
   685
        </tbody>
richt@180
   686
      </table>
richt@180
   687
richt@180
   688
      <p>
richt@180
   689
         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
   690
      </p>
richt@180
   691
richt@180
   692
      </section>
richt@180
   693
richt@180
   694
    </section>
richt@180
   695
    <section>
richt@180
   696
    <h2>Communicating with a networked service</h3>
richt@180
   697
richt@180
   698
<p>
richt@180
   699
   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
   700
</p>
richt@180
   701
richt@180
   702
<pre class="widl">
richt@180
   703
[NoInterfaceObject]
richt@180
   704
interface <dfn id="networkservice">NetworkService</dfn> {
richt@180
   705
  readonly attribute DOMString        <a href="#dom-networkservice-id">id</a>;
richt@180
   706
  readonly attribute DOMString        <a href="#dom-networkservice-name">name</a>;
richt@180
   707
  readonly attribute DOMString        <a href="#dom-networkservice-type">type</a>;
richt@180
   708
  readonly attribute DOMString        <a href="#dom-networkservice-url">url</a>;
richt@180
   709
  readonly attribute DOMString        <a href="#dom-networkservice-config">config</a>;
richt@180
   710
richt@191
   711
  readonly attribute boolean          <a href="#dom-networkservice-online">online</a>;
richt@180
   712
richt@180
   713
  // event handler attributes
richt@191
   714
           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
   715
           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
   716
richt@191
   717
           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
   718
};
richt@180
   719
richt@180
   720
<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
   721
</pre>
richt@180
   722
richt@180
   723
<section>
richt@180
   724
  <h2>Attributes</h2>
richt@180
   725
richt@180
   726
      <dl class="domintro">
richt@180
   727
        <dt>
richt@180
   728
          <var title="">service</var>
richt@180
   729
           .
richt@180
   730
          <code title="dom-networkservice-id">
richt@180
   731
            <a href="#dom-networkservice-id">id</a>
richt@180
   732
          </code>
richt@180
   733
        </dt>
richt@180
   734
        <dd>
richt@180
   735
          <p>
richt@180
   736
            A unique identifier for the given user-selected service instance.
richt@180
   737
          </p>
richt@180
   738
        </dd>
richt@180
   739
        <dt>
richt@180
   740
          <var title="">service</var>
richt@180
   741
           .
richt@180
   742
          <code title="dom-networkservice-name">
richt@180
   743
            <a href="#dom-networkservice-name">name</a>
richt@180
   744
          </code>
richt@180
   745
        </dt>
richt@180
   746
        <dd>
richt@180
   747
          <p>
richt@180
   748
            The name of the user-selected service.
richt@180
   749
          </p>
richt@180
   750
        </dd>
richt@180
   751
        <dt>
richt@180
   752
          <var title="">service</var>
richt@180
   753
           .
richt@180
   754
          <code title="dom-networkservice-type">
richt@180
   755
            <a href="#dom-networkservice-type">type</a>
richt@180
   756
          </code>
richt@180
   757
        </dt>
richt@180
   758
        <dd>
richt@180
   759
          <p>
richt@180
   760
            The <a>valid service type</a> token value of the user-selected service.
richt@180
   761
          </p>
richt@180
   762
        </dd>
richt@180
   763
        <dt>
richt@180
   764
          <var title="">service</var>
richt@180
   765
           .
richt@180
   766
          <code title="dom-networkservice-url">
richt@180
   767
            <a href="#dom-networkservice-url">url</a>
richt@180
   768
          </code>
richt@180
   769
        </dt>
richt@180
   770
        <dd>
richt@180
   771
          <p>
richt@180
   772
            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
   773
          </p>
richt@180
   774
        </dd>
richt@180
   775
        <dt>
richt@180
   776
          <var title="">service</var>
richt@180
   777
           .
richt@180
   778
          <code title="dom-networkservice-config">
richt@180
   779
            <a href="#dom-networkservice-config">config</a>
richt@180
   780
          </code>
richt@180
   781
        </dt>
richt@180
   782
        <dd>
richt@180
   783
          <p>
richt@180
   784
            The configuration information associated with the service depending on the requested service type.
richt@180
   785
          </p>
richt@180
   786
        </dd>
richt@180
   787
      </dl>
richt@180
   788
richt@180
   789
          <p>
richt@197
   790
            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
   791
         </p>
richt@180
   792
richt@180
   793
         <p>
richt@180
   794
            The <dfn id="dom-networkservice-name"><code>name</code></dfn> attribute represents a human-readable title for the service.
richt@180
   795
         </p>
richt@180
   796
richt@180
   797
         <p>
richt@180
   798
             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
   799
          </p>
richt@180
   800
richt@180
   801
         <p>
richt@180
   802
            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
   803
            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
   804
         </p>
richt@180
   805
richt@180
   806
         <p>
richt@180
   807
            The <dfn id="dom-networkservice-config"><code>config</code></dfn> attribute provides the raw configuration information extracted from the given network service.
richt@180
   808
         </p>
richt@180
   809
richt@180
   810
      </section>
richt@180
   811
richt@180
   812
      <section>
richt@180
   813
         <h3>States</h3>
richt@180
   814
richt@180
   815
      <dl class="domintro">
richt@180
   816
        <dt>
richt@180
   817
          <var title="">service</var>
richt@180
   818
           .
