discovery-api/Overview.src.html
author Rich Tibbett <richt@opera.com>
Wed, 22 Aug 2012 15:45:40 +0200
changeset 191 5e0da09685f7
parent 180 ee3a89da06e1
child 192 3ecf12df315d
permissions -rw-r--r--
Discovery API updates following feedback from http://lists.w3.org/Archives/Public/public-device-apis/2012Aug/0016.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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    <!-- This spec has been compiled with ReSpec v2 -->
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    <script type="text/javascript" class='remove'>
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      var respecConfig = {
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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://w3c-test.org/dap/discovery-api/",
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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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          //extraCSS:             ["./css/respec2.css"],
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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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      };
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    </script>
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    <style type="text/css">
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      /**
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       * SyntaxHighlighter
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       * http://alexgorbatchev.com/SyntaxHighlighter
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       *
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       * SyntaxHighlighter is donationware. If you are using it, please donate.
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       * http://alexgorbatchev.com/SyntaxHighlighter/donate.html
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       *
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       * @version
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       * 3.0.83 (July 02 2010)
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       *
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       * @copyright
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       * Copyright (C) 2004-2010 Alex Gorbatchev.
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       *
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       * @license
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       * Dual licensed under the MIT and GPL licenses.
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       */
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    </style>
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    <style type="text/css">
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      /**
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       * SyntaxHighlighter
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       * http://alexgorbatchev.com/SyntaxHighlighter
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       *
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       * SyntaxHighlighter is donationware. If you are using it, please donate.
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       * http://alexgorbatchev.com/SyntaxHighlighter/donate.html
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       *
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       * @version
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       * 3.0.83 (July 02 2010)
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       *
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       * @copyright
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       * Copyright (C) 2004-2010 Alex Gorbatchev.
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       *
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       * @license
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       * Dual licensed under the MIT and GPL licenses.
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       */
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        color: red !important;
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      pre.widl:before { content: "IDL"; font: bold small sans-serif; padding: 0.5em; background: white; position: absolute; top: 0; margin: -1px 0 0 -4em; width: 1.5em; border: thin solid; border-radius: 0 0 0 0.5em }
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      div.example { border: solid thin red; background: #F7DFE5; color: black; padding: 0.5em 1em; position: relative; margin: 1em 0 1em 4.6em; width: auto; }
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      div.example:before { content: "EXAMPLE"; font: bold small sans-serif; padding: 0.5em; background: red; color: white; position: absolute; top: 0; margin: -1px 0 0 -7.6em; width: 5em; border: thin solid red; border-radius: 0 0 0 0.5em }
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      dl.domintro { color: green; margin: 2em 0 2em 2em; padding: 0.5em 1em; border: none; background: #DDFFDD; }
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      hr + dl.domintro, div.impl + dl.domintro { margin-top: 2.5em; margin-bottom: 1.5em; }
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      dl.domintro dt, dl.domintro dt * { color: black; text-decoration: none; }
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      dl.domintro dd { margin: 0.5em 0 1em 2em; padding: 0; }
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      dl.domintro dd p { margin: 0.5em 0; }
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      dl.domintro code {font-size: inherit; font-style: italic; }
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      dl.domintro:before { display: table; margin: -1em -0.5em 0.5em auto; width: auto; content: 'This box is non-normative. Implementation requirements are given below this box.'; color: red; border: solid 2px; background: white; padding: 0 0.25em; }
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    </style>
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  </head>
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   419
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  <body>
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    <section id='abstract'>
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   422
      <p>
richt@180
   423
        This specification defines a mechanism for an HTML document to discover and subsequently communicate with <acronym title="Hypertext Transfer Protocol">HTTP</acronym>-based services
richt@180
   424
        advertised via common discovery protocols within a user's network.
richt@180
   425
      </p>
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   426
    </section>
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   427
richt@180
   428
    <section id='sotd'>
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      <p>
richt@180
   430
        This document represents the early consensus of the group on the scope and features of the proposed
richt@180
   431
        API.
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   432
      </p>
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   433
    </section>
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   434
richt@180
   435
    <section class="informative">
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   436
      <h3>Introduction</h3>
richt@180
   437
richt@180
   438
      <p>To enable Web pages to connect and communicate with Local-networked Services provided over HTTP, this specification introduces the
richt@180
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      <a href="#navigatornetworkservice"><code>NavigatorNetworkService</code></a> interface.</p>
richt@180
   440
richt@180
   441
      <p>
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   442
         Using this <acronym title="Application Programming Interface">API</acronym> 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,
richt@180
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         is expected before the web page is able to interact with any Local-networked Services.
richt@180
   444
      </p>
richt@180
   445
richt@180
   446
      <p>
richt@180
   447
         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.
richt@180
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      </p>
richt@180
   449
richt@180
   450
      <p>
richt@180
   451
         The user agent, having captured all advertised services on the network from the Service Discovery mechanisms included in this recommendation, attempts to match
richt@180
   452
      the requested service type to a discovered service according to the processing described herein.
richt@180
   453
      </p>
richt@180
   454
richt@180
   455
      <p>
richt@180
   456
          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.
richt@180
   457
          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.
richt@180
   458
      </p>
richt@180
   459
richt@180
   460
      <p>
richt@180
   461
         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
richt@180
   462
         authorized via the provided API.
richt@180
   463
         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
richt@180
   464
         connected Local-networked Service.
richt@180
   465
      </p>
richt@180
   466
richt@180
   467
      <div class="example">
richt@180
   468
       <p>Example of requesting a DNS-SD advertised service:</p>
richt@180
   469
       <hr />
richt@180
   470
       <pre class="brush:js">function showServices( services ) {
richt@180
   471
  // Show a list of all the services provided to the web page
richt@180
   472
  for(var i = 0, l = services.length; i < l; i++) console.log( services[i].name );
richt@180
   473
}
richt@180
   474
richt@180
   475
navigator.getNetworkServices('zeroconf:_boxee-jsonrpc._tcp', showServices);</pre>
richt@180
   476
      </div>
richt@180
   477
richt@180
   478
      <div class="example">
richt@180
   479
        <p>Example of requesting a UPnP advertised service, also handling error conditions:</p>
richt@180
   480
        <hr />
richt@180
   481
        <pre class="brush:js">function showServices( services ) {
richt@180
   482
  // Show a list of all the services provided to the web page
richt@180
   483
  for(var i = 0, l = services.length; i < l; i++) console.log( services[i].name );
richt@180
   484
}
richt@180
   485
richt@180
   486
function error( e ) {
richt@180
   487
  console.log( "Error occurred: " + e.code );
richt@180
   488
}
richt@180
   489
richt@180
   490
navigator.getNetworkServices('upnp:urn:schemas-upnp-org:service:ContentDirectory:1', showServices, error);</pre>
richt@180
   491
      </div>
richt@180
   492
richt@180
   493
      <div class="example">
richt@180
   494
        <p>Example of requesting either a DNS-SD or UPnP advertised service:</p>
richt@180
   495
        <hr />
richt@180
   496
        <pre class="brush:js">function showServices( services ) {
richt@180
   497
  // Show a list of all the services provided to the web page (+ service type)
richt@180
   498
  for(var i = 0, l = services.length; i < l; i++)
richt@180
   499
     console.log( services[i].name + '(' + services[i].type + ')' );
richt@180
   500
}
richt@180
   501
richt@180
   502
navigator.getNetworkServices([
richt@180
   503
  'zeroconf:_boxee-jsonrpc._tcp',
richt@180
   504
  'upnp:urn:schemas-upnp-org:service:ContentDirectory:1'
richt@180
   505
], showServices);</pre>
richt@180
   506
      </div>
richt@180
   507
richt@180
   508
      <p>For more detailed examples see the <a href="#examples">Examples</a> section.
richt@180
   509
    </section>
richt@180
   510
richt@180
   511
    <section
richt@180
   512
     id='conformance'>
richt@180
   513
richt@180
   514
     <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
richt@180
   515
     meaning of the key word ("must", "should", "may", etc) used in introducing the algorithm.</p>
richt@180
   516
richt@180
   517
     <p>
richt@180
   518
      Some conformance requirements are phrased as requirements on attributes, methods or objects. Such requirements are to be interpreted as requirements on user agents.
richt@180
   519
     </p>
richt@180
   520
richt@180
   521
     <p>
richt@180
   522
      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
richt@180
   523
      this specification are intended to be easy to follow, and not intended to be performant.)
richt@180
   524
     </p>
richt@180
   525
richt@180
   526
     <p>
richt@180
   527
      The only conformance class defined by this specification is a <dfn>user agent</dfn>.
richt@180
   528
     </p>
richt@180
   529
richt@180
   530
     <p>
richt@180
   531
      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
richt@180
   532
      around platform-specific limitations.
richt@180
   533
     </p>
richt@180
   534
richt@180
   535
     <p>
richt@180
   536
      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
richt@180
   537
      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
richt@180
   538
      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
richt@180
   539
      is insufficient.
richt@180
   540
     </p>
richt@180
   541
richt@180
   542
      <section>
richt@180
   543
         <h3>Dependencies</h3>
richt@180
   544
richt@180
   545
         This specification relies on several other underlying specifications.
richt@180
   546
richt@180
   547
         <dl>
richt@180
   548
            <dt>HTML</dt>
richt@180
   549
            <dd>Many fundamental concepts from HTML are used by this specification. [[!HTML5]]</dd>
richt@180
   550
            <dt>WebIDL</dt>
richt@180
   551
            <dd>The IDL blocks in this specification use the semantics of the WebIDL specification. [[!WEBIDL]]</dd>
richt@180
   552
         </dl>
richt@180
   553
      </section>
richt@180
   554
    </section>
richt@180
   555
richt@180
   556
    <section>
richt@180
   557
      <h3>Terminology</h3>
richt@180
   558
richt@180
   559
      <p>
richt@180
   560
         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>".
richt@180
   561
      </p>
richt@180
   562
richt@180
   563
      <p>
richt@180
   564
         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
richt@180
   565
         other <code>Node</code> objects as defined in the DOM Core specifications. [[!DOM-CORE]]
richt@180
   566
      </p>
richt@180
   567
richt@180
   568
      <p>
richt@180
   569
         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.
