Firefox 25 for developers

Changes for Web developers

New in Firefox DevTools

• The inspector now features autocompletion for CSS names and values.
• The debugger now lets you "black box" script files, to prevent breakpoints from stopping in library code you're not interested in debugging.
• The Profiler now has the ability to save and import profiling results. "Show Gecko Platform Data" is now an option in the Firefox developer tools options.
• The Network panel has a right-click context menu, with copy and resend URL commands.
• Numerous under-the-hood changes may make some rewriting necessary for addons that modify the DevTools.

CSS

• The support for the keyword local as a value of the background-attachment CSS property has been added (bug 483446).
• Support of a non-standard Mozilla-only media query to determine the operating system version has been added: -moz-os-version (bug 810399). The property is currently only implemented on Windows.
• The -moz-osx-font-smoothing CSS property has been added (bug 857142).
• Our experimental support for filter now supports the hue-rotate() functional notation (bug 897392). It is still preffed off by default.

• page-break-inside: avoid is now working with the height of a block (bug 883676).

HTML

• The srcdoc attribute of <iframe>, allowing the inline specification of the content of an <iframe>, is now supported (bug 802895).
• When used with a "image/jpeg" type, the method HTMLCanvasElement.toBlob now accepts a third attribute defining the quality of the image (bug 891884).

JavaScript

EcmaScript 6 (Harmony) implementation continues!

• The method Array.of() is now implemented on Array (bug 866849).
• Support for the methods Array.prototype.find() and Array.prototype.findIndex() has been added (bug 885553).
• The methods Number.parseInt() and Number.parseFloat() have been implemented (bug 886949)
• The methods Map.prototype.forEach() and Set.prototype.forEach() are now implemented (bug 866847).
• New mathematical methods have been implemented on Math: Math.log10(), Math.log2(), Math.log1p(), Math.expm1(), Math.cosh(), Math.sinh(), Math.tanh(), Math.acosh(), Math.asinh(), Math.atanh(), Math.trunc(), Math.sign() and Math.cbrt() (bug 717379).
• Support for binary and octal integer literals has been added: 0b10101010, 0B1010, 0o777, 0O237 are now valid (bug 894026).
• The machine epsilon constant, that is the smallest representible number that added to 1 will not be 1, is now available as Number.EPSILON (bug 885798).
• Typed arrays have been updated to no longer search in the prototype chain for indexed properties (bug 829896).

Interfaces/APIs/DOM

• The Web Audio API is now supported. An incomplete implementation was previously available behind a preference (bug 779297).
• Some IME related keys on Windows are supported by KeyboardEvent.key (bug 865565), see the key name table for the detail.
• Firefox for Metro now dispatches key events in the same way as the desktop version (bug 843236).
• keypress event is no longer dispatched if preventDefault() of preceding keydown event is called (bug 501496), see the document of keydown event for the detail.
• Renamed the Future interface to Promise (bug 884279).
• The srcDoc property on the HTMLIFrameElement interface, allowing the inline specification of the content of an <iframe>, is now supported (bug 802895).
• The createTBody() method on the HTMLTableElement interface, allowing to get its <tbody>, is now supported (bug 813034).
• The Range.collapse() method toStart parameter is now optional and default to false, like defined in the spec (bug 891340).
• Support of ParentNode interface on Document and DocumentFragment has been added (bug 895974).
• The previousElementSibling and nextElementSibling have been moved to ChildNode allowing them to be called not only on a Element object but also on a CharacterData or DocumentType object (bug 895974).
• The navigator.geolocation property has been updated to match the spec. It never returns null. When the preference geo.enabled is set to false, it now returns undefined (bug 884921).
• The videoPlaybackQuality attribute on the HTMLVideoElement interface has been changed to the getVideoPlaybackQuality method. (bug 889205)
• The non-standard GlobalObjectConstructor interface has been removed (bug 1089811). This interface was used to add arguments to the constructors of APIs that Firefox add-ons were exposing on the global object. This capability has been removed; note that at this time there's no replacement for this functionality.

MathML

No change.

SVG

No change.

See also

• Site Compatibility for Firefox 25

Older versions