richt@191
   819
          <code title="dom-networkservice-online">
richt@191
   820
            <a href="#dom-networkservice-online">online</a>
richt@180
   821
          </code>
richt@180
   822
        </dt>
richt@180
   823
        <dd>
richt@180
   824
          <p>
richt@191
   825
            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
   826
          </p>
richt@180
   827
        </dd>
richt@180
   828
      </dl>
richt@180
   829
richt@191
   830
      <p>
richt@195
   831
        The <dfn id="dom-networkservice-online"><code>online</code></dfn> attribute indicates whether the service is reporting itself as being
richt@191
   832
        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
   833
      </p>
richt@180
   834
richt@180
   835
      </section>
richt@180
   836
richt@180
   837
      <section>
richt@180
   838
         <h3>Events</h3>
richt@180
   839
richt@180
   840
      <p>
richt@180
   841
         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
   842
         <a href="#networkservice"><code>NetworkService</code></a> interface:
richt@180
   843
       </p>
richt@180
   844
richt@180
   845
       <table border="1">
richt@180
   846
        <thead>
richt@180
   847
          <tr>
richt@180
   848
            <th>
richt@180
   849
              <span title="event handlers">Event handler</span>
richt@180
   850
            </th>
richt@180
   851
            <th>
richt@180
   852
              <span>Event handler event type</span>
richt@180
   853
            </th>
richt@180
   854
          </tr>
richt@180
   855
        </thead>
richt@180
   856
        <tbody>
richt@180
   857
          <tr>
richt@180
   858
            <td>
richt@191
   859
              <dfn id="dom-networkservice-onnotify" title="dom-NetworkService-onnotify">
richt@191
   860
                <code>onnotify</code>
richt@180
   861
              </dfn>
richt@180
   862
            </td>
richt@180
   863
            <td>
richt@191
   864
              <code title="event-notify">notify</code>
richt@180
   865
            </td>
richt@180
   866
          </tr>
richt@180
   867
          <tr>
richt@180
   868
            <td>
richt@191
   869
              <dfn id="dom-networkservice-onserviceonline" title="dom-NetworkService-onserviceonline">
richt@191
   870
                <code>onserviceonline</code>
richt@180
   871
              </dfn>
richt@180
   872
            </td>
richt@180
   873
            <td>
richt@191
   874
              <code title="event-onserviceonline">serviceonline</code>
richt@191
   875
            </td>
richt@191
   876
          </tr>
richt@191
   877
          <tr>
richt@191
   878
            <td>
richt@195
   879
              <dfn id="dom-networkservice-onserviceoffline" title="dom-NetworkService-onserviceoffline">
richt@191
   880
                <code>onserviceoffline</code>
richt@191
   881
              </dfn>
richt@191
   882
            </td>
richt@191
   883
            <td>
richt@191
   884
              <code title="event-onserviceoffline">serviceoffline</code>
richt@180
   885
            </td>
richt@180
   886
          </tr>
richt@180
   887
        </tbody>
richt@180
   888
      </table>
richt@180
   889
richt@180
   890
      <p>
richt@191
   891
         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
   892
      </p>
richt@180
   893
richt@180
   894
      </section>
richt@180
   895
   </section>
richt@180
   896
richt@180
   897
      <section>
richt@180
   898
            <h2>Service Discovery</h2>
richt@180
   899
richt@180
   900
      <p>
richt@192
   901
         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
   902
         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
   903
      </p>
richt@180
   904
      <p>
richt@180
   905
         This section presents how the results of these two service discovery
richt@230
   906
         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
   907
      </p>
richt@180
   908
richt@180
   909
      <p>
richt@180
   910
         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
   911
         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
   912
         invocation of this API from a Web page).
richt@180
   913
      </p>
richt@180
   914
richt@180
   915
      <p>
richt@230
   916
         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
   917
         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
   918
         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
   919
      </p>
richt@180
   920
richt@230
   921
      <p>
richt@230
   922
        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
   923
        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
   924
         <a href="#dom-navigator-getnetworkservices"><code>getNetworkServices()</code></a> algorithm.
richt@230
   925
      </p>
richt@230
   926
richt@230
   927
      <p>
richt@230
   928
        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
   929
        running the following steps:
richt@230
   930
      </p>
richt@230
   931
richt@230
   932
      <ol class="rule">
richt@230
   933
richt@230
   934
        <li>
richt@230
   935
          Let <var>new service registration flag</var> be <code>true</code>.
richt@230
   936
        </li>
richt@230
   937
richt@230
   938
        <li>
richt@230
   939
           For each <var>existing service record</var> in the current <a>list of available service records</a>, run the following sub-steps:
richt@230
   940
           <ol class="rule">
richt@230
   941
richt@230
   942
             <li>
richt@230
   943
              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
   944
               property then abort any remaining sub-steps and continue at the next available <var>existing service record</var>.
richt@230
   945
             </li>
richt@230
   946
richt@230
   947
             <li>
richt@230
   948
              Set <var>new service registration flag</var> to <code>false</code>.
richt@230
   949
             </li>
richt@230
   950
richt@230
   951
             <li>
richt@230
   952
               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
   953
              <var>network service record</var>.