richt@180
   570
      </p>
richt@180
   571
richt@180
   572
      <p>
richt@180
   573
        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.
richt@180
   574
      </p>
richt@180
   575
richt@180
   576
      <p>
richt@180
   577
        A <a>valid service type</a> provided in the <code>type</code> attribute of the <code>getNetworkServices()</code> 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.
richt@180
   578
      </p>
richt@180
   579
    </section>
richt@180
   580
richt@180
   581
    <section>
richt@180
   582
     <h2>Requesting networked services</h2>
richt@180
   583
richt@180
   584
richt@180
   585
<pre class="widl">[Supplemental, NoInterfaceObject]
richt@180
   586
interface <dfn id="navigatornetworkservice">NavigatorNetworkService</dfn> {
richt@180
   587
  // Obtain a Local-networked Service
richt@180
   588
  void <a href="#dom-navigator-getnetworkservices">getNetworkServices</a>( in any type,
richt@180
   589
                           in <a href="#navigatornetworkservicesuccesscallback">NavigatorNetworkServiceSuccessCallback</a> successCallback,
richt@180
   590
                           in optional <a href="#navigatornetworkserviceerrorcallback">NavigatorNetworkServiceErrorCallback</a> errorCallback );
richt@180
   591
};
richt@180
   592
<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>;
richt@180
   593
richt@180
   594
[Callback=FunctionOnly, NoInterfaceObject]
richt@180
   595
interface <dfn id="navigatornetworkservicesuccesscallback">NavigatorNetworkServiceSuccessCallback</dfn> {
richt@180
   596
  void handleEvent( in <a href="#networkservices">NetworkServices</a> services );
richt@180
   597
};
richt@180
   598
richt@180
   599
[NoInterfaceObject]
richt@180
   600
interface <dfn id="navigatornetworkserviceerror">NavigatorNetworkServiceError</dfn> {
richt@180
   601
  const unsigned short <a href="#dom-navigatornetworkserviceerror-permission_denied">PERMISSION_DENIED_ERR</a> = 1;
richt@180
   602
  const unsigned short <a href="#dom-navigatornetworkserviceerror-unknown_type_prefix">UNKNOWN_TYPE_PREFIX_ERR</a> = 2;
richt@180
   603
  readonly attribute unsigned short <a href="#dom-navigatornetworkserviceerror-code">code</a>;
richt@180
   604
};
richt@180
   605
richt@180
   606
[Callback=FunctionOnly, NoInterfaceObject]
richt@180
   607
interface <dfn id="navigatornetworkserviceerrorcallback">NavigatorNetworkServiceErrorCallback</dfn> {
richt@180
   608
  void handleEvent( in <a href="#navigatornetworkserviceerror">NavigatorNetworkServiceError</a> error );
richt@180
   609
};
richt@180
   610
</pre>
richt@180
   611
richt@180
   612
  <section>
richt@180
   613
   <h2>Methods</h2>
richt@180
   614
richt@180
   615
      <dl class="domintro">
richt@180
   616
        <dt>
richt@180
   617
          <var title="">window</var>
richt@180
   618
           .
richt@180
   619
          <code title="dom-navigator">
richt@180
   620
            <a href="http://www.whatwg.org/specs/web-apps/current-work/complete/timers.html#navigator">navigator</a>
richt@180
   621
          </code>
richt@180
   622
           .
richt@180
   623
          <code title="dom-navigator-getNetworkServices">
richt@180
   624
            <a href="#dom-navigator-getnetworkservices">getNetworkServices</a>
richt@180
   625
          </code>
richt@180
   626
          (
richt@180
   627
          <var title="">type</var>
richt@180
   628
          ,
richt@180
   629
          <var title="">successCallback</var>
richt@180
   630
           [,
richt@180
   631
          <var title="">errorCallback</var>
richt@180
   632
           ] )
richt@180
   633
        </dt>
richt@180
   634
        <dd>
richt@180
   635
          <p>Prompts the user to select one or more discovered network services that have advertised support for the requested service type.</p>
richt@180
   636
          <p>
richt@180
   637
            The
richt@180
   638
            <var title="">type</var>
richt@180
   639
             argument contains one or more <a>valid service type</a> tokens that the web page would like to interact with.
richt@180
   640
          </p>
richt@180
   641
          <p>
richt@180
   642
            If the user accepts, the
richt@180
   643
            <var title="">successCallback</var>
richt@180
   644
             is
richt@180
   645
          invoked, with one or more
richt@180
   646
            <code>
richt@180
   647
              <a href="#networkservice"><code>NetworkService</code></a>
richt@180
   648
            </code>
richt@180
   649
             objects as
richt@180
   650
          its argument.
richt@180
   651
          </p>
richt@180
   652
          <p>
richt@180
   653
            If the user declines, the
richt@180
   654
            <var title="">errorCallback</var>
richt@180
   655
             (if
richt@180
   656
          any) is invoked.
richt@180
   657
          </p>
richt@180
   658
        </dd>
richt@180
   659
      </dl>
richt@180
   660
richt@180
   661
       <div>
richt@180
   662
          <p>
richt@180
   663
            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:
richt@180
   664
          </p>
richt@180
   665
richt@180
   666
          <ol class="rule">
richt@180
   667
richt@180
   668
            <li>
richt@180
   669
              Let <var>requested control types</var> be initially set to an empty array.
richt@180
   670
            </li>
richt@180
   671
richt@180
   672
            <li>
richt@180
   673
               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.
richt@180
   674
            </li>
richt@180
   675
richt@180
   676
            <li>
richt@180
   677
               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>.
richt@180
   678
            </li>
richt@180
   679
richt@180
   680
            <li>
richt@180
   681
               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
richt@180
   682
                 <a href="#dom-navigatornetworkserviceerror-code"><code>code</code></a> attribute has the numeric value 2
richt@180
   683
                  (<a href="#dom-navigatornetworkserviceerror-unknown_type_prefix"><code>UNKNOWN_TYPE_PREFIX_ERR</code></a>) as its argument,
richt@180
   684
                   abort any remaining steps and return.
richt@180
   685
            </li>
richt@180
   686
richt@180
   687
            <li>
richt@180
   688
               <em>Process</em>: Let <var>services found</var> be an empty array.
richt@180
   689
            </li>
richt@180
   690
richt@180
   691
            <li>
richt@180
   692
               For each <var>available service</var> in the <a>list of available service records</a> run the following steps:
richt@180
   693
               <ol class="rule">
richt@180
   694
                  <li>
richt@180
   695
                    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
   696
                  </li>
richt@180
   697
                  <li>
richt@180
   698
                     Continue at the next <var>available service</var>.
richt@180
   699
                  </li>
richt@180
   700
                  <li>
richt@180
   701
                     <em>Attach</em>: If <var>matched service</var> is not empty then run the following steps:
richt@180
   702
richt@180
   703
                     <ol class="rule">
richt@180
   704
                        <li>
richt@180
   705
                           Let <var>new service object</var> be a new <a href="#networkservice"><code>NetworkService</code></a> object, mapping the parameters of
richt@180
   706
                     <var>matched service</var> to this new object where possible.
richt@180
   707
                        </li>
richt@180
   708
                        <li>
richt@180
   709
                           Append <var>new service object</var> to the <var>services found</var> array.
richt@180
   710
                        </li>
richt@180
   711
                     </ol>
richt@180
   712
                  </li>
richt@180
   713
               </ol>
richt@180
   714
            </li>
richt@180
   715
richt@180
   716
            <li>
richt@180
   717
               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
   718
                 <a href="#dom-navigatornetworkserviceerror-code"><code>code</code></a> attribute has the numeric value 1
richt@180
   719
                 (<a href="#dom-navigatornetworkserviceerror-permission_denied"><code>PERMISSION_DENIED_ERR</code></a>) as its argument, abort any remaining steps and return.
richt@180
   720
            </li>
richt@180
   721
richt@180
   722
            <li>
richt@180
   723
               Return, and run the remaining steps asynchronously.
richt@180
   724
            </li>
richt@180
   725
richt@180
   726
            <li>
richt@180
   727
               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
   728
                 <a href="#dom-navigatornetworkserviceerror-code"><code>code</code></a> attribute has the numeric value 1
richt@180
   729
                 (<a href="#dom-navigatornetworkserviceerror-permission_denied"><code>PERMISSION_DENIED_ERR</code></a>) as its argument, abort any remaining steps and return.
richt@180
   730
            </li>
richt@180
   731
richt@180
   732
            <li>
richt@180
   733
                  The <a>user agent</a> MUST prompt the user in a user-agent-specific manner for permission to provide the
richt@180
   734
                  <a href="http://www.whatwg.org/specs/web-apps/current-work/complete/browsers.html#entry-script" class="externalDFN">entry script</a>'s
richt@180
   735
                  <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
   736
                  <a href="#networkservice"><code>NetworkService</code></a> objects representing the user-authorized subset of <var>services found</var>.
richt@180
   737
richt@180
   738
               <p>
richt@180
   739
                  If the user grants permission to access one or more networked services then the <a>user agent</a> SHOULD include an
richt@180
   740
                  "ongoing local-network communication" indicator.
richt@180
   741
               </p>
richt@180
   742
richt@180
   743
               <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
   744
                <a href="#dom-navigatornetworkserviceerror-code"><code>code</code></a> attribute has the numeric value 1
richt@180
   745
                (<a href="#dom-navigatornetworkserviceerror-permission_denied"><code>PERMISSION_DENIED_ERR</code></a>) as its argument, abort any remaining steps and return.
richt@180
   746
              </p>
richt@180
   747
richt@180
   748
              <p>
richt@180
   749
                If the user never responds, this algorithm stalls on this step.
richt@180
   750
              </p>
richt@180
   751
richt@180
   752
            </li>
richt@180
   753
richt@180
   754
            <li>
richt@180
   755
               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
   756
            </li>
richt@180
   757
richt@180
   758
            <li>
richt@180
   759
               For each Object <var>service</var> in <var>services</var>, run the following substeps:
richt@180
   760
richt@180
   761
               <ol class="rule">
richt@180
   762
                  <li>
richt@180
   763
                     Add the <var>service</var>'s <code>url</code> parameter to the <a>entry script origin's <acronym title="Uniform Resource Locator">URL</acronym> whitelist</a>.
