Firefox 23 for developers

  • Revision slug: Mozilla/Firefox/Releases/23
  • Revision title: Firefox 23 for developers
  • Revision id: 459965
  • Created:
  • Creator: teoli
  • Is current revision? No
  • Comment

Revision Content

Want to help document Firefox 23? See the list of bugs that need to be written about and pitch in!

Changes for Web developers

Security

  • Mixed content blocking. Firefox will no longer load non-secure (http) resources on secure (https) pages ({{bug(834836)}}).
  • The standard syntax of CSP 1.0 policies are now implemented and enforced by default.

Developer Tools

  • A Network Panel has been added to the developer tools. This is more detailed view than the "Net" view option in the Web Console.
  • Web Console has been renamed "Console", and includes the option to filter security errors/warnings.
  • The new Toolbox Options lets you disable features, change light/dark theme, or enable Chrome/Remote debugging.

HTML

  • The {{HTMLElement("blink")}} element support is now completely dropped. The <blink> tag now implements the {{domxref("HTMLUnknownElement")}} interface ({{bug(857820)}}).
  • The range state of the {{HTMLElement("input")}} element (<input type="range">) has been switched on by default ({{bug(841950)}}).

JavaScript

  • The Object.defineProperty method can now be used to redefine the length property of an Array object.
  • The option to disable JavaScript, including the options to allow moving windows/replace context menu, have been removed. You may still disable JavaScript by double clicking the "javascript.enabled" option in about:config.

DOM

  • D3E KeyboardEvent.key is now supported, but only for non-printable keys ({{bug(842927)}}).
  • The title attribute of {{domxref("DOMImplementation.createHTMLDocument")}} is now optional as per updated DOM specification.
  • The ability to add a sidebar panel (window.sidebar.addPanel) has been dropped ({{bug(691647)}}).
  • The unprefixed {{domxref("window.requestAnimationFrame")}} and {{domxref("window.cancelAnimationFrame")}} methods has been added. ({{bug(704063)}})
  • The text argument for {{domxref("window.alert")}} and {{domxref("window.confirm")}} is now optional ({{bug(861605)}}).
  • The {{domxref("HTMLMediaElement.initialTime")}} property, removed from the spec, is no more supported ({{bug(742537)}}).
  • The {{domxref("AnimationEvent.AnimationEvent", "AnimationEvent()")}} constructor has been added ({{bug(848293)}}).
  • The {{domxref("AnimationEvent.pseudoElement")}} property has been implemented ({{bug(848293)}}).
  • The {{domxref("TransitionEvent.TransitionEvent", "TransitionEvent()")}} constructor has been added ({{bug(848291)}}).
  • The {{domxref("TransitionEvent.pseudoElement")}} property has been implemented ({{bug(848291)}}).
  • The non-standard {{domxref("TransitionEvent.initTransitionEvent()")}} and {{domxref("AnimationEvent.initAnimationEvent()")}} have been removed ({{bug(868751)}}).

CSS

  • The blink effect for text-decoration: blink; has no more effect, but is still a valid value ({{bug(857820)}}).

MathML

  • Negative widths for the {{MathMLElement("mspace")}} element has been implemented ({{bug(717546)}}).
  • The {{MathMLElement("semantics")}} element now determines the visible child as described in the MathML3 specification.

Changes for addon and Mozilla developers

Firefox developer tools

Addons that overlay chrome://browser/content/debugger.xul must now overlay chrome://browser/content/devtools/debugger.xul. You may add references to both these files in chrome.manifest for compatibility.

