Firefox 18 for developers
Firefox 18 was released on January 8, 2013. 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
HTML
- The
reversed
attribute of the<ol>
element is now supported (Firefox bug 601912). - The
crossorigin
attribute of the<link>
element is now supported (Firefox bug 786564). - The
allowfullscreen
attribute of the<iframe>
has been implemented and it's prefixed predecessormozallowfullscreen
is now deprecated.
CSS
- The
min-width
andmin-height
now uses theauto
keyword as initial value (This has an effect only on flex items as it resolves to0
, the previous initial value, for other items). (Firefox bug 763689) - The cascade has been updated: now author
!important
rules override CSS animations. (Firefox bug 783714) - The
background
shorthand property now recognizes CSS3background-size
property specified inside. (Firefox bug 570326) - Initial support for the CSS Flexbox Module has been landed. It is disabled by default but can be enabled by setting
layout.css.flexbox.enabled
to true (Firefox bug 666041).
DOM/APIs
navigator.mozPay
has been landed. (Firefox bug 767818)window.devicePixelRatio
has been landed. (Firefox bug 564815)- The MacOS X backend for
window.navigator.battery
has been implemented. (Firefox bug 696045) MozBlobBuilder
is removed. Developers need to useBlob
constructor for creating aBlob
object. (Firefox bug 744907)- The
visibilitychange
event and the Page Visibility API has been unprefixed (Firefox bug 812086). TextDecoder
andTextEncoder
have been added. Note that the implementation and spec of these evolved and have been changed in Firefox 19 (Firefox bug 764234).HTMLMediaElement.src
has been separate in two properties: the standardsrc
property, dealing with strings, and the prefixedmozSrcObject
property, dealing with media streams (Firefox bug 792665).- Support for transferable objects.
- The
Screen.lockOrientation()
method now supports anArray
of strings as argument (Firefox bug 784549.
JavaScript
- Harmony's (ECMAScript 2015) Direct Proxies have been landed (Firefox bug 703537). Warning: the implementation contains a couple of known bugs, missing features and misalignments with the current state of the spec. Do not rely on it for production code.
- The ECMAScript 2015
contains()
method is now implemented on strings. This is unfortunately not compatible with Mootools 1.2, which expects different behavior fromcontains()
on strings but does not ensure it. Newer versions of Mootools fix this issue; sites should upgrade their Mootools version to something newer than 1.2.
WebGL
- The prefixed version of the
EXT_texture_filter_anisotropic
WebGL extension, "MOZ_EXT_texture_filter_anisotropic" has been removed (Firefox bug 790946).
SVG
MathML
XUL
Network
- Quality factors ("q-values") are now clamped to 2 digits (e.g. in HTTP
Accept-Language
headers) (Firefox bug 672448). - The
ALLOW-FROM
syntax of theX-FRAME-OPTIONS
HTTP Response header is now supported (Firefox bug 690168).
Developer tools
Changes for add-on and Mozilla developers
Interface changes
nsIStreamListener
-
The 4th parameter (aOffset) of
onDataAvailable()
method changes to unsigned long long. (Firefox bug 784912) nsIUploadChannel
-
setUploadStream()
supports over 2GB content-length (Firefox bug 790617) nsIEditor
-
addEditorObserver()
has been removed, usesetEditorObserver()
instead,removeEditorObserver()
no longer takes ansIEditorObserver
parameter (Firefox bug 785091) nsIHttpProtocolHandler
-
http-on-modify-request
observers are no longer guaranteed to be called synchronously duringnsIChannel.asyncOpen()
. For observers that need to be called duringasyncOpen()
, the newhttp-on-opening-request
observer topic has been added.See
(Firefox bug 800799) nsIProtocolProxyService
-
The
resolve
method has been removed. Now, only theasyncResolve
method can be used. See (Firefox bug 769764)
New interfaces
Removed interfaces
The following interfaces have been removed.
nsIEditorObserver
See also
- Firefox 18 Beta Release Notes
- Aurora 18: HiDPI & Touch Events (Mozilla Hacks)
- Add-on Compatibility for Firefox 18 (Add-ons Blog)
Older versions
- 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