richt@180
   764
                  </li>
richt@180
   765
                  <li>
richt@191
   766
                    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
   767
                  </li>
richt@180
   768
               </ol>
richt@180
   769
            </li>
richt@180
   770
richt@180
   771
            <li>
richt@180
   772
               Let <var>services manager</var> be a new <a href="#networkservices"><code>NetworkServices</code></a> object.
richt@180
   773
            </li>
richt@180
   774
richt@180
   775
            <li>
richt@191
   776
               Set <var>services manager</var>'s <a href="#dom-networkservices-servicesavailable"><code>servicesAvailable</code></a> attribute to the length of <var>services</var>.
richt@180
   777
            </li>
richt@180
   778
richt@180
   779
            <li>
richt@180
   780
              Store the set of <var>services</var> as <dfn id="current_authorized_services">current authorized services</dfn> internally against the newly created <var>services manager</var> object.
richt@180
   781
            </li>
richt@180
   782
richt@180
   783
            <li>
richt@180
   784
               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
   785
               <var>services manager</var> as its argument.
richt@180
   786
            </li>
richt@180
   787
richt@180
   788
          </ol>
richt@180
   789
richt@180
   790
          <p>
richt@180
   791
            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
   792
            <a href="http://www.whatwg.org/specs/web-apps/current-work/complete/webappapis.html#concept-task" class="externalDFN">tasks</a> is the
richt@180
   793
            <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
   794
          </p>
richt@180
   795
richt@180
   796
          <p>
richt@180
   797
            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
   798
             to the <dfn>entry script origin's URL whitelist</dfn>. This list enables the
richt@180
   799
            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
   800
            <a href="http://www.whatwg.org/specs/web-apps/current-work/complete/browsers.html#entry-script" class="externalDFN">entry script</a>'s
richt@180
   801
            <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
   802
            Web Messaging, XMLHttpRequest).
richt@180
   803
         </p>
richt@180
   804
richt@180
   805
         <p>
richt@180
   806
            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
   807
            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
   808
            <ul>
richt@180
   809
              <li>If the current script is reloaded at any point in the same or different window.</li>
richt@180
   810
              <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
   811
              <li>If the user navigates forward or back in their history to reload the current page.</li>
richt@180
   812
              <li>If a script is running in a different origin.</li>
richt@180
   813
            </ul>
richt@180
   814
         </p>
richt@180
   815
richt@180
   816
      </div>
richt@180
   817
      </section>
richt@180
   818
richt@180
   819
      <section>
richt@180
   820
         <h3>Error Handling</h3>
richt@180
   821
richt@180
   822
      <dl class="domintro">
richt@180
   823
        <dt>
richt@180
   824
          <var title="">error</var>
richt@180
   825
           .
richt@180
   826
          <code title="dom-NavigatorNetworkServiceError-code">
richt@180
   827
            <a href="#dom-navigatornetworkserviceerror-code">code</a>
richt@180
   828
          </code>
richt@180
   829
        </dt>
richt@180
   830
        <dd>
richt@180
   831
          <p>
richt@180
   832
            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
   833
            corresponding error constants
richt@180
   834
            <a href="#dom-navigatornetworkserviceerror-permission_denied"><code>PERMISSION_DENIED_ERR</code></a> and
richt@180
   835
            <a href="#dom-navigatornetworkserviceerror-unknown_type_prefix"><code>UNKNOWN_TYPE_PREFIX_ERR</code></a> are defined.
richt@180
   836
          </p>
richt@180
   837
        </dd>
richt@180
   838
      </dl>
richt@180
   839
richt@180
   840
         <p>
richt@180
   841
            The <dfn id="dom-navigatornetworkserviceerror-code" title="dom-navigatornetworkserviceerror-code"><code>code</code></dfn> attribute of a
richt@180
   842
            <a href="#navigatornetworkserviceerror"><code>NavigatorNetworkServiceError</code></a> object MUST return the code for the error, which will be one of the following:
richt@180
   843
         </p>
richt@180
   844
richt@180
   845
         <dl>
richt@180
   846
            <dt>
richt@180
   847
               <dfn id="dom-navigatornetworkserviceerror-permission_denied" title="dom-navigatornetworkserviceerror-permission_denied"><code>PERMISSION_DENIED_ERR</code></dfn> (numeric value 1)
richt@180
   848
            </dt>
richt@180
   849
            <dd>
richt@180
   850
               The user denied the page permission to access any services.
richt@180
   851
            </dd>
richt@180
   852
            <dt>
richt@180
   853
               <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
   854
            </dt>
richt@180
   855
            <dd>
richt@180
   856
               No <a>valid service type</a> tokens were provided in the method invocation.
richt@180
   857
            </dd>
richt@180
   858
         </dl>
richt@180
   859
richt@180
   860
      </section>
richt@180
   861
richt@180
   862
      </section>
richt@180
   863
      <section>
richt@180
   864
      <h2>Obtaining networked services</h2>
richt@180
   865
richt@180
   866
      <p>
richt@180
   867
         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
   868
      </p>
richt@180
   869
richt@180
   870
<pre class="widl">
richt@180
   871
[NoInterfaceObject]
richt@180
   872
interface <dfn id="networkservices">NetworkServices</dfn> {
richt@180
   873
  readonly attribute unsigned long    <a href="#dom-networkservices-length">length</a>;
richt@180
   874
  getter <a href="#networkservice">NetworkService</a> (unsigned long index);
richt@180
   875
  <a href="#networkservice">NetworkService</a>? <a href="#dom-networkservices-getservicebyid">getServiceById</a>(DOMString id);
richt@180
   876
richt@180
   877
  readonly attribute unsigned long    <a href="#dom-networkservices-servicesavailable">servicesAvailable</a>;
richt@180
   878
richt@180
   879
  // event handler attributes
richt@180
   880
           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
   881
           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
   882
richt@180
   883
};
richt@180
   884
richt@180
   885
<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
   886
</pre>
richt@180
   887
richt@180
   888
      <section>
richt@180
   889
      <h2>Attributes</h2>
richt@180
   890
richt@180
   891
        <dl class="domintro">
richt@180
   892
          <dt>
richt@180
   893
            <code title="dom-networkservices-length">
richt@180
   894
              <a href="#dom-networkservices-length">length</a>
richt@180
   895
            </code>
richt@180
   896
          </dt>
richt@180
   897
          <dd>
richt@180
   898
            <p>
richt@180
   899
              Returns the current number of services in the respective object's <a>current authorized services</a>.
richt@180
   900
            </p>
richt@180
   901
          </dd>
richt@180
   902
          <dt>
richt@180
   903
            <code title="dom-networkservices-servicesavailable">
richt@180
   904
              <a href="#dom-networkservices-servicesavailable">servicesAvailable</a>
richt@180
   905
            </code>
richt@180
   906
          </dt>
richt@180
   907
          <dd>
richt@180
   908
            <p>
richt@180
   909
              Returns the current number of services matching one of the app-requested <a>valid service type</a> tokens that are actively available within the user's current network.
richt@180
   910
            </p>
richt@180
   911
          </dd>
richt@180
   912
        </dl>
richt@180
   913
richt@180
   914
        <div>
richt@180
   915
           <p>
richt@180
   916
              The <dfn id="dom-networkservices-length"><code>length</code></dfn> attribute MUST return the number of services represented in the object's corresponding <a>current authorized services</a> list at the time of getting.
richt@180
   917
           </p>
richt@180
   918
richt@180
   919
           <p>
richt@180
   920
              The <dfn id="dom-networkservices-servicesavailable"><code>servicesAvailable</code></dfn> attribute MUST return the number of services available in the
richt@180
   921
              user's network that match the <a>valid service type</a> that was initially used to create the current <a href="#networkservices"><code>NetworkServices</code></a> object.
richt@180
   922
           </p>
richt@180
   923
richt@180
   924
           <p>
richt@191
   925
             When a previously unknown instance of a networked service matching one of the requested <a href="#dfn-valid-service-type">valid service types</a> becomes available on the user's current network, the <a>user agent</a> MUST increment the <a href="#dom-networkservices-servicesavailable"><code>servicesAvailable</code></a> attribute by <code>1</code> and then
richt@191
   926
             <a href="http://www.whatwg.org/specs/web-apps/current-work/complete/webappapis.html#queue-a-task" class="externalDFN">queue a task</a>
richt@191
   927
             to dispatch a newly created event with the name <code>serviceavailable</code> that uses the <code>Event</code> interface, which does
richt@191
   928
             not bubble, is not cancellable, and has no default action, at the current <a href="#networkservices"><code>NetworkServices</code></a>
richt@191
   929
             object.
richt@180
   930
           </p>
richt@180
   931
richt@180
   932
           <p>
richt@191
   933
             When a previously known instance of a networked service matching one of the requested <a href="#dfn-valid-service-type">valid service types</a> becomes unavailable on the user's current network, the <a>user agent</a> MUST decrement the <a href="#dom-networkservices-servicesavailable"><code>servicesAvailable</code></a> attribute by <code>1</code> and then
richt@191
   934
             <a href="http://www.whatwg.org/specs/web-apps/current-work/complete/webappapis.html#queue-a-task" class="externalDFN">queue a task</a>
richt@191
   935
              to dispatch a newly created event with the name <code>serviceunavailable</code> that uses the <code>Event</code> interface, which does
richt@191
   936
              not bubble, is not cancellable, and has no default action, at the current <a href="#networkservices"><code>NetworkServices</code></a>
richt@191
   937
              object.
richt@180
   938
           </p>
richt@180
   939
        </div>
richt@180
   940
richt@180
   941
      </section>
richt@180
   942
richt@180
   943
      <section>
richt@180
   944
      <h2>Methods</h2>
richt@180
   945
        <dl class="domintro">
richt@180
   946
        <dt>
richt@180
   947
          <code title="networkservices-getter">
richt@180
   948
            <a href="#networkservices">services</a>
richt@180
   949
          </code>
richt@180
   950
          [
richt@180
   951
          <var title="">index</var>
richt@180
   952
          ]
richt@180
   953
        </dt>
richt@180
   954
        <dd>
richt@180
   955
          <p>
richt@180
   956
            Returns the specified <a href="#networkservice"><code>NetworkService</code></a> object.
