Firefox 24 for developers
Changes for Web developers
CSS
- The two values
-moz-zoom-in
and-moz-zoom-out
of thecursor
property have been unprefixed tozoom-in
andzoom-out
(Firefox bug 772153). - To match the specification, the keywords
not
,only
,and
, andor
cannot be used as media types anymore (Firefox bug 757554).
HTML
- The
<track>
element has been implemented behind themedia.webvtt.enabled
preference, and is disabled by default. (Firefox bug 833385).
JavaScript
- Arrow functions are no longer automatically in strict mode unless explicitly requested with
"use strict"
(Firefox bug 852762). - The
String.prototype.repeat
JS method has been implemented (Firefox bug 815431). - The
Set.prototype.values()
,Set.prototype.keys()
andSet.prototype.entries()
methods onSet
objects have been implemented (Firefox bug 869996).
DOM
- Support for the
Range()
constructor has been added (Firefox bug 868999). - Support for the
Text()
constructor has been added (Firefox bug 869000). - Support for the
Comment()
constructor has been added (Firefox bug 869006). - Support for the
DocumentFragment()
constructor has been added (Firefox bug 869002). - The
FocusEvent
interface has been implemented (Firefox bug 855741). - Support for the
ChildNode.remove()
method has been added (Firefox bug 856629). - The WebVTT interfaces related to the
<track>
element,HTMLTrackElement
,TextTrack
,TextTrackCue
,TextTrackList
, andTextTrackCueList
have been implemented behind themedia.webvtt.enabled
property, defaulting tofalse
(Firefox bug 833385). - The
Gamepad
interface, andNavigator.getGamepads
have been implemented behind thedom.gamepad.enabled
property, defaulting tofalse
(Firefox bug 690935). - On desktop Firefox only,
HTMLCanvasElement.getContext()
can now take thewebgl
value, in addition toexperimental-webgl
(Firefox bug 870232). - The non-standard method
mozLoadFrom()
ofHTMLMediaElement
has been removed (Firefox 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).
- The source map syntax has been changed to use
//#
instead of//@
(Firefox bug 870361).
MathML
- The
dir
attribute for controlling directionality of formulas on e.g.<math>
or<mrow>
elements is now equivalent to using thedirection
CSS property. - The equal sign ("=") is now stretchable.
- The "
updiagonalarrow
" value for thenotation
attribute on<menclose>
elements has been added.
Changes for add-on and Mozilla developers
- Doc Shells have now the
allowMedia
attribute to disable media playing (Firefox bug 759964). - Sherlock search plugins in the application directory or profile won't be loaded anymore (Firefox bug 862143).
See also
Older versions
- Firefox 23 for developers
- Firefox 22 for developers
- Firefox 21 for developers
- Firefox 20 for developers
- Firefox 19 for developers
- Firefox 18 for developers
- Firefox 17 for developers
- Firefox 16 for developers
- Firefox 15 for developers
- Firefox 14 for developers
- Firefox 13 for developers
- Firefox 12 for developers
- Firefox 11 for developers
- Firefox 10 for developers
- Firefox 9 for developers
- Firefox 8 for developers
- Firefox 7 for developers
- Firefox 6 for developers
- Firefox 5 for developers
- Firefox 4 for developers
- Firefox 3.6 for developers
- Firefox 3.5 for developers
- Firefox 3 for developers
- Firefox 2 for developers
- Firefox 1.5 for developers