Site Compatibility for Firefox 23
Firefox 23 Aurora (pre-Beta) was released on . While it has been developed to maintain compatibility as much as possible, the new version includes some changes affecting backward compatibility aimed at improving interoperability with the other browsers or following the latest Web standards. Here's the list of such changes — Hope this helps whenever you test your sites or applications.
This article only explains the changes that may affect backward compatibility for Websites. For the other new features and changes, please read the following documents:
This list may be updated until the release of the final version on , so please check back later.
- Bug 857820 – Drop only blink effect from text-decoration: blink; and completely remove <blink> element
Firefox previously supported the Netscape-derived blink effect with the
blink keyword for the CSS
text-decoration property as well as the HTML
blink element and the DOM
String.blink method. Starting with Firefox 23, the blink effect no longer works. While
text-decoration:blink continues to be supported by the CSS parser and the DOM APIs, the HTML parser has dropped the
blink element support, thus the element will be treated as an unknown element. Internet Explorer, Chrome and Safari haven't supported the effect. Opera may also drop the support once it switches to the Blink rendering engine.
window.sidebar.addPersistentPanel are no longer supported. These methods were a part of a Netscape-derived API which allowed Web publishers to integrate their contents as sidebar panels of the browser. They were not standardized, rarely used, and not very well supported. No other browsers have implemented these.
- Bug 704063 – Add unprefixed requestAnimationFrame
- Bug 753453 – requestAnimationFrame callback should return DOMHighResTimeStamp
requestAnimationFrame, the unprefixed version of
mozRequestAnimationFrame, has been added. This unprefixed method passes a
DOMHighResTimeStamp to callbacks. It has microsecond precision and can be compared to
On the other hand, the prefixed method, which will be removed in the future, continues to pass an epoch-based
DOMTimeStamp to callbacks. The passed-in value has millisecond precision and can be compared to
- Bug 829872 – Consider returning null from contentDocument getters when the caller does not subsume the document
contentDocument property on frames now returns
null if the caller doesn't subsume the document. This change affects the
contentDocument property on the
object elements as well as the
getSVGDocument method on the
window.defaultStatus property is no longer available. Setting this property has had no effect in Firefox because the default preference has disallowed changes to the status text by Web pages. Recently, the Firefox UI dropped support for enabling that pref. Also, this property is not specified in the HTML5 spec.
window.status is still available.
- Bug 868751 – Remove support for document.createEvent("AnimationEvent"), document.createEvent("TransitionEvent"), AnimationEvent.initAnimationEvent, and TransitionEvent.initTransitionEvent
The support for obsolete
TransitionEvent.initTransitionEvent has been removed.
Audio Data API被废弃
HTMLMediaElement.initialTime property is no longer available, due to the removal from the spec.
Firefox 18 introduced preferences to block loading content from non-SSL (
http) sites on SSL (
https) pages. One of those preferences,
security.mixed_content.block_active_content is now enabled by default in order to enhance user security. That means insecure scripts, stylesheets, plug-in contents, inline frames, Web fonts and WebSockets are blocked on secure pages, and a notification is displayed instead. It will not block "display content" like images, videos or audio. See Tanvi Vyas' blog post for details.