richt@180
   957
          </p>
richt@180
   958
        </dd>
richt@180
   959
        <dt>
richt@180
   960
          <code title="networkservices-getter">
richt@180
   961
            <a href="#networkservices">services</a>
richt@180
   962
          </code>
richt@180
   963
          .
richt@180
   964
          <code title="dom-networkservices-getservicebyid">
richt@180
   965
            <a href="#dom-networkservices-getservicebyid">getServiceById</a>
richt@180
   966
          </code>
richt@180
   967
          (
richt@180
   968
          <var title="">id</var>
richt@180
   969
          )
richt@180
   970
        </dt>
richt@180
   971
        <dd>
richt@180
   972
          <p>
richt@180
   973
            Returns the <a href="#networkservice"><code>NetworkService</code></a> object with the given identifier, or null if no
richt@180
   974
            service has that identifier.
richt@180
   975
          </p>
richt@180
   976
        </dd>
richt@180
   977
      </dl>
richt@180
   978
richt@180
   979
      <p>
richt@191
   980
        A <a href="#networkservices"><code>NetworkServices</code></a> object represents the current list of zero or more <a>current authorized services</a>, of which zero or more can be available at a time. Each item in <a>current authorized services</a> is represented by a <a href="#networkservice"><code>NetworkService</code></a> object. The list of <a>current authorized services</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
   981
      </p>
richt@180
   982
richt@180
   983
      <p class="note">
richt@180
   984
        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. If the <a>user agent</a> dynamically adds or removes network services for any reason, then the indices of the services in <a>current authorized services</a> will change dynamically. If the set of network services changes entirely, then all the previous services will be removed from <a>current authorized services</a> and replaced with new services.
richt@180
   985
      </p>
richt@180
   986
richt@180
   987
      <p>
richt@180
   988
        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 <a>current authorized services</a> represented by the respective object minus one, if any services are represented in <a>current authorized services</a>. If a <a href="#networkservices"><code>NetworkServices</code></a> object represents no <a>current authorized services</a>, it has no <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/infrastructure.html#supported-property-indices" class="externalDFN">supported property indices</a>.
richt@180
   989
      </p>
richt@180
   990
richt@180
   991
      <p>
richt@180
   992
        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>current authorized services</a>, the user agent MUST return the <a href="#networkservice"><code>NetworkService</code></a> object that represents the <var>index</var>th service in <a>current authorized services</a>.
richt@180
   993
      </p>
richt@180
   994
richt@180
   995
      <p>
richt@180
   996
        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 <a>current authorized services</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@180
   997
        When no services in <a>current authorized services</a> match the given argument, the method MUST return null.
richt@180
   998
      </p>
richt@180
   999
richt@180
  1000
      <p>
richt@180
  1001
         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
  1002
         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
  1003
         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
  1004
      </p>
richt@180
  1005
richt@180
  1006
      </section>
richt@180
  1007
richt@180
  1008
      <section>
richt@180
  1009
      <h2>Events</h2>
richt@180
  1010
richt@180
  1011
      <p>
richt@180
  1012
         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
  1013
       </p>
richt@180
  1014
richt@180
  1015
       <table border="1">
richt@180
  1016
        <thead>
richt@180
  1017
          <tr>
richt@180
  1018
            <th>
richt@180
  1019
              <span title="event handlers">Event handler</span>
richt@180
  1020
            </th>
richt@180
  1021
            <th>
richt@180
  1022
              <span>Event handler event type</span>
richt@180
  1023
            </th>
richt@180
  1024
          </tr>
richt@180
  1025
        </thead>
richt@180
  1026
        <tbody>
richt@180
  1027
          <tr>
richt@180
  1028
            <td>
richt@180
  1029
              <dfn id="dom-networkservices-onserviceavailable" title="dom-NetworkServices-onserviceavailable">
richt@180
  1030
                <code>onserviceavailable</code>
richt@180
  1031
              </dfn>
richt@180
  1032
            </td>
richt@180
  1033
            <td>
richt@180
  1034
              <code title="event-serviceavailable">serviceavailable</code>
richt@180
  1035
            </td>
richt@180
  1036
          </tr>
richt@180
  1037
          <tr>
richt@180
  1038
            <td>
richt@180
  1039
              <dfn id="dom-networkservices-onserviceunavailable" title="dom-NetworkServices-onserviceunavailable">
richt@180
  1040
                <code>onserviceunavailable</code>
richt@180
  1041
              </dfn>
richt@180
  1042
            </td>
richt@180
  1043
            <td>
richt@180
  1044
              <code title="event-serviceunavailable">serviceunavailable</code>
richt@180
  1045
            </td>
richt@180
  1046
          </tr>
richt@180
  1047
        </tbody>
richt@180
  1048
      </table>
richt@180
  1049
richt@180
  1050
      <p>
richt@180
  1051
         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
  1052
      </p>
richt@180
  1053
richt@180
  1054
      </section>
richt@180
  1055
richt@180
  1056
    </section>
richt@180
  1057
    <section>
richt@180
  1058
    <h2>Communicating with a networked service</h3>
richt@180
  1059
richt@180
  1060
<p>
richt@180
  1061
   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
  1062
</p>
richt@180
  1063
richt@180
  1064
<pre class="widl">
richt@180
  1065
[NoInterfaceObject]
richt@180
  1066
interface <dfn id="networkservice">NetworkService</dfn> {
richt@180
  1067
  readonly attribute DOMString        <a href="#dom-networkservice-id">id</a>;
richt@180
  1068
  readonly attribute DOMString        <a href="#dom-networkservice-name">name</a>;
richt@180
  1069
  readonly attribute DOMString        <a href="#dom-networkservice-type">type</a>;
richt@180
  1070
  readonly attribute DOMString        <a href="#dom-networkservice-url">url</a>;
richt@180
  1071
  readonly attribute DOMString        <a href="#dom-networkservice-config">config</a>;
richt@180
  1072
richt@191
  1073
  readonly attribute boolean          <a href="#dom-networkservice-online">online</a>;
richt@180
  1074
richt@180
  1075
  // event handler attributes
richt@191
  1076
           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
  1077
           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
  1078
richt@191
  1079
           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
  1080
};
richt@180
  1081
richt@180
  1082
<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
  1083
</pre>
richt@180
  1084
richt@180
  1085
<section>
richt@180
  1086
  <h2>Attributes</h2>
richt@180
  1087
richt@180
  1088
      <dl class="domintro">
richt@180
  1089
        <dt>
richt@180
  1090
          <var title="">service</var>
richt@180
  1091
           .
richt@180
  1092
          <code title="dom-networkservice-id">
richt@180
  1093
            <a href="#dom-networkservice-id">id</a>
richt@180
  1094
          </code>
richt@180
  1095
        </dt>
richt@180
  1096
        <dd>
richt@180
  1097
          <p>
richt@180
  1098
            A unique identifier for the given user-selected service instance.
richt@180
  1099
          </p>
richt@180
  1100
        </dd>
richt@180
  1101
        <dt>
richt@180
  1102
          <var title="">service</var>
richt@180
  1103
           .
richt@180
  1104
          <code title="dom-networkservice-name">
richt@180
  1105
            <a href="#dom-networkservice-name">name</a>
richt@180
  1106
          </code>
richt@180
  1107
        </dt>
richt@180
  1108
        <dd>
richt@180
  1109
          <p>
richt@180
  1110
            The name of the user-selected service.
richt@180
  1111
          </p>
richt@180
  1112
        </dd>
richt@180
  1113
        <dt>
richt@180
  1114
          <var title="">service</var>
richt@180
  1115
           .
richt@180
  1116
          <code title="dom-networkservice-type">
richt@180
  1117
            <a href="#dom-networkservice-type">type</a>
richt@180
  1118
          </code>
richt@180
  1119
        </dt>
richt@180
  1120
        <dd>
richt@180
  1121
          <p>
richt@180
  1122
            The <a>valid service type</a> token value of the user-selected service.
richt@180
  1123
          </p>
richt@180
  1124
        </dd>
richt@180
  1125
        <dt>
richt@180
  1126
          <var title="">service</var>
richt@180
  1127
           .
richt@180
  1128
          <code title="dom-networkservice-url">
richt@180
  1129
            <a href="#dom-networkservice-url">url</a>
richt@180
  1130
          </code>
richt@180
  1131
        </dt>
richt@180
  1132
        <dd>
richt@180
  1133
          <p>
richt@180
  1134
            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
  1135
          </p>
richt@180
  1136
        </dd>
richt@180
  1137
        <dt>
richt@180
  1138
          <var title="">service</var>
richt@180
  1139
           .
richt@180
  1140
          <code title="dom-networkservice-config">
richt@180
  1141
            <a href="#dom-networkservice-config">config</a>
richt@180
  1142
          </code>
richt@180
  1143
        </dt>
richt@180
  1144
        <dd>
richt@180
  1145
          <p>
richt@180
  1146
            The configuration information associated with the service depending on the requested service type.
richt@180
  1147
          </p>
richt@180
  1148
        </dd>
richt@180
  1149
      </dl>
richt@180
  1150
richt@180
  1151
          <p>
richt@180
  1152
            The <dfn id="dom-networkservice-id"><code>id</code></dfn> attribute is a unique identifier for the service. Two services provided at different times or on different objects MUST have the same <a href="#dom-networkservice-id"><code>id</code></a> value.
richt@180
  1153
         </p>
richt@180
  1154
richt@180
  1155
         <p>
richt@180
  1156
            The <dfn id="dom-networkservice-name"><code>name</code></dfn> attribute represents a human-readable title for the service.
richt@180
  1157
         </p>
richt@180
  1158
richt@180
  1159
         <p>
richt@180
  1160
             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
  1161
          </p>
richt@180
  1162
richt@180
  1163
         <p>
richt@180
  1164
            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
  1165
            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
  1166
         </p>
richt@180
  1167
richt@180
  1168
         <p>
richt@180
  1169
            The <dfn id="dom-networkservice-config"><code>config</code></dfn> attribute provides the raw configuration information extracted from the given network service.
