Firefox 37 for developers

Firefox 37 was released on March 31st, 2015. 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:

• Security panel in the Network Monitor
• Animations panel in the Page Inspector
• Support for running a custom build step in WebIDE

All devtools bugs fixed between Firefox 36 and Firefox 37.

CSS

• display: contents is now activated by default (bug 1102374 and bug 1105369).
• CSS multi-column layout is now working on element with display: table-caption (bug 1109571).
• Relative positioning (position: relative) of table cells has been implemented (bug 35168).
• The quirks mode behavior of empty-cells has been removed: it now defaults to show like in standard mode (bug 1020400).

HTML

• The value <a rel="noreferrer"> now also works when the link is opened in new tab (bug 1031264).
• The '.' followed by the extension is now allowed in <input accept>: when used, a file selector filters with this given extension to be proposed to the user (bug 826176).

JavaScript

• The Map, Set, WeakMap and WeakSet constructors now ignore null iterable (bug 1092538).
• The Map, Set, WeakMap and WeakSet constructors now supports monkey-patched prototype.set or prototype.add (bug 804279).
• The Non-standard String.prototype.quote() method has been removed (bug 1103181).
• The RegExp.prototype.flags property has been implemented (bug 1108467).
• Several Array methods have been implemented for typed arrays as well:
  • The every() and some() methods (bug 1116390).
  • The find() and findIndex() methods (bug 1078975).
  • The fill() method (bug 1113722).
  • The indexOf() and lastIndexOf() methods (bug 1107601).
  • The join() method (bug 1115817).
  • The reduce() and reduceRight() methods (bug 1117350).
  • The reverse() method (bug 1111516).
  • The keys(), values(), and entries() methods (bug 1119217).
• ES2015 Proxy enumerate trap is implemented (bug 783829).
• The configurable attribute of the Function.length property is now true per the ES2015 specification (bug 911142).
• The development of ParallelJS (PJS) has been discontinued due to the limited future prospects, little attention and code complexity. The experimental implementation that had been enabled only on the Nightly channel, including the Array.prototype.mapPar, filterPar and reducePar methods, has been completely removed.

Interfaces/APIs/DOM

• The StereoPannerNode Web Audio node has been implemented (bug 1100349).
• The Promise-based version of OfflineAudioContext is now available (bug 1087944).
• The experimental, not activated by default, implementation of Service Workers progresses: ServiceWorkerGlobalScope.update() has been implemented bug 1065366.
• The IndexedDB API can now be used in Web workers (bug 701634).
• Our experimental implementation of WebGL 2.0 is going forward!
  • The WebGL2RenderingContext.getBufferSubData() method has been implemented to provide access to Buffer Objects (bug 1048731).
• In keeping with the evolving WebRTC specification, we have deprecated RTCIceServer.url in favor of RTCIceServer.urls, which lets you specify more than one URL for a given ICE server.
• Some key names of KeyboardEvent.key are changed for conforming the latest DOM Level 3 Events spec. See the tables of KeyboardEvent.key values in MDN. The green cells are new values. And purple values are still unstable. Be careful if you use them (meta bug for these changes is bug 900372).
• The Console interface is now working on ServiceWorker and SharedWorker. It was previously available but not working (bug 1058644).
• The value of KeyboardEvent.key was incorrectly being reported as "RomanCharacters" when the 英数 (Eisu) key was pressed. Now it correctly returns "Eisu".

MathML

No change.

SVG

• SVG2's <marker orient="auto-start-reverse"> has been implemented (bug 1107584).

Audio/Video

No change.

Networking

• WebSockets now supports the permessage compression method, if the server does support it (bug 792831).

Security

• The usage of weak protocols or ciphers, like SSL 3.0 and RC4, are now logged in the console, to warn sites that are using it (bug 1092835).
• The CSP 1.1 referrer directive is now supported (bug 965727).

Changes for add-on and Mozilla developers

Add-on SDK

No change.

XUL

No change.

See also

• Site Compatibility for Firefox 37

Older versions