richt@230
   954
             </li>
richt@230
   955
           </ol>
richt@230
   956
        </li>
richt@230
   957
richt@230
   958
        <li>
richt@230
   959
           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
   960
        </li>
richt@230
   961
richt@230
   962
        <li>
richt@230
   963
          For each <var>active service</var> in the <a>list of authorized service records</a> run the following steps:
richt@230
   964
richt@230
   965
          <ol class="rule">
richt@230
   966
richt@230
   967
            <li>
richt@230
   968
               If <var>network service record</var>'s <code>type</code> property does not equal the current <var>active service</var>'s
richt@230
   969
                <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
   970
            </li>
richt@230
   971
richt@230
   972
            <li>
richt@230
   973
               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
   974
               the current <var>active service</var>
richt@230
   975
                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
   976
                 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
   977
                 which does not bubble, is not cancellable, and has no default action, at the <var>services manager</var> associated with
richt@230
   978
                 the current <var>active service</var> object.
richt@230
   979
            </li>
richt@230
   980
richt@230
   981
            <li>
richt@230
   982
               <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
   983
                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
   984
                 does not bubble, is not cancellable, and has no default action, at the current
richt@230
   985
                <var>active service</var> object.
richt@230
   986
            </li>
richt@230
   987
richt@230
   988
          </ol>
richt@230
   989
richt@230
   990
        </li>
richt@230
   991
richt@230
   992
      </ol>
richt@230
   993
richt@230
   994
richt@230
   995
      <p>
richt@230
   996
        The rule for <dfn>removing an available service</dfn> is the general process of removing a service from the
richt@230
   997
        <a>list of available service records</a>
richt@230
   998
         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
   999
richt@230
  1000
      <ol class="rule">
richt@230
  1001
richt@230
  1002
        <li>
richt@230
  1003
           For each <var>existing service record</var> in the current <a>list of available service records</a>, run the following sub-steps:
richt@230
  1004
           <ol class="rule">
richt@230
  1005
richt@230
  1006
             <li>
richt@230
  1007
              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
  1008
             </li>
richt@230
  1009
richt@230
  1010
             <li>
richt@230
  1011
               If the <var>existing service record</var>'s <code>type</code> property begins with the DOMString "<code>upnp:</code>" and
richt@230
  1012
               <var>existing service record</var>'s <code>eventsURL</code> property is set then run the rule to
richt@230
  1013
               <a>terminate an existing UPnP Events Subscription</a>, if one is currently active (as a result of having previously called
richt@230
  1014
               <a>setup a UPnP Events Subscription</a> against the current <var>existing service record</var>).
richt@230
  1015
             </li>
richt@230
  1016
richt@230
  1017
             <li>
richt@230
  1018
               For each <var>active service</var> in <a>list of authorized service records</a> run the following steps:
richt@230
  1019
richt@230
  1020
               <ol class="rule">
richt@230
  1021
richt@230
  1022
                 <li>
richt@230
  1023
                    If <var>existing service record</var>'s <code>type</code> property does not equal the current <var>active service</var>'s
richt@230
  1024
                     <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
  1025
                 </li>
richt@230
  1026
richt@230
  1027
                 <li>
richt@230
  1028
                    Decrement the <a href="#dom-networkservices-servicesavailable"><code>servicesAvailable</code></a> attribute of the
richt@230
  1029
                    <var>services manager</var> associated with the current <var>active service</var>
richt@230
  1030
                     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
  1031
                      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
  1032
                      which does not bubble, is not cancellable, and has no default action, at the <var>services manager</var> associated with
richt@230
  1033
                      the current <var>active service</var> object.
richt@230
  1034
                 </li>
richt@230
  1035
richt@230
  1036
                 <li>
richt@230
  1037
                    <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
  1038
                     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
  1039
                      does not bubble, is not cancellable, and has no default action, at the current
richt@230
  1040
                     <var>active service</var> object.
richt@230
  1041
                 </li>
richt@230
  1042
richt@230
  1043
               </ol>
richt@230
  1044
richt@230
  1045
             </li>
richt@230
  1046
richt@230
  1047
             <li>
richt@230
  1048
               Remove <var>existing service record</var> from the current <a>list of available service records</a>.
richt@230
  1049
             </li>
richt@230
  1050
richt@230
  1051
           </ol>
richt@230
  1052
        </li>
richt@230
  1053
richt@230
  1054
      </ol>
richt@230
  1055
richt@230
  1056
      <p>
richt@230
  1057
       User agents <em class="ct">SHOULD</em> expire a service record from the <a>list of available service records</a> when its
richt@230
  1058
       <code>expiryTimestamp</code> attribute exceeds the current UTC timestamp. When this condition is met the <a>user agent</a> SHOULD
richt@230
  1059
       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
  1060
       only argument.
richt@230
  1061
      </p>
richt@230
  1062
richt@230
  1063
richt@230
  1064
      <section>
robin@185
  1065
         <h4>Zeroconf (<abbr title="Multicast DNS">mDNS</abbr> + <abbr title="Domain Name System">DNS</abbr>-<abbr title="Service Discovery">SD</abbr>)</h4>
richt@180
  1066
richt@180
  1067
         <p>
robin@185
  1068
            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
  1069
   domain [[!MDNS]], the <a>user agent</a> MUST run the following steps:
richt@180
  1070
         </p>
richt@180
  1071
richt@180
  1072
         <ol class="rule">
richt@180
  1073
richt@180
  1074
            <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
  1075
richt@180
  1076
            <li>For each Object <var>service mDNS response</var> in <var>service mDNS responses</var>, run the following steps:
richt@180
  1077
               <ol>
richt@180
  1078
richt@180
  1079
                  <li>
richt@230
  1080
                     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
  1081
                  </li>
richt@180
  1082
richt@180
  1083
                  <li>
richt@180
  1084
                     Set <var>network service record</var>'s <code>id</code> property to the value of the full PTR Service Instance Name [[!MDNS]].
