Firefox 24 for developers

  • Revision slug: Mozilla/Firefox/Releases/24
  • Revision title: Firefox 24 for developers
  • Revision id: 484655
  • Created:
  • Creator: frankyan
  • Is current revision? No
  • Comment

Revision Content

This page is not complete
It hasn't been fully updated since Firefox 24 was released.

Want to help document Firefox 24? See the list of bugs that need to be written about and pitch in!

Changes for Web developers

CSS

  • The two values -moz-zoom-in and -moz-zoom-out of the {{cssxref("cursor")}} property have been unprefixed to zoom-in and zoom-out ({{bug("772153")}}).

HTML

  • The {{HTMLElement("track")}} element has been implemented behind the media.webvtt.enabled property ({{bug(833385)}}).

JavaScript

  • Arrow functions are no longer automatically in strict mode unless explicitly requested with "use strict" ({{bug(852762)}}).
  • The String.prototype.repeat JS method has been implemented ({{bug(815431)}}).

DOM

  • Support for the {{domxref("Range.Range", "Range()")}} constructor has been added ({{bug(868999)}}).
  • Support for the {{domxref("Text.Text", "Text()")}} constructor has been added ({{bug(869000)}}).
  • Support for the {{domxref("Comment.Comment", "Comment()")}} constructor has been added ({{bug(869006)}}).
  • Support for the {{domxref("DocumentFragment.DocumentFragment", "DocumentFragment()")}} constructor has been added ({{bug(869002)}}).
  • The {{domxref("FocusEvent")}} interface has been implemented ({{bug(855741)}}).
  • Support for the {{domxref("ChildNode.remove()")}} method has been added ({{bug(856629)}}).
  • The interfaces related to the {{HTMLElement("track")}} element, {{domxref("HTMLTrackElement")}}, {{domxref("TextTrack")}}, {{domxref("TextTrackCue")}}, {{domxref("TextTrackList")}}, and {{domxref("TextTrackCueList")}} have been implemented behind the media.webvtt.enabled property, defaulting to false ({{bug(833385)}}).
  • The {{domxref("Gamepad")}} interface, and {{domxref("Navigator.getGamepads")}} have been implemented behind the dom.gamepad.enabled property, defaulting to false ({{bug(690935)}}).
  • On desktop Firefox only, HTMLCanvasElement.getContext() can now take the webgl value, in addition to experimental-webgl ({{bug(870232)}}).
  • The non-standard method mozLoadFrom() of {{domxref("HTMLMediaElement")}} has been removed ({{bug(877135)}}).

Developer Tools

  • The Network inspector now lets you filter by content type (CSS/image/font etc.) and see the relevant size and load times.
  • The Devtools options panel to the left lets you disable/enable Javascript temporarily.
  • Extension developers may use the new Browser Console for Chrome-level scripts (Replaces Error Console).

MathML

  • The dir attribute for controlling directionality of formulas on e.g. {{MathMLElement("math")}} or {{MathMLElement("mrow")}} elements is now equivalent to using the {{cssxref("direction")}} CSS property.
  • The equal sign ("=") is now stretchable.
  • The "updiagonalarrow" value for the notation attribute on {{MathMLElement("menclose")}} elements has been added.

