Revision 331151 of Firefox 19 for developers

  • Revision slug: Firefox_19_for_developers
  • Revision title: Firefox 19 for developers
  • Revision id: 331151
  • Created:
  • Creator: trevorh
  • Is current revision? No
  • Comment element.getElementsByTagName now returns HTMLCollection

Revision Content

{{ draft() }}

{{ ReleaseChannelInfo("19", "19", "February 2013", "Nightly") }}

Want to help document Firefox 19? See the list of bugs that need to be written about and pitch in!

Changes for Web developers

Javascript

  • Map and Set objects have changed from having a size() method to a size property ({{bug("807001")}})

CSS

  • Support for the viewport-relative {{xref_csslength()}} units, vh, vw, vmin, and vmax, has landed ({{bug("503720")}})
  • CSS Flexbox has been unprefixed, yet disabled by default ({{bug("801098")}}).
  • The -moz-initial value has been unprefixed ({{bug("806068")}}). -moz-initial will be kept for a while as an alias; however, authors are strongly encouraged to switch over to initial.
  • The CSS {{ cssxref("text-transform")}} property now supports the full-width keyword allowing to add smoothly Latin characters inside a text using ideographic fixed width characters, like Chinese or Japanese ({{bug("774560")}}).
  • The CSS {{ cssxref("page-break-inside")}} has been implemented ({{bug("685012")}}).
  • The CSS {{ cssxref("calc", "calc()")}} function can now be used on <color-stop> (on {{xref_cssgradient()}}).
  • The CSS {{ cssxref("@page") }} at-rule is now supported ({{bug("115199")}}). Note that the pseudo-classes {{cssxref(":first")}}, {{cssxref(":right")}}, and {{cssxref(":left")}} are not yet implemented.

DOM

  • The {{ domxref("element.getElementsByTagName") }} method will now return HTMLCollection ({{bug("799464")}}).

Changes for add-on and Mozilla developers

Note: A key change in Firefox 19 is that nsresult is now strongly typed. This will help make it easier to detect bugs that are caused by mishandling of return values, but may cause existing code to break if it's making incorrect assumptions in this regard.

See also

{{Firefox_for_developers('18')}}

Revision Source

<p>{{ draft() }}</p>
<p>{{ ReleaseChannelInfo("19", "19", "February 2013", "Nightly") }}</p>
<p>Want to help document Firefox 19? See the <a class="external" href="http://beta.elchi3.de/doctracker/#list=fx&amp;version=19.0">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="Javascript">Javascript</h3>
<ul>
  <li><a href="/en-US/docs/JavaScript/Reference/Global_Objects/Map" title="/en-US/docs/JavaScript/Reference/Global_Objects/Map">Map</a> and <a href="/en-US/docs/JavaScript/Reference/Global_Objects/Set" title="/en-US/docs/JavaScript/Reference/Global_Objects/Set">Set</a> objects have changed from having a <code>size()</code> method to a <code>size</code> property ({{bug("807001")}})</li>
</ul>
<h3 id="CSS">CSS</h3>
<ul>
  <li>Support for the viewport-relative {{xref_csslength()}} units, <code>vh</code>, <code>vw</code>, <code>vmin</code>, and <code>vmax</code>, has landed ({{bug("503720")}})</li>
  <li>CSS Flexbox has been unprefixed, yet disabled by default ({{bug("801098")}}).</li>
  <li>The <code>-moz-initial</code> value has been unprefixed ({{bug("806068")}}). <code>-moz-initial</code> will be kept for a while as an alias; however, authors are strongly encouraged to switch over to <code>initial</code>.</li>
  <li>The CSS {{ cssxref("text-transform")}} property now supports the <code>full-width</code> keyword allowing to add smoothly Latin characters inside a text using ideographic fixed width characters, like Chinese or Japanese ({{bug("774560")}}).</li>
  <li>The CSS {{ cssxref("page-break-inside")}} has been implemented ({{bug("685012")}}).</li>
  <li>The CSS {{ cssxref("calc", "calc()")}} function can now be used on <code>&lt;color-stop&gt;</code> (on {{xref_cssgradient()}}).</li>
  <li>The CSS {{ cssxref("@page") }} at-rule is now supported ({{bug("115199")}}). Note that the pseudo-classes {{cssxref(":first")}}, {{cssxref(":right")}}, and {{cssxref(":left")}} are not yet implemented.</li>
</ul>
<h3 id="DOM">DOM</h3>
<ul>
  <li>The {{ domxref("element.getElementsByTagName") }} method will now return <code>HTMLCollection</code> ({{bug("799464")}}).</li>
</ul>
<h2 id="Changes_for_add-on_and_Mozilla_developers">Changes for add-on and Mozilla developers</h2>
<div class="note">
  <p><strong>Note:</strong> A key change in Firefox 19 is that <a href="/en-US/docs/XPCOM_API_Reference/nsresult" title="/en-US/docs/XPCOM_API_Reference/nsresult"><code>nsresult</code></a> is now strongly typed. This will help make it easier to detect bugs that are caused by mishandling of return values, but may cause existing code to break if it's making incorrect assumptions in this regard.</p>
</div>
<h2 id="See_also">See also</h2>
<p>{{Firefox_for_developers('18')}}</p>
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