richt@180
  1170
         </p>
richt@180
  1171
richt@180
  1172
      </section>
richt@180
  1173
richt@180
  1174
      <section>
richt@180
  1175
         <h3>States</h3>
richt@180
  1176
richt@180
  1177
      <dl class="domintro">
richt@180
  1178
        <dt>
richt@180
  1179
          <var title="">service</var>
richt@180
  1180
           .
richt@191
  1181
          <code title="dom-networkservice-online">
richt@191
  1182
            <a href="#dom-networkservice-online">online</a>
richt@180
  1183
          </code>
richt@180
  1184
        </dt>
richt@180
  1185
        <dd>
richt@180
  1186
          <p>
richt@191
  1187
            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
  1188
          </p>
richt@180
  1189
        </dd>
richt@180
  1190
      </dl>
richt@180
  1191
richt@191
  1192
      <p>
richt@191
  1193
        The <dfn id="dom-networkservice-config"><code>online</code></dfn> attribute indicates whether the service is reporting itself as being
richt@191
  1194
        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
  1195
      </p>
richt@180
  1196
richt@180
  1197
      </section>
richt@180
  1198
richt@180
  1199
      <section>
richt@180
  1200
         <h3>Events</h3>
richt@180
  1201
richt@180
  1202
      <p>
richt@180
  1203
         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
  1204
         <a href="#networkservice"><code>NetworkService</code></a> interface:
richt@180
  1205
       </p>
richt@180
  1206
richt@180
  1207
       <table border="1">
richt@180
  1208
        <thead>
richt@180
  1209
          <tr>
richt@180
  1210
            <th>
richt@180
  1211
              <span title="event handlers">Event handler</span>
richt@180
  1212
            </th>
richt@180
  1213
            <th>
richt@180
  1214
              <span>Event handler event type</span>
richt@180
  1215
            </th>
richt@180
  1216
          </tr>
richt@180
  1217
        </thead>
richt@180
  1218
        <tbody>
richt@180
  1219
          <tr>
richt@180
  1220
            <td>
richt@191
  1221
              <dfn id="dom-networkservice-onnotify" title="dom-NetworkService-onnotify">
richt@191
  1222
                <code>onnotify</code>
richt@180
  1223
              </dfn>
richt@180
  1224
            </td>
richt@180
  1225
            <td>
richt@191
  1226
              <code title="event-notify">notify</code>
richt@180
  1227
            </td>
richt@180
  1228
          </tr>
richt@180
  1229
          <tr>
richt@180
  1230
            <td>
richt@191
  1231
              <dfn id="dom-networkservice-onserviceonline" title="dom-NetworkService-onserviceonline">
richt@191
  1232
                <code>onserviceonline</code>
richt@180
  1233
              </dfn>
richt@180
  1234
            </td>
richt@180
  1235
            <td>
richt@191
  1236
              <code title="event-onserviceonline">serviceonline</code>
richt@191
  1237
            </td>
richt@191
  1238
          </tr>
richt@191
  1239
          <tr>
richt@191
  1240
            <td>
richt@191
  1241
              <dfn id="dom-networkservice-offserviceoffline" title="dom-NetworkService-onserviceoffline">
richt@191
  1242
                <code>onserviceoffline</code>
richt@191
  1243
              </dfn>
richt@191
  1244
            </td>
richt@191
  1245
            <td>
richt@191
  1246
              <code title="event-onserviceoffline">serviceoffline</code>
richt@180
  1247
            </td>
richt@180
  1248
          </tr>
richt@180
  1249
        </tbody>
richt@180
  1250
      </table>
richt@180
  1251
richt@180
  1252
      <p>
richt@191
  1253
         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
  1254
      </p>
richt@180
  1255
richt@180
  1256
      </section>
richt@180
  1257
   </section>
richt@180
  1258
richt@180
  1259
      <section>
richt@180
  1260
            <h2>Service Discovery</h2>
richt@180
  1261
richt@180
  1262
      <p>
richt@191
  1263
         A <a>user agent</a> conforming to this specification MAY implement <acronym title="Simple Service Discovery Protocol">SSDP</acronym> [[!UPNP]] and Zeroconf [[!DNS-SD]] + [[!MDNS]] service discovery mechanisms
richt@180
  1264
         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
  1265
      </p>
richt@180
  1266
      <p>
richt@180
  1267
         This section presents how the results of these two service discovery
richt@180
  1268
         mechanisms will be matched to requested service types and how their properties will be applied to any resulting <a href="#networkservice"><code>NetworkService</code></a> objects.
richt@180
  1269
      </p>
richt@180
  1270
richt@180
  1271
      <p>
richt@180
  1272
         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
  1273
         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
  1274
         invocation of this API from a Web page).
richt@180
  1275
      </p>
richt@180
  1276
richt@180
  1277
      <p>
richt@180
  1278
         The <dfn>list of available service records</dfn> is a single dynamic internal lookup table within user agents that is used to track the current services available in the network at any given time.
richt@180
  1279
         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@180
  1280
         services changes. Each record contained within this table contains the attributes: <code>id</code>, <code>name</code>, <code>type</code>, <code>url</code> and <code>config</code>.
richt@180
  1281
      </p>
richt@180
  1282
richt@180
  1283
            <section>
richt@180
  1284
         <h4>Zeroconf (<acronym title="Multicast DNS">mDNS</acronym> + <acronym title="Domain Name System">DNS</acronym>-<acronym title="Service Discovery">SD</acronym>)</h4>
richt@180
  1285
richt@180
  1286
         <p>
richt@180
  1287
            For each DNS response received from a user-agent-initiated Multicast DNS Browse for <acronym title="DNS Pointer Record">PTR</acronym> records with the name <code>_services._dns-sd._udp</code> on the resolved recommended automatic browsing
richt@180
  1288
   domain [[!MDNS]], the <a>user agent</a> MUST run the following steps:
richt@180
  1289
         </p>
richt@180
  1290
richt@180
  1291
         <ol class="rule">
richt@180
  1292
richt@180
  1293
            <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
  1294
richt@180
  1295
            <li>For each Object <var>service mDNS response</var> in <var>service mDNS responses</var>, run the following steps:
richt@180
  1296
               <ol>
richt@180
  1297
richt@180
  1298
                  <li>
richt@180
  1299
                     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>.
richt@180
  1300
                  </li>
richt@180
  1301
richt@180
  1302
                  <li>
richt@180
  1303
                     Set <var>network service record</var>'s <code>id</code> property to the value of the full PTR Service Instance Name [[!MDNS]].
richt@180
  1304
                  </li>
richt@180
  1305
richt@180
  1306
                  <li>
richt@180
  1307
                     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
  1308
                  </li>
richt@180
  1309
richt@180
  1310
                  <li>
richt@180
  1311
                     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
  1312
                  </li>
richt@180
  1313
richt@180
  1314
                  <li>
richt@180
  1315
                     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
  1316
                  </li>
richt@180
  1317
richt@180
  1318
                  <li>
richt@180
  1319
                     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
  1320
                  </li>
richt@180
  1321
richt@180
  1322
                  <li>
richt@180
  1323
                     For each Object <var>existing service record</var> in the current <a>list of available service records</a>, run the following sub-steps:
richt@180
  1324
                     <ol class="rule">
richt@180
  1325
richt@180
  1326
                       <li>
richt@180
  1327
                        If the <var>existing service record</var>'s <code>id</code> property matches the value of the <var>network service record</var>'s <code>id</code>, then set the
richt@180
  1328
                        value of <var>existing service record</var> in the current <a>list of available service records</a>  to the value of the
richt@180
  1329
                        <var>network service record</var> and skip the next step.
richt@180
  1330
                       </li>
richt@180
  1331
                     </ol>
richt@180
  1332
                  </li>
richt@180
  1333
richt@180
  1334
                  <li>
richt@180
  1335
                     Add <var>network service record</var> to the <a>list of available service records</a>.
richt@180
  1336
                  </li>
richt@180
  1337
richt@180
  1338
                  <li>
richt@180
  1339
                     For each non-garbage collected <a href="#networkservice"><code>NetworkService</code></a> object run the following steps:
richt@180
  1340
richt@180
  1341
                     <ol class="rule">
richt@180
  1342
                        <li>
richt@180
  1343
                           If the <a href="#networkservice"><code>NetworkService</code></a> object's <code>type</code> attribute does not equal the
richt@180
  1344
                           current <a>network service record</a>'s <code>type</code> property then continue at the next available active
richt@180
  1345
                           <a href="#networkservice"><code>NetworkService</code></a> object.
richt@180
  1346
                        </li>
richt@180
  1347
                        <li>
richt@191
  1348
                           Increment the <a href="#dom-networkservices-servicesavailable"><code>servicesAvailable</code></a> attribute of the <a href="#networkservices"><code>NetworkServices</code></a> object by <code>1</code>.
richt@191
  1349
                        </li>
richt@191
  1350
                        <li>
richt@191
  1351
                          <a href="http://www.whatwg.org/specs/web-apps/current-work/complete/webappapis.html#queue-a-task" class="externalDFN">Queue a task</a>
richt@191
  1352
                           to dispatch a newly created event with the name <code>serviceavailable</code> that uses the <code>Event</code> interface, which does not bubble, is not cancellable, and has no default action, at the current
richt@191
  1353
                            <a href="#networkservices"><code>NetworkServices</code></a> object.
richt@191
  1354
                        </li>
richt@191
  1355
                        <li>
richt@191
  1356
                          <a href="http://www.whatwg.org/specs/web-apps/current-work/complete/webappapis.html#queue-a-task" class="externalDFN">Queue a task</a>
richt@191
  1357
                           to dispatch a newly created event with the name <code>serviceonline</code> that uses the <code>Event</code> interface, which does not bubble, is not cancellable, and has no default action, at the current
richt@191
  1358
                           <a href="#networkservice"><code>NetworkService</code></a> object.