richt@180
  1085
                  </li>
richt@180
  1086
richt@180
  1087
                  <li>
richt@180
  1088
                     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
  1089
                  </li>
richt@180
  1090
richt@180
  1091
                  <li>
richt@180
  1092
                     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
  1093
                  </li>
richt@180
  1094
richt@180
  1095
                  <li>
richt@180
  1096
                     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
  1097
                  </li>
richt@180
  1098
richt@180
  1099
                  <li>
richt@180
  1100
                     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
  1101
                  </li>
richt@180
  1102
richt@180
  1103
                  <li>
richt@230
  1104
                     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
  1105
                  </li>
richt@180
  1106
richt@180
  1107
                  <li>
richt@230
  1108
                     Run the general rule for <a>adding an available service</a>, passing in the current <var>network service record</var> as the
richt@230
  1109
                     only argument.
richt@180
  1110
                  </li>
richt@180
  1111
richt@180
  1112
            </ol>
richt@180
  1113
           </li>
richt@180
  1114
         </ol>
richt@180
  1115
richt@180
  1116
      </section>
richt@180
  1117
richt@180
  1118
      <section>
robin@185
  1119
         <h5>Universal Plug-and-Play (<abbr title="Universal Plug-and-Play">UPnP</abbr>)</h5>
richt@180
  1120
richt@180
  1121
         <p>
richt@230
  1122
          A user agent that implements UPnP service discovery must issue an <dfn>advertisement for UPnP root devices</dfn> against the user's
richt@230
  1123
          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
  1124
          </p>
richt@230
  1125
richt@230
  1126
          <p>
richt@230
  1127
            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
  1128
         </p>
richt@230
  1129
richt@230
  1130
         <p>
richt@230
  1131
          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
  1132
         </p>
richt@230
  1133
richt@230
  1134
         <p>
richt@230
  1135
          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
  1136
            and port</a> the user agent <em class="ct">MUST</em> run the following steps:
richt@180
  1137
         </p>
richt@180
  1138
richt@180
  1139
         <ol class="rule">
richt@230
  1140
          <li>
richt@230
  1141
            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
  1142
          </li>
richt@180
  1143
richt@230
  1144
          <li>
richt@230
  1145
            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
  1146
          </li>
richt@180
  1147
richt@230
  1148
          <li>
richt@230
  1149
             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
  1150
          </li>
richt@180
  1151
richt@230
  1152
          <li>
richt@230
  1153
            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
  1154
          </li>
richt@180
  1155
richt@230
  1156
          <li>
richt@230
  1157
            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
  1158
          </li>
richt@180
  1159
richt@230
  1160
        </ol>
richt@180
  1161
richt@230
  1162
        <p>
richt@230
  1163
          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
  1164
         </p>
richt@180
  1165
richt@230
  1166
        <ol class="rule">
richt@180
  1167
richt@230
  1168
          <li>
richt@230
  1169
            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
  1170
          </li>
richt@180
  1171
richt@230
  1172
          <li>
richt@230
  1173
             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
  1174
          </li>
richt@180
  1175
richt@230
  1176
          <li>
richt@230
  1177
            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
  1178
          </li>
richt@180
  1179
richt@230
  1180
          <li>
richt@230
  1181
            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
  1182
          </li>
richt@180
  1183
richt@230
  1184
        </ol>
richt@180
  1185
richt@230
  1186
      <p>
richt@230
  1187
        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
  1188
        registering the UPnP services contained therein within the <a>list of available service records</a>.
richt@230
  1189
      </p>
richt@180
  1190
richt@230
  1191
      <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
  1192
         agent <em class="ct">MUST</em> run the following steps:</p>
richt@180
  1193
richt@230
  1194
      <ol class="rule">
richt@180
  1195
richt@230
  1196
          <li>
richt@230
  1197
             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
  1198
             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
  1199
          </li>
richt@180
  1200
richt@230
  1201
          <li>
richt@230
  1202
             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
  1203
          </li>
richt@180
  1204
richt@230
  1205
          <li>
richt@230
  1206
             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
  1207
richt@230
  1208
             <ol class="rule">
richt@230
  1209
richt@230
  1210
                <li>
richt@230
  1211
                   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
  1212
                </li>
richt@230
  1213
richt@230
  1214
                <li>
richt@230
  1215
                   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
  1216
                </li>
richt@230
  1217
richt@230
  1218
                <li>
richt@230
  1219
                   Set <var>network service record</var>'s <code>deviceId</code> property to the value of <var>device identifier</var>.