See also

Older versions

{{Firefox_for_developers('22')}}

Revision Source

<p>Want to help document Firefox 23? See the <a class="external" href="http://beta.elchi3.de/doctracker/#list=fx&amp;version=23.0">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="Security">Security</h3>
<ul>
  <li>Mixed content blocking. Firefox will no longer load non-secure (http) resources on secure (https) pages ({{bug(834836)}}).</li>
  <li>The standard syntax of <a href="/en-US/docs/Security/CSP" title="/en-US/docs/Security/CSP">CSP</a> 1.0 policies are now implemented and enforced by default.</li>
</ul>
<h3 id="Developer_Tools">Developer Tools</h3>
<ul>
  <li>A Network Panel has been added to the developer tools. This is more detailed view than the "Net" view option in the Web Console.</li>
  <li>Web Console has been renamed "Console", and includes the option to filter security errors/warnings.</li>
  <li>The new Toolbox Options lets you disable features, change light/dark theme, or enable Chrome/Remote debugging.</li>
</ul>
<h3 id="HTML">HTML</h3>
<ul>
  <li>The {{HTMLElement("blink")}} element support is now completely dropped. The <code>&lt;blink&gt;</code> tag now implements the {{domxref("HTMLUnknownElement")}} interface ({{bug(857820)}}).</li>
  <li>The <code>range</code> state of the {{HTMLElement("input")}} element (<code>&lt;input type="range"&gt;</code>) has been switched on by default ({{bug(841950)}}).</li>
</ul>
<h3 id="JavaScript">JavaScript</h3>
<ul>
  <li>The <a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/defineProperty" title="/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/defineProperty"><code>Object.defineProperty</code></a> method can now be used to redefine the <code>length</code> property of an <a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array" title="/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array"><code>Array</code></a> object.</li>
  <li>The option to disable JavaScript, including the options to allow moving windows/replace context menu, have been removed. You may still disable JavaScript by double clicking the "javascript.enabled" option in about:config.</li>
</ul>
<h3 id="DOM">DOM</h3>
<ul>
  <li>D3E <a href="/en-US/docs/DOM/KeyboardEvent#Key_names_and_Char_values" title="/en-US/docs/DOM/KeyboardEvent#Key_names_and_Char_values"><code>KeyboardEvent.key</code></a> is now supported, but only for non-printable keys ({{bug(842927)}}).</li>
  <li>The <code>title</code> attribute of {{domxref("DOMImplementation.createHTMLDocument")}} is now optional as per updated DOM specification.</li>
  <li>The ability to add a sidebar panel (<code>window.sidebar.addPanel</code>) has been dropped ({{bug(691647)}}).</li>
  <li>The unprefixed {{domxref("window.requestAnimationFrame")}} and {{domxref("window.cancelAnimationFrame")}} methods has been added. ({{bug(704063)}})</li>
  <li>The text argument for {{domxref("window.alert")}} and {{domxref("window.confirm")}} is now optional ({{bug(861605)}}).</li>
  <li>The {{domxref("HTMLMediaElement.initialTime")}} property, removed from the spec, is no more supported ({{bug(742537)}}).</li>
  <li>The {{domxref("AnimationEvent.AnimationEvent", "AnimationEvent()")}} constructor has been added ({{bug(848293)}}).</li>
  <li>The {{domxref("AnimationEvent.pseudoElement")}} property has been implemented ({{bug(848293)}}).</li>
  <li>The {{domxref("TransitionEvent.TransitionEvent", "TransitionEvent()")}} constructor has been added ({{bug(848291)}}).</li>
  <li>The {{domxref("TransitionEvent.pseudoElement")}} property has been implemented ({{bug(848291)}}).</li>
  <li>The non-standard {{domxref("TransitionEvent.initTransitionEvent()")}} and {{domxref("AnimationEvent.initAnimationEvent()")}} have been removed ({{bug(868751)}}).</li>
</ul>
<h3 id="CSS">CSS</h3>
<ul>
  <li>The blink effect for <code><a href="/en-US/docs/CSS/text-decoration" title="/en-US/docs/CSS/text-decoration">text-decoration</a>: blink;</code> has no more effect, but is still a valid value ({{bug(857820)}}).</li>
</ul>
<h3 id="MathML">MathML</h3>
<ul>
  <li>Negative widths for the {{MathMLElement("mspace")}} element has been implemented ({{bug(717546)}}).</li>
  <li>The {{MathMLElement("semantics")}} element now determines the visible child as described in the MathML3 specification.</li>
</ul>
<h2 id="Changes_for_addon_and_Mozilla_developers">Changes for addon and Mozilla developers</h2>
<h3 id="Firefox_developer_tools">Firefox developer tools</h3>
<p>Addons that overlay chrome://browser/content/debugger.xul must now overlay chrome://browser/content/devtools/debugger.xul. You may add references to both these files in chrome.manifest for compatibility.</p>
<h2 id="See_also">See also</h2>
<ul>
  <li><a href="http://www.mozilla.org/en-US/firefox/23.0a2/auroranotes/">Firefox 23 Aurora Notes</a></li>
  <li><a href="/en-US/docs/Site_Compatibility_for_Firefox_23">Site Compatibility for Firefox 23</a></li>
</ul>
<h3 id="Older_versions">Older versions</h3>
<p>{{Firefox_for_developers('22')}}</p>
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