richt@180
  1359
                        </li>
richt@180
  1360
                     </ol>
richt@180
  1361
                  </li>
richt@180
  1362
            </ol>
richt@180
  1363
           </li>
richt@180
  1364
         </ol>
richt@180
  1365
richt@180
  1366
      </section>
richt@180
  1367
richt@180
  1368
      <section>
richt@180
  1369
         <h5>Universal Plug-and-Play (<acronym title="Universal Plug-and-Play">UPnP</acronym>)</h5>
richt@180
  1370
richt@180
  1371
         <p>
richt@180
  1372
            For each SSDP Presence Announcement [[!UPNP]] - a HTTP NOTIFY request - received from a user-agent-initiated SSDP Discovery Request [[!UPNP]], the <a>user agent</a> MUST run the following steps:
richt@180
  1373
         </p>
richt@180
  1374
richt@180
  1375
         <ol class="rule">
richt@180
  1376
            <li>
richt@180
  1377
               Let <var>ssdp device</var> be an Object with a property for each HTTP header received in the received SSDP Presence Announcement, with each key being the name of a HTTP header and its
richt@180
  1378
               value being that HTTP header's accompanying value.
richt@180
  1379
            </li>
richt@180
  1380
richt@180
  1381
            <li>
richt@180
  1382
               If <var>ssdp device</var> does not contain at least one <var>NTS</var>, <var>USN</var> and <var>Location</var> parameter, then the <a>user agent</a> MUST abort these steps.
richt@180
  1383
            </li>
richt@180
  1384
richt@180
  1385
            <li>
richt@180
  1386
               If the first occurrence of <var>NTS</var> has a value other than <code>ssdp:alive</code>, then continue to the step labeled <var>update service monitor</var> below.
richt@180
  1387
            </li>
richt@180
  1388
richt@180
  1389
            <li>
richt@180
  1390
               Let <var>root device descriptor file</var> contain the contents of the file located at the URL provided in the first occurrence of <var>Location</var> obtained according to the rules
richt@180
  1391
               defined in the section 'Retrieving a description using HTTP' [[!UPNP]].
richt@180
  1392
            </li>
richt@180
  1393
richt@180
  1394
            <li>
richt@180
  1395
               If <var>root device descriptor file</var> is empty, then the <a>user agent</a> MUST abort these steps.
richt@180
  1396
            </li>
richt@180
  1397
richt@180
  1398
            <li>
richt@180
  1399
               Let <var>advertised services</var> be a <a>list of all advertised services</a> obtained from the <var>root device descriptor file</var> containing all sub-nodes of the <code>serviceList</code> node as described in
richt@180
  1400
               the section 'Device Description' [[!UPNP]].
richt@180
  1401
            </li>
richt@180
  1402
richt@180
  1403
            <li>
richt@180
  1404
               For each Object <var>advertised service</var> in <var>advertised services</var> run the following steps:
richt@180
  1405
               <ol class="rule">
richt@180
  1406
richt@180
  1407
                  <li>
richt@180
  1408
                     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>eventsUrl</code>, <code>config</code>.
richt@180
  1409
                  </li>
richt@180
  1410
richt@180
  1411
                  <li>
richt@180
  1412
                     Set <var>network service record</var>'s <code>id</code> property to the string value of the first occurrence of <var>ssdp device</var>'s <var>USN</var> parameter.
richt@180
  1413
                  </li>
richt@180
  1414
richt@180
  1415
                  <li>
richt@180
  1416
                     Set <var>network service record</var>'s <code>name</code> property to the string value of the first occurrence of the <var>service</var>'s <code>serviceId</code> property.
richt@180
  1417
                  </li>
richt@180
  1418
richt@180
  1419
                  <li>
richt@180
  1420
                     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>service</var>'s <code>serviceType</code> property.
richt@180
  1421
                  </li>
richt@180
  1422
richt@180
  1423
                  <li>
richt@180
  1424
                     Set <var>network service record</var>'s <code>url</code> property to the string value of the first occurrence of the <var>service</var>'s <code>controlURL</code> property.
richt@180
  1425
                  </li>
richt@180
  1426
richt@180
  1427
                  <li>
richt@180
  1428
                     Set <var>network service record</var>'s <code>config</code> property to the string value of the first occurrence of the <var>device</var> property.
richt@180
  1429
                  </li>
richt@180
  1430
richt@180
  1431
                  <li>
richt@180
  1432
                     If <var>service</var>'s <code>eventSubURL</code> property is empty, then continue to the step labeled <em>register</em> below.
richt@180
  1433
                  </li>
richt@180
  1434
richt@180
  1435
                  <li>
richt@180
  1436
                     Set <var>network service record</var>'s <code>eventsUrl</code> property to the string value of the first occurrence of the <var>service</var>'s <code>eventSubURL</code> property.
richt@180
  1437
                  </li>
richt@180
  1438
richt@180
  1439
                  <li>
richt@180
  1440
                     <em>Register</em>: For each Object <var>existing service record</var> in the current <a>list of available service records</a>, run the following sub-steps:
richt@180
  1441
                     <ol class="rule">
richt@180
  1442
richt@180
  1443
                       <li>
richt@180
  1444
                        If the <var>existing service record</var>'s <var>id</var> property matches the value of the first occurrence of <var>USN</var> and the
richt@180
  1445
                        <var>existing service record</var>'s <code>type</code> property matches the value of <var>network service record</var>'s <code>type</code>, then set the
richt@180
  1446
                        value of <var>existing service record</var> in the current <a>list of available service records</a>  to the value of the
richt@180
  1447
                        <var>network service record</var> and skip the next step.
richt@180
  1448
                       </li>
richt@180
  1449
                     </ol>
richt@180
  1450
                  </li>
richt@180
  1451
richt@180
  1452
                  <li>
richt@180
  1453
                     Add <var>network service record</var> to the <a>list of available service records</a>.
richt@180
  1454
                  </li>
richt@180
  1455
richt@180
  1456
               </ol>
richt@180
  1457
            </li>
richt@180
  1458
            <li>
richt@180
  1459
               <em>Update Service Monitor</em>: For each non-garbage collected <a href="#networkservice"><code>NetworkService</code></a> object run the following steps:
richt@180
  1460
richt@180
  1461
               <ol class="rule">
richt@180
  1462
                  <li>
richt@180
  1463
                     If this <a href="#networkservice"><code>NetworkService</code></a> object's <code>type</code> attribute does not equal the
richt@180
  1464
                     current <a>network service record</a>'s <code>type</code> property then continue at the next available active
richt@180
  1465
                     <a href="#networkservice"><code>NetworkService</code></a> object.
richt@180
  1466
                  </li>
richt@180
  1467
                  <li>
richt@191
  1468
                     If the <var>announcement type</var> equals <code>ssdp:alive</code> then Increment the <a href="#dom-networkservices-servicesavailable"><code>servicesAvailable</code></a> attribute of the <a href="#networkservices"><code>NetworkServices</code></a>
richt@191
  1469
                     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@191
  1470
                      to dispatch a newly created event with the name <code>serviceonline</code> that uses the <code>Event</code> interface, which does not bubble, is not cancellable, and has no default action, at the current
richt@191
  1471
                      <a href="#networkservice"><code>NetworkService</code></a> object. Otherwise, decrement the <a href="#dom-networkservices-servicesavailable"><code>servicesAvailable</code></a> attribute of the <a href="#networkservices"><code>NetworkServices</code></a>
richt@191
  1472
                     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@191
  1473
                       to dispatch a newly created event with the name <code>serviceoffline</code> that uses the <code>Event</code> interface, which does not bubble, is not cancellable, and has no default action, at the current
richt@191
  1474
                       <a href="#networkservice"><code>NetworkService</code></a> object..
richt@180
  1475
                  </li>
richt@180
  1476
               </ol>
richt@180
  1477
            </li>
richt@180
  1478
         </ol>
richt@180
  1479
richt@180
  1480
         <p>
richt@180
  1481
            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.
richt@180
  1482
         </p>
richt@180
  1483
richt@180
  1484
         <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:</p>
richt@180
  1485
richt@180
  1486
         <ol class="rule">
richt@180
  1487
            <li>
richt@180
  1488
               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
  1489
            </li>
richt@180
  1490
richt@180
  1491
            <li>
richt@180
  1492
               Let <var>callback URL</var> be the value of creating a new <a>user-agent generated callback url</a>.
richt@180
  1493
            </li>
richt@180
  1494
richt@180
  1495
            <li>
richt@191
  1496
               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 an integer value ofÆ’
richt@180
  1497
               <code>86400</code> and a <em>CALLBACK</em> header
richt@180
  1498
               with a string value of <var>callback URL</var> towards the <var>network service record</var>'s <code>eventsUrl</code> property.
richt@180
  1499
            </li>
richt@180
  1500
richt@180
  1501
            <li>
richt@180
  1502
               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
  1503
            </li>
richt@180
  1504
richt@180
  1505
            <li>
richt@180
  1506
               On receiving a valid 200 OK response, run the following steps:
richt@180
  1507
richt@180
  1508
               <ol class="rule">
richt@180
  1509
                  <li>
richt@180
  1510
                     Let <var>callback ID</var> equal the string value of the first included <em>SID</em> header, if it exists.
richt@180
  1511
                  </li>
richt@180
  1512
                  <li>
richt@180
  1513
                     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, if it exists.
richt@180
  1514
                  </li>
richt@180
  1515
                  <li>
richt@180
  1516
                     Run the following steps aynchronously and continue to the step labeled <em>listen</em> below.
richt@180
  1517
                  </li>
richt@180
  1518
                  <li>
richt@180
  1519
                     <em>Refresh Subscription</em>: Run the following steps at a set interval (X) within the <a>user agent</a>:
richt@180
  1520
richt@180
  1521
                     <ol class="rule">
richt@180
  1522
                        <li>
richt@180
  1523
                           Let <var>current date</var> equal the current UTC date.
richt@180
  1524
                        </li>
richt@180
  1525
                        <li>
richt@180
  1526
                           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
  1527
                        </li>
richt@180
  1528
                        <li>
richt@180
  1529
                           Send a HTTP SUBSCRIBE request with a <em>SID</em> header with the string value of <var>callback ID</var> and a <em>TIMEOUT</em> header
richt@180
  1530
                           with an integer value of <code>86400</code> towards the <var>network service record</var>'s <code>eventsUrl</code> property.
richt@180
  1531
                        </li>
richt@180
  1532
                        <li>
richt@180
  1533
                           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
  1534
                           responses should cause the <a>user agent</a> to continue from the step labeled <em>refresh subscription</em> above.