richt@230
  1220
                </li>
richt@230
  1221
richt@230
  1222
                <li>
richt@230
  1223
                   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
  1224
                </li>
richt@230
  1225
richt@230
  1226
                <li>
richt@230
  1227
                   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
  1228
                </li>
richt@230
  1229
richt@230
  1230
                <li>
richt@230
  1231
                   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
  1232
                </li>
richt@230
  1233
richt@230
  1234
                <li>
richt@230
  1235
                   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
  1236
                </li>
richt@230
  1237
richt@230
  1238
                <li>
richt@230
  1239
                   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
  1240
                </li>
richt@230
  1241
richt@230
  1242
                <li>
richt@230
  1243
                   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
  1244
                </li>
richt@230
  1245
richt@230
  1246
                <li>
richt@230
  1247
                  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
  1248
                </li>
richt@230
  1249
richt@230
  1250
              </ol>
richt@230
  1251
richt@230
  1252
          </ol>
richt@230
  1253
richt@230
  1254
         <p>
richt@230
  1255
           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
  1256
           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
  1257
           This rule takes one argument, <var>device identifier</var>, and consists of running the following steps:
richt@230
  1258
        </p>
richt@230
  1259
richt@230
  1260
         <ol class="rule">
richt@230
  1261
richt@230
  1262
           <li>
richt@230
  1263
              For each <var>existing service record</var> in the current <a>list of available service records</a>, run the following sub-steps:
richt@230
  1264
              <ol class="rule">
richt@230
  1265
richt@230
  1266
                <li>
richt@230
  1267
                 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
  1268
                </li>
richt@230
  1269
richt@230
  1270
                <li>
richt@230
  1271
                  Run the general rule for <a>removing an available service</a> passing in <var>existing service record</var>'s <code>id</code>
richt@230
  1272
                  property as the only argument.
richt@230
  1273
                </li>
richt@230
  1274
richt@230
  1275
              </ol>
richt@230
  1276
           </li>
richt@230
  1277
richt@180
  1278
         </ol>
richt@180
  1279
richt@230
  1280
         <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
  1281
richt@180
  1282
         <ol class="rule">
richt@180
  1283
            <li>
richt@180
  1284
               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
  1285
            </li>
richt@180
  1286
richt@180
  1287
            <li>
richt@180
  1288
               Let <var>callback URL</var> be the value of creating a new <a>user-agent generated callback url</a>.
richt@180
  1289
            </li>
richt@180
  1290
richt@180
  1291
            <li>
richt@230
  1292
               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
  1293
               with a string value of <var>callback URL</var> towards the <var>network service record</var>'s <code>eventsUrl</code> property.
richt@180
  1294
            </li>
richt@180
  1295
richt@180
  1296
            <li>
richt@180
  1297
               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
  1298
            </li>
richt@180
  1299
richt@180
  1300
            <li>
richt@180
  1301
               On receiving a valid 200 OK response, run the following steps:
richt@180
  1302
richt@180
  1303
               <ol class="rule">
richt@180
  1304
                  <li>
richt@180
  1305
                     Let <var>callback ID</var> equal the string value of the first included <em>SID</em> header, if it exists.
richt@180
  1306
                  </li>
richt@180
  1307
                  <li>
richt@230
  1308
                     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
  1309
                  </li>
richt@180
  1310
                  <li>
richt@180
  1311
                     Run the following steps aynchronously and continue to the step labeled <em>listen</em> below.
richt@180
  1312
                  </li>
richt@180
  1313
                  <li>
richt@180
  1314
                     <em>Refresh Subscription</em>: Run the following steps at a set interval (X) within the <a>user agent</a>:
richt@180
  1315
richt@180
  1316
                     <ol class="rule">
richt@180
  1317
                        <li>
richt@180
  1318
                           Let <var>current date</var> equal the current UTC date.
richt@180
  1319
                        </li>
richt@180
  1320
                        <li>
richt@180
  1321
                           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
  1322
                        </li>
richt@180
  1323
                        <li>
richt@230
  1324
                           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
  1325
                        </li>
richt@180
  1326
                        <li>
richt@180
  1327
                           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
  1328
                           responses should cause the <a>user agent</a> to continue from the step labeled <em>refresh subscription</em> above.
richt@180
  1329
                        </li>
richt@180
  1330
                     </ol>
richt@180
  1331
richt@180
  1332
                  </li>
richt@180
  1333
richt@180
  1334
                  <li>
richt@180
  1335
                     <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
  1336
richt@180
  1337
                     <ol class="rule">
richt@180
  1338
                        <li>
richt@180
  1339
                           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
  1340
                        </li>
richt@180
  1341
                        <li>
richt@191
  1342
                          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
  1343
                           which does not bubble, is not cancellable, and has no default action.
richt@180
  1344
                        </li>
richt@180
  1345
                        <li>
richt@191
  1346
                           Let the <code>data</code> attribute of <var>notification event</var> have the DOMString value of <var>content clone</var>.
richt@180
  1347
                        </li>
richt@180
  1348
                        <li>
richt@180
  1349
                           <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
  1350
                            dispatch <var>notification event</var> at the current <a><code>NetworkService</code></a> object.
