Firefox 44 for developers

Установить Firefox Developer EditionFirefox 44 был выпущен 26 января 2016 года.
В этой статье перечислены ключевые изменения, которые полезны не только для веб-разработчиков, но и для разработчиков Firefox и Gecko, а также для разработчиков приложений.

Изменения, для Веб разработчиков

Инструменты разработчика

• Added keyboard shortcut S to scroll the selected node into view in the HTML pane of the Page Inspector (баг 1203147).

HTML

• <link rel="prefetch"> now obeys the crossorigin attribute (баг 1214819).

CSS

• position: fixed; now always creates a new stacking context (баг 1179288).
• The support of unicode-range has been enabled by default (баг 1119062).
• Our experimental implementation of CSS Writing Modes has been updated to reflect the latest specification:
  • The value sideways of the text-orientation property has been implemented and sideways-right has been made an alias of it (баг 1193488).
  • The value sideways-rl and sideways-lr of the writing-mode property (баг 1193488 and баг 1193519).
• The non-standard properties -moz-math-display and -moz-window-shadow are no more available from Web content (баг 1207002, баг 1211040, and баг 1212607).
• The font-style property now distinguishes between oblique and italic when both variants are available (баг 543715).
• Though not supported, the properties marks, orphans, page, size, and widows, were parsed and @supports was incorrectly reporting them as supported; this has been fixed and the properties are not parsed anymore, nor marked as supported (баг 1215702).
• The internal value -moz-mac-unified-toolbar has been removed from the possible values for the -moz-appearance property (баг 1206468).
• The font-style property now makes the distinction between oblique and italic: if both faces are present the correct one is now selected (баг 543715).

JavaScript

New APIs

• Symbol.toPrimitive, Symbol.prototype[@@toPrimitive], and Date.prototype[@@toPrimitive] have been implemented (баг 1054756).

Changes

• The let and const bindings in the global level have been made compliant with ES2015 semantics. See баг 589199 and the blog post "Breaking changes in let and const in Firefox Nightly 44". In addition, let is now available to default Web JavaScript (strict and non-strict) and does not require a version opt-in anymore (баг 932517).
• If typed arrays' (like Int8Array) and ArrayBuffer) constructors are called as a function without the new operator, a TypeError is now thrown as per the ES6 specification (баг 980945, баг 1214936).
• The RegExp sticky flag now follows the ES2015 standard for anchored sticky regular expressions (баг 773687).
• The JavaScript shell (SpiderMonkey's REPL) now defaults to the default, Web-compatible JS version (and not JS1.7+ anymore) (баг 1192329).

Removals

• Support for the non-standard let blocks has been dropped (баг 1167029.
• The non-standard and deprecated property Object.prototype.__noSuchMethod__ has been removed (баг 683218).

Interfaces/APIs/DOM

DOM & HTML DOM

• For compatibility with specific existing sites, the property Document.charset has been implemented as an alias of Document.characterSet (баг 647621).
• Support for the window.sidebar.addSearchEngine() method, which allowed Web pages to invoke an installation of a Sherlock plugin, has been dropped and now it just logs a warning in the Web Console (баг 862148).
• To fight unwanted pop-ups, prompts requested in Window.onbeforeunload of pages that have not been interacted with are no more displayed (баг 636905).
• The deprecated method MessageEvent.initMessageEvent() has been reimplemented for backward compatibility (баг 949376).
• The obsolete DocumentType.internalSubset has been removed (баг 801545).
• For compatibility with existing sites, the properties Window.orientation, Window.onorientationchange, as well as the orientationchange event have been implemented (баг 920734).
• Iframe with explicit fullscreen request should not exit fullscreen implicitly (баг 1187801).
• The events mouseover, mouseout, mouseenter, mouseleave, pointermove, pointerover, pointerout, pointerenter and pointerleave are now triggered for disabled form elements (баг 218093).
• The method Element.webkitMatchesSelector() has been added (баг 1216193).

• To match the spec, the method Document.createAttribute() now lowercases the input (баг 1176313).

WebGL

• Uniform Buffer Objects have been implemented (баг 1048747).

IndexedDB

• The IDBIndex.getAll() and IDBIndex.getAllKeys() are now available by default (баг 1196841).