richt@180
  1535
                        </li>
richt@180
  1536
                     </ol>
richt@180
  1537
richt@180
  1538
                  </li>
richt@180
  1539
richt@180
  1540
                  <li>
richt@180
  1541
                     <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
  1542
richt@180
  1543
                     <ol class="rule">
richt@180
  1544
                        <li>
richt@180
  1545
                           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
  1546
                        </li>
richt@180
  1547
                        <li>
richt@191
  1548
                          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
  1549
                           which does not bubble, is not cancellable, and has no default action.
richt@180
  1550
                        </li>
richt@180
  1551
                        <li>
richt@191
  1552
                           Let the <code>data</code> attribute of <var>notification event</var> have the DOMString value of <var>content clone</var>.
richt@180
  1553
                        </li>
richt@180
  1554
                        <li>
richt@180
  1555
                           <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
  1556
                            dispatch <var>notification event</var> at the current <a><code>NetworkService</code></a> object.
richt@180
  1557
                        </li>
richt@180
  1558
                     </ol>
richt@180
  1559
                  </li>
richt@180
  1560
richt@180
  1561
               </ol>
richt@180
  1562
richt@180
  1563
            </li>
richt@180
  1564
         </ol>
richt@180
  1565
richt@180
  1566
         </section>
richt@180
  1567
richt@180
  1568
         <section>
richt@180
  1569
            <h3>Network Topology Monitoring</h3>
richt@180
  1570
richt@180
  1571
                  <div>
richt@180
  1572
                     <p>
richt@180
  1573
                        When the <a>user agent</a> detects that the user has dropped from their connected network, then it MUST run the following steps:
richt@180
  1574
                     </p>
richt@180
  1575
richt@180
  1576
                     <ol class="rule">
richt@180
  1577
                        <li>
richt@180
  1578
                           Flush all entries from the <a>list of available service records</a>.
richt@180
  1579
                        </li>
richt@180
  1580
                        <li>
richt@180
  1581
                           For each <a href="#networkservice"><code>NetworkService</code></a> object currently active in the <a>user agent</a> perform the following steps:
richt@180
  1582
richt@180
  1583
                           <ol class="rule">
richt@180
  1584
                              <li>
richt@191
  1585
                                 Set the <a href="#dom-networkservice-online"><code>online</code></a> attribute to <code>false</code>.
richt@180
  1586
                              </li>
richt@180
  1587
                              <li>
richt@191
  1588
                                 <a href="http://www.whatwg.org/specs/web-apps/current-work/complete/webappapis.html#queue-a-task" class="externalDFN">Queue a task</a>
richt@191
  1589
                                                      to dispatch a newly created event with the name <code>serviceoffline</code> that uses the <code>Event</code> interface, which does not bubble, is not cancellable, and has no default action, at the current
richt@191
  1590
                                                      <a href="#networkservice"><code>NetworkService</code></a> object.
richt@180
  1591
                           </ol>
richt@180
  1592
                        </li>
richt@191
  1593
                        <li>
richt@191
  1594
                          For each <a href="#networkservices"><code>NetworkServices</code></a> object currently active in the <a>user agent</a> perform the following steps:
richt@191
  1595
richt@191
  1596
                          <ol class="rule">
richt@191
  1597
                            <li>
richt@191
  1598
                              Let <var>number of available services</var> equal the value of <a href="#networkservices"><code>NetworkServices</code></a>'s <a href="#dom-networkservices-servicesavailable"><code>servicesAvailable</code></a> attribute.
richt@191
  1599
                            </li>
richt@191
  1600
                            <li>
richt@191
  1601
                              Set the <a href="#networkservices"><code>NetworkServices</code></a>'s <a href="#dom-networkservices-servicesavailable"><code>servicesAvailable</code></a> attribute to zero (<code>0</code>).
richt@191
  1602
                            </li>
richt@191
  1603
                            <li>
richt@191
  1604
                              For each <var>available service</var> in <var>number of available services</var> the <a>user agent</a> MUST fire a new simple event with the name <code>serviceunavailable</code> that has no default action, does not bubble and is not cancellable, at the current <a href="#networkservices"><code>NetworkServices</code></a> object.
richt@191
  1605
                            </li>
richt@191
  1606
                          </ol>
richt@191
  1607
                        </li>
richt@191
  1608
richt@180
  1609
                     </ol>
richt@180
  1610
richt@180
  1611
                     <p>
richt@180
  1612
                        When the <a>user agent</a> detects that the user has connected to a new network, then it SHOULD run the following steps:
richt@180
  1613
                     </p>
richt@180
  1614
richt@180
  1615
                     <ol class="rule">
richt@180
  1616
                        <li>
richt@191
  1617
                           Re-issue an mDNS search and SSDP discovery search using all of the <a>valid service type</a> tokens initially provided to all active <a href="#networkservices"><code>NetworkServices</code></a> objects and handle all discovery responses according to the processing defined in <a href="#service-discovery">Section 7: Service Discovery</a>.
richt@180
  1618
                        </li>
richt@180
  1619
                     </ol>
richt@180
  1620
                  </div>
richt@180
  1621
         </section>
richt@180
  1622
      </section>
richt@180
  1623
richt@180
  1624
   <section>
richt@180
  1625
      <h3>Garbage collection</h3>
richt@180
  1626
richt@180
  1627
      <p>
richt@180
  1628
         A <a><code>NetworkService</code></a> object containing a <code>url</code> parameter currently in the <a>entry script origin's URL whitelist</a> MUST NOT be garbage collected.
richt@180
  1629
      </p>
richt@180
  1630
richt@180
  1631
      <p>
richt@180
  1632
         Only when the user navigates away from the current browsing context can <a><code>NetworkService</code></a> objects be garbage-collected and records in the <a>entry script origin's URL whitelist</a> be removed.
richt@180
  1633
      </p>
richt@180
  1634
richt@180
  1635
   </section>
richt@180
  1636
richt@180
  1637
richt@180
  1638
    <section>
richt@180
  1639
      <h3>Use Cases and Requirements</h3>
richt@180
  1640
richt@180
  1641
      <p>This section covers what the requirements are for this API, as well as illustrates some use cases.</p>
richt@180
  1642
richt@180
  1643
      <ul class="rule">
richt@180
  1644
         <li>
richt@180
  1645
            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
  1646
            <ul class="rule">
richt@180
  1647
               <li>
richt@180
  1648
                  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
  1649
                  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
  1650
                  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
  1651
                  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
  1652
                  the user-authorized Local-networked services.
richt@180
  1653
               </li>
richt@180
  1654
            </ul>
richt@180
  1655
         </li>
richt@180
  1656
richt@180
  1657
         <li>
richt@180
  1658
           Web pages should be able to communicate with Local-networked Services using the messaging channel supported by those Devices.
richt@180
  1659
           <ul class="rule">
richt@180
  1660
            <li>
richt@180
  1661
               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
  1662
               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
  1663
               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
  1664
            </li>
richt@180
  1665
           </ul>
richt@180
  1666
         </li>
richt@180
  1667
richt@180
  1668
         <li>
richt@180
  1669
           Web pages should be able to communicate with Local-networked Services using the messaging format supported by those Devices.
richt@180
  1670
           <ul class="rule">
richt@180
  1671
            <li>
richt@180
  1672
               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
  1673
               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
  1674
               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
  1675
               Server in the messaging format supported by that Device, which, in this example is a simple key/value pair text format.
richt@180
  1676
            </li>
richt@180
  1677
           </ul>
richt@180
  1678
         </li>
richt@180
  1679
richt@180
  1680
         <li>
richt@180
  1681
           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
  1682
           <ul class="rule">
richt@180
  1683
            <li>
richt@180
  1684
               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
  1685
               within the network, should not be accessible to the current Web page.
richt@180
  1686
            </li>
richt@180
  1687
           </ul>
richt@180
  1688
         </li>
richt@180
  1689
richt@180
  1690
         <li>
richt@180
  1691
           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
  1692
           <ul class="rule">
richt@180
  1693
            <li>
richt@180
  1694
               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
  1695
               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
  1696
               actions on to one or more of the authorized Local-networked Services.
richt@180
  1697
            </li>
richt@180
  1698
           </ul>
richt@180
  1699
         </li>
richt@180
  1700
richt@180
  1701
         <li>
richt@180
  1702
           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
  1703
           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
  1704
           these APIs occur silently without user intervention.
richt@180
  1705
         </li>
richt@180
  1706
      </ul>
richt@180
  1707
    </section>
richt@180
  1708
richt@180
  1709
          <section class="informative appendix">
richt@180
  1710
             <h3>Examples</h3>
richt@180
  1711
richt@180
  1712
           <div class="example">
richt@180
  1713
            <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
  1714
            <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
  1715
            <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
  1716
            <hr />
richt@180
  1717
            <pre class="brush:js">&lt;input type="button" value="Start" onclick="start()" id="startBtn"/&gt;
richt@180
  1718
&lt;div id="debugconsole">&lt;/div>
richt@180
  1719
richt@180
  1720
&lt;script>
richt@180
  1721
 var startBtn = document.getElementById('startBtn'),
richt@180
  1722
     debug = document.getElementById('debugconsole');
richt@180
  1723
richt@180
  1724
 function start() {
richt@180
  1725
   if(navigator.getNetworkServices) {
richt@180
  1726
      navigator.getNetworkServices('zeroconf:_xbmc-jsonrpc._tcp', gotXBMCService, error);
richt@180
  1727
      startBtn.disabled = true;
richt@180
  1728
   } else {
richt@191
  1729
      debug.innerHTML += "&lt;br&gt;Service Discovery not supported!";
richt@180
  1730
   }
richt@180
  1731
 }
richt@180
  1732
richt@180
  1733
 function gotXBMCService(services) {
richt@180
  1734
richt@180
  1735
// Listen for service disconnect messages
richt@180
  1736
richt@191
  1737
   services[0].addEventListener('serviceoffline', function ( e ) {
richt@180
  1738
       debug.innerHTML += "&lt;br>" + services[0].name + " disconnected.";
richt@180
  1739
       startBtn.disabled = false;
richt@180
  1740
   }, false);
richt@180
  1741
richt@180
  1742
// Send a service message to get albums list (and process the service response)
richt@180
  1743
richt@180
  1744
   var svcXhr = new XMLHttpRequest();
richt@180
  1745
   svcXhr.open("POST", services[0].url + "/getAlbums"); // services[0].url and its subresources have been
richt@180
  1746
                                                        // whitelisted for cross-site XHR use in this
richt@180
  1747
                                                        // current browsing context.