richt@180
  1351
                        </li>
richt@180
  1352
                     </ol>
richt@180
  1353
                  </li>
richt@180
  1354
richt@180
  1355
               </ol>
richt@180
  1356
richt@180
  1357
            </li>
richt@180
  1358
         </ol>
richt@180
  1359
richt@230
  1360
         <p>
richt@230
  1361
           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
  1362
         </p>
richt@230
  1363
richt@180
  1364
         </section>
richt@180
  1365
richt@180
  1366
         <section>
richt@180
  1367
            <h3>Network Topology Monitoring</h3>
richt@180
  1368
richt@180
  1369
                  <div>
richt@180
  1370
                     <p>
richt@230
  1371
                        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
  1372
                        <em class="ct">MUST</em>
richt@230
  1373
                            run the general rule for <a>removing an available service</a> passing in each <var>existing service record</var>'s
richt@230
  1374
                            <code>id</code> property as the only argument for each call.
richt@230
  1375
                    </p>
richt@180
  1376
richt@180
  1377
                     <p>
richt@230
  1378
                        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
  1379
                        <em class="ct">SHOULD</em> restart its discovery
richt@230
  1380
                         mechanisms as defined in the <a href="#service-discovery">Service Discovery</a> section of this specification, maintaining
richt@230
  1381
                         the existing <a>list of authorized service records</a> currently in use.
richt@180
  1382
                     </p>
richt@180
  1383
                  </div>
richt@180
  1384
         </section>
richt@180
  1385
      </section>
richt@180
  1386
richt@180
  1387
   <section>
richt@180
  1388
      <h3>Garbage collection</h3>
richt@180
  1389
richt@180
  1390
      <p>
richt@230
  1391
         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
  1392
      </p>
richt@180
  1393
richt@180
  1394
   </section>
richt@180
  1395
richt@180
  1396
richt@180
  1397
    <section>
richt@180
  1398
      <h3>Use Cases and Requirements</h3>
richt@180
  1399
richt@180
  1400
      <p>This section covers what the requirements are for this API, as well as illustrates some use cases.</p>
richt@180
  1401
richt@180
  1402
      <ul class="rule">
richt@180
  1403
         <li>
richt@180
  1404
            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
  1405
            <ul class="rule">
richt@180
  1406
               <li>
richt@180
  1407
                  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
  1408
                  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
  1409
                  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
  1410
                  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
  1411
                  the user-authorized Local-networked services.
richt@180
  1412
               </li>
richt@180
  1413
            </ul>
richt@180
  1414
         </li>
richt@180
  1415
richt@180
  1416
         <li>
richt@180
  1417
           Web pages should be able to communicate with Local-networked Services using the messaging channel supported by those Devices.
richt@180
  1418
           <ul class="rule">
richt@180
  1419
            <li>
richt@180
  1420
               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
  1421
               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
  1422
               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
  1423
            </li>
richt@180
  1424
           </ul>
richt@180
  1425
         </li>
richt@180
  1426
richt@180
  1427
         <li>
richt@180
  1428
           Web pages should be able to communicate with Local-networked Services using the messaging format supported by those Devices.
richt@180
  1429
           <ul class="rule">
richt@180
  1430
            <li>
richt@180
  1431
               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
  1432
               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
  1433
               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
  1434
               Server in the messaging format supported by that Device, which, in this example is a simple key/value pair text format.
richt@180
  1435
            </li>
richt@180
  1436
           </ul>
richt@180
  1437
         </li>
richt@180
  1438
richt@180
  1439
         <li>
richt@180
  1440
           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
  1441
           <ul class="rule">
richt@180
  1442
            <li>
richt@180
  1443
               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
  1444
               within the network, should not be accessible to the current Web page.
richt@180
  1445
            </li>
richt@180
  1446
           </ul>
richt@180
  1447
         </li>
richt@180
  1448
richt@180
  1449
         <li>
richt@180
  1450
           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
  1451
           <ul class="rule">
richt@180
  1452
            <li>
richt@180
  1453
               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
  1454
               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
  1455
               actions on to one or more of the authorized Local-networked Services.
richt@180
  1456
            </li>
richt@180
  1457
           </ul>
richt@180
  1458
         </li>
richt@180
  1459
richt@180
  1460
         <li>
richt@180
  1461
           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
  1462
           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
  1463
           these APIs occur silently without user intervention.
richt@180
  1464
         </li>
richt@180
  1465
      </ul>
richt@180
  1466
    </section>
richt@180
  1467
richt@180
  1468
          <section class="informative appendix">
richt@180
  1469
             <h3>Examples</h3>
richt@180
  1470
richt@180
  1471
           <div class="example">
richt@180
  1472
            <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
  1473
            <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
  1474
            <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
  1475
            <hr />
robin@185
  1476
            <pre class="highlight">&lt;input type="button" value="Start" onclick="start()" id="startBtn"/&gt;
richt@180
  1477
&lt;div id="debugconsole">&lt;/div>
richt@180
  1478
richt@180
  1479
&lt;script>
richt@180
  1480
 var startBtn = document.getElementById('startBtn'),
richt@180
  1481
     debug = document.getElementById('debugconsole');
richt@180
  1482
richt@180
  1483
 function start() {
richt@180
  1484
   if(navigator.getNetworkServices) {
richt@180
  1485
      navigator.getNetworkServices('zeroconf:_xbmc-jsonrpc._tcp', gotXBMCService, error);
richt@180
  1486
      startBtn.disabled = true;
richt@180
  1487
   } else {
richt@191
  1488
      debug.innerHTML += "&lt;br&gt;Service Discovery not supported!";
richt@180
  1489
   }
richt@180
  1490
 }
richt@180
  1491
richt@180
  1492
 function gotXBMCService(services) {
richt@180
  1493
richt@180
  1494
// Listen for service disconnect messages
richt@180
  1495
richt@191
  1496
   services[0].addEventListener('serviceoffline', function ( e ) {
richt@180
  1497
       debug.innerHTML += "&lt;br>" + services[0].name + " disconnected.";
richt@180
  1498
       startBtn.disabled = false;
richt@180
  1499
   }, false);
richt@180
  1500
richt@180
  1501
// Send a service message to get albums list (and process the service response)
richt@180
  1502
richt@180
  1503
   var svcXhr = new XMLHttpRequest();
richt@180
  1504
   svcXhr.open("POST", services[0].url + "/getAlbums"); // services[0].url and its subresources have been
richt@180
  1505
                                                        // whitelisted for cross-site XHR use in this
richt@180
  1506
                                                        // current browsing context.
