Site Compatibility for Firefox 25

  • Revision slug: Mozilla/Firefox/Releases/25/Site_Compatibility
  • Revision title: Site Compatibility for Firefox 25
  • Revision id: 440527
  • Created:
  • Creator: Yoshino
  • Is current revision? No
  • Comment

Revision Content

{{ draft() }}

Firefox 25 Aurora (pre-Beta) will be released on . While it has been developed to maintain compatibility as much as possible, the new version includes some changes affecting backward compatibility aimed at improving interoperability with the other browsers or following the latest Web standards. Here's the list of such changes — Hope this helps whenever you test your sites or applications.

This article only explains the changes that may affect backward compatibility for Websites. For the other new features and changes, please read the following documents:

This list may be updated until the release of the final version on , so please check back later.

DOM

ImageDocument has been removed

The non-standard {{ domxref("ImageDocument") }} interface is no longer available from Web content.

Events in workers have been prefixed with Worker

In order to make normal DOM events work in workers, the current events in workers including {{ domxref("Event") }}, {{ domxref("MessageEvent") }}, {{ domxref("ErrorEvent") }} and {{ domxref("ProgressEvent") }} have been renamed to {{ domxref("WorkerEvent") }}, {{ domxref("WorkerMessageEvent") }}, {{ domxref("WorkerErrorEvent") }} and {{ domxref("WorkerProgressEvent") }}.

JavaScript

Proxy has been changed to be a function

Previously, Proxy was an object. Now typeof Proxy returns function and the interface is callable without the new operator. You may have to care about this if you are using the typeof operator for a feature detection.

yield without a value has been deprecated

The yield operator now cannot be used without an operand (its value). This change has been made to comply with the ECMAScript 6 spec, and you'll see a warning in the Web Console if no value is specified in your code.

Revision Source

<p>{{ draft() }}</p>
<p>Firefox&nbsp;25 <a href="http://www.mozilla.org/en-US/firefox/aurora/">Aurora</a> (pre-Beta) will be released on <time datetime="2013-08-09">August&nbsp;9, 2013</time>. While it has been developed to maintain compatibility as much as possible, the new version includes some changes affecting backward compatibility aimed at improving interoperability with the other browsers or following the latest Web standards. Here's the list of such changes — Hope this helps whenever you test your sites or applications.</p>
<p><strong>This article only explains the changes that may affect backward compatibility for Websites</strong>. For the other new features and changes, please read the following documents:</p>
<ul>
  <li><a href="/en-US/docs/Mozilla/Firefox/Releases/25">Firefox&nbsp;25 for developers</a></li>
</ul>
<p>This list may be updated until the release of the final version on <time datetime="2013-10-29">October&nbsp;29, 2013</time>, so please check back later.</p>
<section id="sect1">
  <h2 id="DOM">DOM</h2>
  <section id="sect2">
    <h3 id="ImageDocument_has_been_removed"><code>ImageDocument</code> has been removed</h3>
    <ul>
      <li><a href="https://bugzilla.mozilla.org/show_bug.cgi?id=885177">Bug&nbsp;885177 – Make window.ImageDocument ChromeOnly</a></li>
    </ul>
    <p>The non-standard {{ domxref("ImageDocument") }} interface is no longer available from Web content.</p>
  </section>
  <section id="sect3">
    <h3 id="Events_in_workers_have_been_prefixed_with_Worker">Events in workers have been prefixed with <code>Worker</code></h3>
    <ul>
      <li><a href="https://bugzilla.mozilla.org/show_bug.cgi?id=887236">Bug&nbsp;887236 – prefix the current events in workers with "Worker"</a></li>
    </ul>
    <p>In order to make normal DOM events work in <a href="/en-US/docs/Web/Guide/Performance/Using_web_workers">workers</a>, the current events in workers including {{ domxref("Event") }}, {{ domxref("MessageEvent") }}, {{ domxref("ErrorEvent") }} and {{ domxref("ProgressEvent") }} have been renamed to {{ domxref("WorkerEvent") }}, {{ domxref("WorkerMessageEvent") }}, {{ domxref("WorkerErrorEvent") }} and {{ domxref("WorkerProgressEvent") }}.</p>
  </section>
</section>
<section id="sect4">
  <h2 id="JavaScript">JavaScript</h2>
  <section id="sect5">
    <h3 id="Proxy_has_been_changed_to_be_a_function"><code>Proxy</code> has been changed to be a function</h3>
    <ul>
      <li><a href="https://bugzilla.mozilla.org/show_bug.cgi?id=788172">Bug&nbsp;788172 – Proxy is not a function (typeof Proxy should be 'function')</a></li>
    </ul>
    <p>Previously, <a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects/Proxy"><code>Proxy</code></a> was an object. Now <code>typeof Proxy</code> returns <code>function</code> and the interface is callable without the <a href="/en-US/docs/Web/JavaScript/Reference/Operators/new"><code>new</code></a> operator. You may have to care about this if you are using the <a href="/en-US/docs/Web/JavaScript/Reference/Operators/typeof"><code>typeof</code></a> operator for a feature detection.</p>
  </section>
  <section id="sect6">
    <h3 id="yield_without_a_value_has_been_deprecated"><code>yield</code> without a value has been deprecated</h3>
    <ul>
      <li><a href="https://bugzilla.mozilla.org/show_bug.cgi?id=885463">Bug&nbsp;885463 – Warn about 'yield' without operand</a></li>
    </ul>
    <p>The <a href="/en-US/docs/Web/JavaScript/Reference/Operators/yield"><code>yield</code></a> operator now cannot be used without an operand (its value). This change has been made to comply with the <a href="/en-US/docs/JavaScript/ECMAScript_6_support_in_Mozilla">ECMAScript&nbsp;6</a> spec, and you'll see a warning in the <a href="/en-US/docs/Tools/Web_Console">Web Console</a> if no value is specified in your code.</p>
  </section>
</section>
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