Firefox 33 for developers

Firefox 33 was released on October 14, 2014. This article lists key changes that are useful not only for web developers, but also Firefox and Gecko developers as well as add-on developers.

Changes for Web developers

Developer Tools

Highlights

• Event listeners popup
• @media sidebar
• Add new rule
• Edit keyframes
• Cubic bezier editor
• Transform highlighter
• Persistent disable cache
• New Commands
• Editor preferences
• WebIDE

For details please see the hacks post. Special thanks to the 33 contributors that added all the features and fixes in this release.

CSS

• Implemented @counter-style rule (bug 966166).
• Unprefixed ethiopic-numeric, persian, arabic-indic, devanagari, bengali, gurmukhi, gujarati, oriya, tamil, telugu, kannada, malayalam, thai, lao, myanmar, khmer, cjk-heavenly-stem, cjk-earthly-branch in list-style-type (bug 985825 and bug 1063856).
• Added support for mongolian, disclosure-open and disclosure-closed counter styles in list-style-type (bug 982355 and bug 1063856).
• Fixed CSS animations with empty keyframes rule so they also dispatch events (bug 1004377).
• Added support for rebeccapurple, a new <color> name defined in CSS Colors level 4 (bug 1024642).
• Our experimental implementation of CSS Fonts Level 3 progresses. Its activation is governed by the the layout.css.font-features.enabled preference, enabled by default in Nightly. Newly implemented features are:
  • The fallback algorithm of font-variant-caps, creating synthetic alternates for missing glyphs (bug 961558).
  • The font-synthesis CSS property has been implemented (bug 871453).

HTML

• Added the experimental support for <picture> element (bug 870022), behind the dom.image.picture.enabled preference (off by default).
• The <label>, especially without a for attribute, doesn't apply anymore to a <input type=hidden> field (bug 597650). The previous behavior wasn't spec compliant.
• The link annotation noreferrer has been implemented on <a> elements. <a rel="noreferrer"> will not include the URL of the referrer in the HTTP request sent to fetch it (bug 530396). Note that this work only for in-page links, not for linked clicked via the UI, like via contextual menus.
• On Android, support for two new values for the name attribute of <meta> has been added: msapplication-TileImage and msapplication-TileColor (bug 1014712).
  Example:
  <meta name="msapplication-TileImage" content="images/benthepcguy-144.png"/>
<meta name="msapplication-TileColor" content="#d83434"/>

JavaScript

• The non-standard method Number.toInteger() has been removed (bug 1022396).
• The Map.prototype.set(), WeakMap.prototype.set() and Set.prototype.add() methods are now chainable, return their equivalent objects and no longer undefined (bug 1031632).
• A default parameter is evaluated before function declarations inside the function body, so those functions cannot be referred from default parameter (bug 1022962).
• Shorthand properties are now allowed in object literals: if not explicitly defined, property keys are initialized by variables of the same name. E.g. function f(x, y) { return {x, y}; } is equivalent to function f(x, y) { return {x: x, y: y}; } (bug 875002).
• The parsing of yield and yield* has been updated to conform with the latest ES6 specification (bug 981599).
• The non-standard hasOwn trap has been removed (bug 980565).

Interfaces/APIs/DOM

• The RadioNodeList API has been implemented and the selected radio button is accessible via RadioNodeList.value (bug 779723).
• The DOMMatrix has been added (bug 1018497).
• A non-standard (but implemented in other browsers) DOMException.stack property has been added. It returns a string with a human-friendly formatted stack (bug 857648), in the same format as the existing non-standard Error.stack property.
• For <canvas>, the method CanvasPattern.setTransform(), allowing to modify a pattern using the SVGMatrix representation of a linear transform (bug 1019257).
• Our experimental implementation of Media Source Extensions, behind the media.mediasource.enabled preference, enabled by default in Nightly and Aurora only, now supports MP4 (bug 1000686).
• The properties HTMLMediaElement.audioTracks and HTMLMediaElement.videoTracks have been experimentally implemented. They are controlled by the media.track.enabled, off by default (bug 744896).
• The non-standard XMLHttpRequest.mozBackgroundRequest() is no more accessible from Web sites. Only Firefox-internal code (Chrome code) can use it (bug 1035242).
• The touchenter and touchleave events, removed from the specification, have been removed (bug 1036444).
• The formely called loaded event, sent on a HTMLTrackElement has been renamed load to match the specification (bug 1035505).
• The IndexedDB interface FileHandle has been renamed in IDBMutableFile (bug 1006485).
• The IndexedDB interface LockedFile has been renamed in IDBFileHandle (bug 1006485).
• The ServiceWorker interface has been implemented, behind the dom.serviceWorkers.enabled flag (bug 903441).
• The NetworkInformation.type now also support the "unknown" value (bug 1023029).

MathML

• The attributes columnspacing, framespacing, and rowspacing of the <mtable> element are now supported (bug 330964).
• Use Open Type MATH constants for fractions, stacks, radicals, and scripts (bug 961365).

SVG

No change.

Audio/Video

No change.

WebGL

• EXT_blend_minmax is now exposed. It extends blending capabilities by adding two new blend equations: producing the minimum or maximum color components of the source and destination colors (bug 973815).

Security

• The CSP 1.1 frame-ancestors directive is now supported (bug 846978).

Changes for add-on and Mozilla developers

• The JavaScript Debugger Service (JSD) has been removed in favor of the new Debugger API (bug 800200).
• The interface nsIX509CertDB2 has been removed and the methods from that interface have been moved to the nsIX509CertDB interface.

Add-on SDK

Highlights

• Added support for context menus in panels via a new option in the Panel constructor.
• Added tab.readyState.
• Added a BrowserWindow parameter to sidebar.show() and sidebar.hide(), to control the window for which the sidebar will be shown or hidden.

Details

GitHub commits made between Firefox 32 and Firefox 33. This will not include any uplifts made after this release entered Aurora.

Bugs fixed between Firefox 32 and Firefox 33. This will not include any uplifts made after this release entered Aurora.

See also

• Site Compatibility for Firefox 33

Older versions