richt@180
  1507
richt@180
  1508
   svcXhr.setRequestHeader('Content-Type', 'application/json-rpc');
richt@180
  1509
richt@180
  1510
   svcXhr.addEventListener('readystatechange', function ( response ) {
richt@180
  1511
     if( response.readyState != 4 || response.status != 200 )
richt@180
  1512
        return;
richt@180
  1513
     debug.innerHTML += "&lt;br>" + services[0].name + " response received: ";
richt@180
  1514
     debug.textContent += JSON.parse(response.responseText);
richt@180
  1515
   }, false);
richt@180
  1516
richt@180
  1517
   var svcMsg = [
richt@180
  1518
     { "jsonrpc": "2.0", "method": "AudioLibrary.GetAlbums", "params": { "genreid": -1,
richt@180
  1519
         "artistid": -1, "start": -1, "end": -1 }, "id": "1" }
richt@180
  1520
   ];
richt@180
  1521
richt@180
  1522
   svcXhr.send(JSON.stringify(svcMsg));
richt@180
  1523
   debug.innerHTML += "&lt;br>" + services[0].name + " request sent: ";
richt@180
  1524
   debug.textContent += JSON.stringify(svcMsg);
richt@180
  1525
richt@180
  1526
 }
richt@180
  1527
richt@180
  1528
 function error( err ) {
richt@180
  1529
   debug.innerHTML += "&lt;br>An error occurred obtaining a local network service.";
richt@180
  1530
   startBtn.disabled = false;
richt@180
  1531
 }
richt@180
  1532
&lt;/script></pre>
richt@180
  1533
           </div>
richt@180
  1534
richt@180
  1535
           <div class="example">
richt@180
  1536
            <p>
richt@180
  1537
             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
  1538
             based on the service type requested. The user may also select multiple network services matching the selected service type.
richt@180
  1539
             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
  1540
             (<var>urn:schemas-upnp-org:service:RenderingControl:1</var>).
richt@180
  1541
             <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
  1542
            </p>
richt@180
  1543
            <hr />
robin@185
  1544
            <pre class="highlight">&lt;select name="make" id="make"&gt;
richt@180
  1545
  &lt;option selected="selected" disabled="disabled"&gt;Select make&lt;/option&gt;
richt@180
  1546
  &lt;option&gt;Sony&lt;/option&gt;
richt@180
  1547
  &lt;option&gt;Philips&lt;/option&gt;
richt@180
  1548
  &lt;option&gt;Alba&lt;/option&gt;
richt@180
  1549
&lt;/select&gt;
richt@180
  1550
&lt;select name="model" id="model"&gt;&lt;/select&gt;
richt@180
  1551
&lt;div id="debugconsole"&gt;&lt;/div&gt;
richt@180
  1552
richt@180
  1553
&lt;script&gt;
richt@180
  1554
  var debug = document.getElementById('debugconsole');
richt@180
  1555
richt@180
  1556
  var models = {
richt@180
  1557
    "Sony": [
richt@180
  1558
      {"name": "Bravia TV S1000", "type": "upnp", "service": "urn:schemas-upnp-org:service:RenderingControl:1" },
richt@180
  1559
      {"name": "Bravia TV S2000", "type": "zeroconf", "service": "_mediarenderer._http._tcp" },
richt@180
  1560
      {"name": "HiFi WD10", "type": "upnp", "service": "urn:schemas-upnp-org:service:RenderingControl:1" }
richt@180
  1561
    ],
richt@180
  1562
    "Philips": [ /* ... */ ],
richt@180
  1563
    "Alba": [ /* ... */ ]
richt@180
  1564
  };
richt@180
  1565
richt@180
  1566
  var makeEl = document.getElementById("make"),
richt@180
  1567
      modelEl = document.getElementById("model");
richt@180
  1568
richt@180
  1569
  makeEl.addEventListener('change', function() {
richt@180
  1570
    modelEl.innerHTML = ""; // reset
richt@180
  1571
    var defaultOption = document.createElement("option");
richt@180
  1572
    defaultOption.textContent = "Select model";
richt@180
  1573
    defaultOption.setAttribute("disabled", "disabled");
richt@180
  1574
    defaultOption.setAttribute("selected", "selected");
richt@180
  1575
    modelEl.appendChild(defaultOption);
richt@180
  1576
    for(var i = 0, l = models[makeEl.value].length; i < l; i++) {
richt@180
  1577
      var option = document.createElement("option");
richt@180
  1578
      option.textContent = models[makeEl.value][i]["name"];
richt@180
  1579
      option.setAttribute("value", models[makeEl.value][i]["type"] + ":" + models[makeEl.value][i]["service"]);
richt@180
  1580
      modelEl.appendChild(option);
richt@180
  1581
    }
richt@180
  1582
  }, false);
richt@180
  1583
richt@180
  1584
  modelEl.addEventListener('change', function() {
richt@180
  1585
    if(navigator.getNetworkServices &&