Service Workers

• The ServiceWorkerMessageEvent and ExtendableMessageEvent interfaces have been implemented ({{ bug }} and баг 1207068).
• Headers objects now support a pair iterator, meaning that the methods Headers.entries(), Headers.keys(), and Headers.values() are now available; Symbol.iterator now also returns the default iterator for them (баг 1108181).
• The XMLHttpRequest API has been disabled on Service Workers ({{ bug }}).
• The interface FetchEvent now extends ExtendableEvent, giving it access to the ExtendableEvent.waitUntil() method. ({{ bug }}).
• Following a recent change in the specification, FetchEvent.client has been removed ({{ bug }}).
• To match the latest specification, the ServiceWorkerContainer.onreloadpage has been removed ({{ bug }}).
• The event handlers ServiceWorkerGlobalScope.onbeforeevicted and ServiceWorkerGlobalScope.onevicted have been removed as they weren't following the spec. They will be reintroduced in the future, but their removal will allow feature detection to work as expected ({{ bug }}).
• In the FetchEvent() constructor, if the isReload member is not present in the options dictionary, it now defaults to false ({{ bug }}).
• The Client.frameType property is now implemented on the right interface; it was on WindowClient before ({{ bug }}).
• When AppCache is used to provide offline support for a page, a warning message is now displayed in the console advising developers to use Service workers instead ({{ bug }}.)
• Service workers have been enabled by default in Gecko.

WebRTC

• WebRTC interfaces have been unprefixed ({{ bug }}). In particular:
  • mozRTCPeerConnection is now RTCPeerConnection.
  • mozRTCIceCandidate is now RTCIceCandidate.
  • mozRTCSessionDescription is now RTCSessionDescription.
• The RTCDataChannel.bufferedAmountLowThreshold and RTCDataChannel.onbufferedamountlow properties, as well as the bufferedamountlow event, have been implemented ({{ bug }}).
• The attribute RTCPeerConnection.canTrickleIceCandidates has been added, the non-standard method RTCPeerConnection.updateIce() removed ({{ bug }}).
• The MediaStream interface now supports the MediaStream.addTrack() and MediaStream.removeTrack() methods ({{ bug }}).
• The constructor MediaStream() has been implemented ({{ bug }}).

New APIs

• An experimental implementation of the Canvas API in Workers has landed: OfflineCanvas and HTMLCanvasElement.transferControlToOffscreen() are available behind the gfx.offscreencanvas.enabled preference, currently disabled by default ({{ bug }}).
• The Text2Speech API, part of Web Speech API, has now an OS X backend. But this is disabled by default ({{ bug }}).

Miscellaneous

• URLSearchParams objects now support a pair iterator, meaning that the methods URLSearchParams.entries(), URLSearchParams.keys(), and URLSearchParams.values() are now available; Symbol.iterator now also returns the default iterator for them ({{ bug }}).
• FormData objects now support a pair iterator, meaning that the methods FormData.entries(), FormData.keys, and FormData.values() are now available; Symbol.iterator now also returns the default iterator for them ({{ bug }}).
• When XMLHttpRequest.send() is used with an HTML document, it now uses text/html instead of application/xml ({{ bug }}).
• Speech synthesis (text-to-speech) has been implemented in Firefox Desktop for Mac and Linux, hidden behind the media.webspeech.synth.enabled flag in about:config ({{ bug }}, {{ bug }}.) See Web Speech API for more information.
• Elements inside a <frame> or an <object> can't be set full-screen anymore ({{ bug }}).

MathML

No change.

SVG

No change.

Audio/Video

No change.

HTTP

• Support for the Brotli algorithm has been added and both Accept-Encoding and Content-Encoding headers now support the br value ({{ bug }} and {{ bug }}).
• Incorrect support of HTTP/2 headers containing line breaks ('/n') have been removed as the spec doesn't allow it, unlike HTTP/1 ({{ bug }}).

Networking

No change.

Security

• RC4 is now also disabled by default on Beta and Release versions of the browser ({{ bug }}).

Changes for add-on and Mozilla developers

Interfaces

No change

XUL

No change.

JavaScript code modules

• Added LIKE support to Sqlite.jsm ({{ bug }}).
• Added Snackbars.jsm module to Firefox for Android ({{ bug }})

XPCOM

No change.

Other

No change.

See also

• Site compatibility for Firefox 44

Older versions