richt@180
  1748
richt@180
  1749
   svcXhr.setRequestHeader('Content-Type', 'application/json-rpc');
richt@180
  1750
richt@180
  1751
   svcXhr.addEventListener('readystatechange', function ( response ) {
richt@180
  1752
     if( response.readyState != 4 || response.status != 200 )
richt@180
  1753
        return;
richt@180
  1754
     debug.innerHTML += "&lt;br>" + services[0].name + " response received: ";
richt@180
  1755
     debug.textContent += JSON.parse(response.responseText);
richt@180
  1756
   }, false);
richt@180
  1757
richt@180
  1758
   var svcMsg = [
richt@180
  1759
     { "jsonrpc": "2.0", "method": "AudioLibrary.GetAlbums", "params": { "genreid": -1,
richt@180
  1760
         "artistid": -1, "start": -1, "end": -1 }, "id": "1" }
richt@180
  1761
   ];
richt@180
  1762
richt@180
  1763
   svcXhr.send(JSON.stringify(svcMsg));
richt@180
  1764
   debug.innerHTML += "&lt;br>" + services[0].name + " request sent: ";
richt@180
  1765
   debug.textContent += JSON.stringify(svcMsg);
richt@180
  1766
richt@180
  1767
 }
richt@180
  1768
richt@180
  1769
 function error( err ) {
richt@180
  1770
   debug.innerHTML += "&lt;br>An error occurred obtaining a local network service.";
richt@180
  1771
   startBtn.disabled = false;
richt@180
  1772
 }
richt@180
  1773
&lt;/script></pre>
richt@180
  1774
           </div>
richt@180
  1775
richt@180
  1776
           <div class="example">
richt@180
  1777
            <p>
richt@180
  1778
             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
  1779
             based on the service type requested. The user may also select multiple network services matching the selected service type.
richt@180
  1780
             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
  1781
             (<var>urn:schemas-upnp-org:service:RenderingControl:1</var>).
richt@180
  1782
             <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
  1783
            </p>
richt@180
  1784
            <hr />
richt@180
  1785
            <pre class="brush:js">&lt;select name="make" id="make"&gt;
richt@180
  1786
  &lt;option selected="selected" disabled="disabled"&gt;Select make&lt;/option&gt;
richt@180
  1787
  &lt;option&gt;Sony&lt;/option&gt;
richt@180
  1788
  &lt;option&gt;Philips&lt;/option&gt;
richt@180
  1789
  &lt;option&gt;Alba&lt;/option&gt;
richt@180
  1790
&lt;/select&gt;
richt@180
  1791
&lt;select name="model" id="model"&gt;&lt;/select&gt;
richt@180
  1792
&lt;div id="debugconsole"&gt;&lt;/div&gt;
richt@180
  1793
richt@180
  1794
&lt;script&gt;
richt@180
  1795
  var debug = document.getElementById('debugconsole');
richt@180
  1796
richt@180
  1797
  var models = {
richt@180
  1798
    "Sony": [
richt@180
  1799
      {"name": "Bravia TV S1000", "type": "upnp", "service": "urn:schemas-upnp-org:service:RenderingControl:1" },
richt@180
  1800
      {"name": "Bravia TV S2000", "type": "zeroconf", "service": "_mediarenderer._http._tcp" },
richt@180
  1801
      {"name": "HiFi WD10", "type": "upnp", "service": "urn:schemas-upnp-org:service:RenderingControl:1" }
richt@180
  1802
    ],
richt@180
  1803
    "Philips": [ /* ... */ ],
richt@180
  1804
    "Alba": [ /* ... */ ]
richt@180
  1805
  };
richt@180
  1806
richt@180
  1807
  var makeEl = document.getElementById("make"),
richt@180
  1808
      modelEl = document.getElementById("model");
richt@180
  1809
richt@180
  1810
  makeEl.addEventListener('change', function() {
richt@180
  1811
    modelEl.innerHTML = ""; // reset
richt@180
  1812
    var defaultOption = document.createElement("option");
richt@180
  1813
    defaultOption.textContent = "Select model";
richt@180
  1814
    defaultOption.setAttribute("disabled", "disabled");
richt@180
  1815
    defaultOption.setAttribute("selected", "selected");
richt@180
  1816
    modelEl.appendChild(defaultOption);
richt@180
  1817
    for(var i = 0, l = models[makeEl.value].length; i < l; i++) {
richt@180
  1818
      var option = document.createElement("option");
richt@180
  1819
      option.textContent = models[makeEl.value][i]["name"];
richt@180
  1820
      option.setAttribute("value", models[makeEl.value][i]["type"] + ":" + models[makeEl.value][i]["service"]);
richt@180
  1821
      modelEl.appendChild(option);
richt@180
  1822
    }
richt@180
  1823
  }, false);
richt@180
  1824
richt@180
  1825
  modelEl.addEventListener('change', function() {
richt@180
  1826
    if(navigator.getNetworkServices &&
richt@180
  1827
         modelEl.value == "upnp:urn:schemas-upnp-org:service:RenderingControl:1") {
richt@180
  1828
      navigator.getNetworkServices(modelEl.value, successCallback, errorCallback);
richt@180
  1829
    } else if (modelEl.value == "zeroconf:_mediarenderer._http._tcp") {
richt@180
  1830
      debug.innerHTML += "&lt;br&gt;Service type is not implemented by this application.";
richt@180
  1831
    } else {
richt@180
  1832
      debug.innerHTML += "&lt;br&gt;Service Discovery is not supported!";
richt@180
  1833
    }
richt@180
  1834
  }, false);
richt@180
  1835
&lt;/script&gt;
richt@180
  1836
richt@180
  1837
&lt;script&gt;
richt@180
  1838
  function successCallback( services ) {
richt@180
  1839
richt@191
  1840
  // Listen for service push notification messages
richt@180
  1841
richt@191
  1842
    services[0].addEventListener('notify', function ( msg ) {
richt@180
  1843
         debug.innerHTML += "&lt;br>" + services[0].name + " event received: ";
richt@180
  1844
         debug.textContent += msg.data;
richt@180
  1845
    }, false);
richt@180
  1846
richt@180
  1847
 // Send a control signal to mute the service audio
richt@180
  1848
richt@180
  1849
    var svcXhr = new XMLHttpRequest();
richt@180
  1850
    svcXhr.open("POST", services[0].url); // services[0].url and its
richt@180
  1851
                                          // subresources have been whitelisted for
richt@180
  1852
                                          // cross-site XHR use in this current
richt@180
  1853
                                          // browsing context.
richt@180
  1854
richt@180
  1855
    svcXhr.setRequestHeader('SOAPAction', 'urn:schemas-upnp-org:service:RenderingControl:1#SetMute');
richt@180
  1856
    svcXhr.setRequestHeader('Content-Type', 'text/xml; charset="utf-8";');
richt@180
  1857
richt@180
  1858
    svcXhr.onreadystatechange = function ( response ) {
richt@180
  1859
      if( response.readyState != 4 || response.status != 200 )
richt@180
  1860
        return;
richt@180
  1861
      debug.innerHTML += "&lt;br&gt;" + services[0].name + " response received: ";
richt@180
  1862
      debug.textContent += response.responseXML;
richt@180
  1863
    }
richt@180
  1864
richt@180
  1865
    // Service messaging to mute the provided service
richt@180
  1866
    var svcMsg = '&lt;?xml version="1.0" encoding="utf-8"?&gt;' +
richt@180
  1867
                 '&lt;s:Envelope s:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/" ' +
richt@180
  1868
                   'xmlns:s="http://schemas.xmlsoap.org/soap/envelope/"&gt;' +
richt@180
  1869
                   '&lt;s:Body&gt;' +
richt@180
  1870
                     '&lt;u:SetMute xmlns:u="urn:schemas-upnp-org:service:RenderingControl:1"&gt;' +
richt@180
  1871
                       '&lt;InstanceID&gt;0&lt;/InstanceID&gt;' +
richt@180
  1872
                       '&lt;Channel&gt;Master&lt;/Channel&gt;' +
richt@180
  1873
                       '&lt;DesiredMute&gt;true&lt;/DesiredMute&gt;' +
richt@180
  1874
                     '&lt;/u:SetMute&gt;' +
richt@180
  1875
                   '&lt;/s:Body&gt;' +
richt@180
  1876
                 '&lt;/s:Envelope&gt;';
richt@180
  1877
richt@180
  1878
    svcXhr.send(svcMsg);
richt@180
  1879
    debug.innerHTML += "&lt;br&gt;" + services[0].name + " request sent: ";
richt@180
  1880
    debug.textContent += svcMsg;
richt@180
  1881
  }
richt@180
  1882
richt@180
  1883
  function errorCallback( error ) {
richt@180
  1884
    debug.innerHTML += "&lt;br&gt;An error occurred: " + error.code;
richt@180
  1885
  }
richt@180
  1886
&lt;/script&gt;</pre>
richt@180
  1887
          </div>
richt@180
  1888
richt@180
  1889
       </section>
richt@180
  1890
richt@180
  1891
    <section>
richt@180
  1892
      <h3>Acknowledgements</h3>
richt@180
  1893
richt@180
  1894
      <p>Thanks are expressed by the editor to the following individuals for their feedback on this specification to date (in alphabetical order):
richt@180
  1895
      <br /><br />
richt@191
  1896
      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
  1897
richt@180
  1898
      <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
  1899
      <br /></br />
richt@180
  1900
      CableLabs, Opera Software ASA, W3C Device APIs Working Group, W3C Web and TV Interest Group, ...</p>
richt@180
  1901
    </section>
richt@180
  1902
richt@180
  1903
    <script class='remove'>
richt@180
  1904
    if(SyntaxHighlighter) {
richt@180
  1905
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richt@180
  1906
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richt@180
  1907
      SyntaxHighlighter.all()
richt@180
  1908
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richt@180
  1909
    </script>
richt@180
  1910
richt@180
  1911
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richt@180
  1912
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