richt@180
  1586
         modelEl.value == "upnp:urn:schemas-upnp-org:service:RenderingControl:1") {
richt@180
  1587
      navigator.getNetworkServices(modelEl.value, successCallback, errorCallback);
richt@180
  1588
    } else if (modelEl.value == "zeroconf:_mediarenderer._http._tcp") {
richt@180
  1589
      debug.innerHTML += "&lt;br&gt;Service type is not implemented by this application.";
richt@180
  1590
    } else {
richt@180
  1591
      debug.innerHTML += "&lt;br&gt;Service Discovery is not supported!";
richt@180
  1592
    }
richt@180
  1593
  }, false);
richt@180
  1594
&lt;/script&gt;
richt@180
  1595
richt@180
  1596
&lt;script&gt;
richt@180
  1597
  function successCallback( services ) {
richt@180
  1598
richt@191
  1599
  // Listen for service push notification messages
richt@180
  1600
richt@191
  1601
    services[0].addEventListener('notify', function ( msg ) {
richt@180
  1602
         debug.innerHTML += "&lt;br>" + services[0].name + " event received: ";
richt@180
  1603
         debug.textContent += msg.data;
richt@180
  1604
    }, false);
richt@180
  1605
richt@180
  1606
 // Send a control signal to mute the service audio
richt@180
  1607
richt@180
  1608
    var svcXhr = new XMLHttpRequest();
richt@180
  1609
    svcXhr.open("POST", services[0].url); // services[0].url and its
richt@180
  1610
                                          // subresources have been whitelisted for
richt@180
  1611
                                          // cross-site XHR use in this current
richt@180
  1612
                                          // browsing context.
richt@180
  1613
richt@180
  1614
    svcXhr.setRequestHeader('SOAPAction', 'urn:schemas-upnp-org:service:RenderingControl:1#SetMute');
richt@180
  1615
    svcXhr.setRequestHeader('Content-Type', 'text/xml; charset="utf-8";');
richt@180
  1616
richt@180
  1617
    svcXhr.onreadystatechange = function ( response ) {
richt@180
  1618
      if( response.readyState != 4 || response.status != 200 )
richt@180
  1619
        return;
richt@180
  1620
      debug.innerHTML += "&lt;br&gt;" + services[0].name + " response received: ";
richt@180
  1621
      debug.textContent += response.responseXML;
richt@180
  1622
    }
richt@180
  1623
richt@180
  1624
    // Service messaging to mute the provided service
richt@180
  1625
    var svcMsg = '&lt;?xml version="1.0" encoding="utf-8"?&gt;' +
richt@180
  1626
                 '&lt;s:Envelope s:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/" ' +
richt@180
  1627
                   'xmlns:s="http://schemas.xmlsoap.org/soap/envelope/"&gt;' +
richt@180
  1628
                   '&lt;s:Body&gt;' +
richt@180
  1629
                     '&lt;u:SetMute xmlns:u="urn:schemas-upnp-org:service:RenderingControl:1"&gt;' +
richt@180
  1630
                       '&lt;InstanceID&gt;0&lt;/InstanceID&gt;' +
richt@180
  1631
                       '&lt;Channel&gt;Master&lt;/Channel&gt;' +
richt@180
  1632
                       '&lt;DesiredMute&gt;true&lt;/DesiredMute&gt;' +
richt@180
  1633
                     '&lt;/u:SetMute&gt;' +
richt@180
  1634
                   '&lt;/s:Body&gt;' +
richt@180
  1635
                 '&lt;/s:Envelope&gt;';
richt@180
  1636
richt@180
  1637
    svcXhr.send(svcMsg);
richt@180
  1638
    debug.innerHTML += "&lt;br&gt;" + services[0].name + " request sent: ";
richt@180
  1639
    debug.textContent += svcMsg;
richt@180
  1640
  }
richt@180
  1641
richt@180
  1642
  function errorCallback( error ) {
richt@180
  1643
    debug.innerHTML += "&lt;br&gt;An error occurred: " + error.code;
richt@180
  1644
  }
richt@180
  1645
&lt;/script&gt;</pre>
richt@180
  1646
          </div>
richt@180
  1647
richt@180
  1648
       </section>
richt@180
  1649
richt@180
  1650
    <section>
richt@180
  1651
      <h3>Acknowledgements</h3>
richt@180
  1652
richt@180
  1653
      <p>Thanks are expressed by the editor to the following individuals for their feedback on this specification to date (in alphabetical order):
richt@180
  1654
      <br /><br />
richt@191
  1655
      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
  1656
richt@180
  1657
      <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
  1658
      <br /></br />
richt@180
  1659
      CableLabs, Opera Software ASA, W3C Device APIs Working Group, W3C Web and TV Interest Group, ...</p>
richt@180
  1660
    </section>
richt@180
  1661
</body>
richt@180
  1662
</html>