See also

Older versions

{{Firefox_for_developers('23')}}

Revision Source

<div class="overheadIndicator draft draftHeader">
 <strong>This page is not complete</strong>
 <div>
  It hasn't been fully updated since Firefox 24 was released.</div>
</div>
<p>Want to help document Firefox 24? See the <a class="external" href="http://beta.elchi3.de/doctracker/#list=fx&amp;version=24.0">list of bugs that need to be written about</a> and pitch in!</p>
<h2 id="Changes_for_Web_developers">Changes for Web developers</h2>
<h3 id="CSS">CSS</h3>
<ul>
 <li>The two values <code>-moz-zoom-in</code> and <code>-moz-zoom-out</code> of the {{cssxref("cursor")}} property have been unprefixed to <code>zoom-in</code> and <code>zoom-out</code> ({{bug("772153")}}).</li>
</ul>
<h3 id="HTML">HTML</h3>
<ul>
 <li>The {{HTMLElement("track")}} element has been implemented behind the <code>media.webvtt.enabled</code> property ({{bug(833385)}}).</li>
</ul>
<h3 id="JavaScript">JavaScript</h3>
<ul>
 <li><a href="/en-US/docs/Web/JavaScript/Reference/arrow_functions" title="/en-US/docs/Web/JavaScript/Reference/arrow_functions">Arrow functions</a> are no longer automatically in strict mode unless explicitly requested with <code>"use strict"</code> ({{bug(852762)}}).</li>
 <li>The <a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/repeat" title="/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/repeat"><code>String.prototype.repeat</code></a> JS method has been implemented ({{bug(815431)}}).</li>
</ul>
<h3 id="DOM">DOM</h3>
<ul>
 <li>Support for the {{domxref("Range.Range", "Range()")}} constructor has been added ({{bug(868999)}}).</li>
 <li>Support for the {{domxref("Text.Text", "Text()")}} constructor has been added ({{bug(869000)}}).</li>
 <li>Support for the {{domxref("Comment.Comment", "Comment()")}} constructor has been added ({{bug(869006)}}).</li>
 <li>Support for the {{domxref("DocumentFragment.DocumentFragment", "DocumentFragment()")}} constructor has been added ({{bug(869002)}}).</li>
 <li>The {{domxref("FocusEvent")}} interface has been implemented ({{bug(855741)}}).</li>
 <li>Support for the {{domxref("ChildNode.remove()")}} method has been added ({{bug(856629)}}).</li>
 <li>The interfaces related to the {{HTMLElement("track")}} element, {{domxref("HTMLTrackElement")}}, {{domxref("TextTrack")}}, {{domxref("TextTrackCue")}}, {{domxref("TextTrackList")}}, and {{domxref("TextTrackCueList")}} have been implemented behind the <code>media.webvtt.enabled</code> property, defaulting to <code>false</code> ({{bug(833385)}}).</li>
 <li>The {{domxref("Gamepad")}} interface, and {{domxref("Navigator.getGamepads")}} have been implemented behind the <code>dom.gamepad.enabled</code> property, defaulting to <code>false</code> ({{bug(690935)}}).</li>
 <li>On desktop Firefox only, <code>HTMLCanvasElement.getContext()</code> can now take the <code>webgl</code> value, in addition to <code>experimental-webgl</code> ({{bug(870232)}}).</li>
 <li>The non-standard method <code>mozLoadFrom()</code> of {{domxref("HTMLMediaElement")}} has been removed ({{bug(877135)}}).</li>
</ul>
<h3 id="Developer_Tools">Developer Tools</h3>
<ul>
 <li>The Network inspector now lets you filter by content type (CSS/image/font etc.) and see the relevant size and load times.</li>
 <li>The Devtools options panel to the left lets you disable/enable Javascript temporarily.</li>
 <li>Extension developers may use the new <a href="http://www.robodesign.ro/mihai/blog/the-browser-console-is-replacing-the-error-console" title="http://www.robodesign.ro/mihai/blog/the-browser-console-is-replacing-the-error-console">Browser Console</a> for Chrome-level scripts (Replaces Error Console).</li>
</ul>
<h3 id="MathML">MathML</h3>
<ul>
 <li>The <code>dir</code> attribute for controlling directionality of formulas on e.g. {{MathMLElement("math")}} or {{MathMLElement("mrow")}} elements is now equivalent to using the {{cssxref("direction")}} CSS property.</li>
 <li>The equal sign ("=") is now <a href="/en-US/docs/Web/MathML/Element/mo#attr-stretchy">stretchable</a>.</li>
 <li>The "<code>updiagonalarrow</code>" value for the <code>notation</code> attribute on {{MathMLElement("menclose")}} elements has been added.</li>
</ul>
<h2 id="See_also">See also</h2>
<ul>
 <li><a href="http://www.mozilla.org/en-US/firefox/24.0a2/auroranotes/">Firefox 24 Aurora Notes</a></li>
 <li><a href="/en-US/docs/Site_Compatibility_for_Firefox_24">Site Compatibility for Firefox 24</a></li>
</ul>
<h3 id="Older_versions">Older versions</h3>
<p>{{Firefox_for_developers('23')}}</p>
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