Revision 1133181 of Firefox 52 for developers

<p>{{ReleaseChannelInfo("52", "52", "March 2017", "Nightly")}}</p>

<h2 id="Changes_for_Web_developers">Changes for Web developers</h2>

<h3 id="Developer_Tools">Developer Tools</h3>

<ul>
 <li>{{domxref("Console/groupCollapsed", "console.groupCollapsed()")}} now collapses the logged group as expected ({{bug(1088360)}}).</li>
</ul>

<h3 id="HTML">HTML</h3>

<p><em>No change.</em></p>

<h3 id="CSS">CSS</h3>

<ul>
 <li>Added {{cssxref(":focus-within")}} pseudo-class ({{bug(1176997)}}).</li>
 <li>{{cssxref("clip-path")}} shapes don't transition between percent and pixel coordinates ({{bug(1266570)}}).</li>
 <li>Add support for display:flex/grid and columnset layout inside &lt;button&gt; elements(we are the only modern web rendering engine to not have this particular behavior on &lt;button style="display:flex"&gt;. So from a web compatibility perspective, we should probably align with the other engines on this.) ({{bug(984869)}}).</li>
 <li>[css-grid] Implement Grid container Baselines ({{bug(1151204)}}).</li>
 <li>Implement interpolation between numeric color and currentcolor ({{bug(1299741)}}).</li>
 <li>Remove -moz-use-text-color from color properties ({{bug(1306214)}}).</li>
 <li>Unprefix css3 multi-column properties (and add back -moz prefixed versions as aliases, for now) ({{bug(1300895)}}).</li>
 <li>[css-flexbox] Implement flexbox layout for "{{cssxref("justify-content")}}: space-evenly" &amp; "{{cssxref("align-content")}}: space-evenly" ({{bug(1235922)}}).</li>
</ul>

<h3 id="JavaScript">JavaScript</h3>

<ul>
 <li>Added {{jsxref("Functions/rest_parameters", "rest parameter destructuring", "#Destructuring_rest_parameters", 1)}} ({{bug(1243717)}}).</li>
</ul>

<h3 id="InterfacesAPIsDOM">Interfaces/APIs/DOM</h3>

<h4 id="DOM_HTML_DOM">DOM &amp; HTML DOM</h4>

<ul>
 <li>Ship the selection events API ({{bug(1309612)}}).</li>
</ul>

<h4 id="Canvas">Canvas</h4>

<p><em>No change.</em></p>

<h4 id="WebGL">WebGL</h4>

<p><em>No change.</em></p>

<h4 id="IndexedDB">IndexedDB</h4>

<p><em>No change.</em></p>

<h4 id="Service_Workers">Service Workers</h4>

<p><em>No change.</em></p>

<h4 id="WebRTC">WebRTC</h4>

<ul>
 <li>The {{domxref("MediaDevices.ondevicechange")}} event handler and corresponding {{event("devicechange")}} event, which were implemented but disabled by default on Mac only in Firefox 51, have been implemented on Windows and Linux and are now enabled by default.</li>
</ul>

<h4 id="New_APIs">New APIs</h4>

<p><em>No change.</em></p>

<h4 id="Others">Others</h4>

<p><em>No change.</em></p>

<h3 id="MathML">MathML</h3>

<p><em>No change.</em></p>

<h3 id="SVG">SVG</h3>

<p><em>No change.</em></p>

<h3 id="AudioVideo">Audio/Video</h3>

<p><em>No change.</em></p>

<h2 id="HTTP">HTTP</h2>

<p><em>No change.</em></p>

<h2 id="Networking">Networking</h2>

<p><em>No change.</em></p>

<h2 id="Security">Security</h2>

<p><em>No change.</em></p>

<h2 id="Changes_for_add-on_and_Mozilla_developers">Changes for add-on and Mozilla developers</h2>

<h3 id="Interfaces">Interfaces</h3>

<ul>
 <li><code><a href="/en-US/docs/Mozilla/Tech/XPCOM/Reference/Interface/nsIDroppedLinkHandler">nsIDroppedLinkHandler</a>.dropLinks</code> method and <a href="/en-US/docs/Mozilla/Tech/XPCOM/Reference/Interface/nsIDroppedLinkItem">nsIDroppedLinkItem</a> interface have been added to handle dropping multiple items ({{bug(92737)}}).</li>
</ul>

<h3 id="XUL">XUL</h3>

<ul>
 <li><code><a href="/en-US/docs/Mozilla/Tech/XUL/tabbrowser">tabbrowser</a>.<a href="/en-US/docs/Mozilla/Tech/XUL/Method/loadTabs">loadTabs</a>(uris, params)</code> method overload has been added ({{bug(92737)}}).</li>
 <li><code><a href="/en-US/docs/Mozilla/Tech/XUL/browser">browser</a>.<a href="/en-US/docs/Mozilla/Tech/XUL/Attribute/droppedLinkHandler">droppedLinkHandler</a></code> function signature has been changed ({{bug(92737)}}).</li>
</ul>

<p><em>No change.</em></p>

<h3 id="JavaScript_code_modules">JavaScript code modules</h3>

<p><em>No change.</em></p>

<h3 id="XPCOM">XPCOM</h3>

<p><em>No change.</em></p>

<h3 id="Other">Other</h3>

<p><em>No change.</em></p>

<h2 id="See_also">See also</h2>

<ul>
 <li><a href="https://www.fxsitecompat.com/en-US/versions/52">Site Compatibility for Firefox 52</a></li>
</ul>

<h2 id="Older_versions">Older versions</h2>

<p>{{Firefox_for_developers(51)}}</p>