New developer features in Firefox 3.5

For web site and application developers

HTML 5 support

Using audio and video in Firefox

Firefox 3.5 adds support for the HTML 5 audio and video elements.

Offline resources in Firefox

Firefox 3.5 now fully supports the HTML 5 offline resource specification.

Drag and drop

The HTML 5 drag and drop API allows support for dragging and dropping items within and between web sites.  This also provides a simpler API for use by extensions and Mozilla-based applications.

Newly-supported CSS features

Downloadable fonts support

The new @font-face @rule lets web pages provide downloadable fonts, so that sites can be rendered exactly as the page author expects.

CSS media queries

Firefox 3.5 now supports CSS media queries, which enhance support for media-dependent style sheets.

::before and ::after updated to CSS 2.1

The ::before and ::after pseudo-elements have been updated to full CSS 2.1 support, adding support for the position, float, list-style-*, and some display properties.

opacity

The -moz-opacity Mozilla extension to CSS has been removed in favor of the standard opacity property.

text-shadow

The text-shadow property, which allows web content to specify shadow effects to apply to text and text decorations, is now supported.

word-wrap

This newly-supported property lets content specify whether or not lines may be broken within words in order to prevent overflow when an otherwise unbreakable string is too long to fit on one line.

-moz-box-shadow

-moz-border-image

-moz-column-rule

-moz-column-rule-width

-moz-column-rule-style

-moz-column-rule-color

-moz-column-gap

Firefox 3.5 adds support for these Mozilla extensions to CSS.

The -moz-nativehyperlinktext color value

This new color value represents the user's system's default hyperlink color.

The new -moz-window-shadow and -moz-system-metric(mac-graphite-theme) properties

These new CSS properties were added to facilitate theming.

New values for -moz-appearance

The -moz-win-glass and -moz-mac-unified-toolbar values have been added to -moz-appearance.

Using CSS transforms

Firefox 3.5 supports CSS transforms.  See -moz-transform and -moz-transform-origin for details.

:nth-child

:nth-last-child


:nth-of-type


:nth-last-of-type


:first-of-type


:last-of-type


:only-of-type

These selectors are all newly-supported in Firefox 3.5.

New DOM features

Using DOM workers

Firefox 3.5 supports DOM workers to allow easy multi-threading support in web applications.

Using geolocation

Firefox 3.5 supports the Geolocation API, which allows web applications to obtain information about the user's current location if a provider for that information is installed and enabled.

Using JSON in Firefox

Support for JSON is now integrated into the DOM.

Locating DOM elements using selectors

The selectors API allows querying a document to locate the elements that match a given selection rule.

The NodeIterator object

The NodeIterator object provides support for iterating over the list of the nodes in a DOM subtree.

The MozAfterPaint event

This new DOM event is sent after painting updates in windows.

The MozMousePixelScroll event

This new DOM event allows detection of pixel-based mouse scroll wheel events instead of line-based scroll events.

New JavaScript features

Object.getPrototypeOf()

This new method returns the prototype of a specified object.

New trim methods on the String object

The String object now has trim(), trimLeft(), and trimRight() methods.

Networking

Cross-site access controls for HTTP

In Firefox 3.5, it's now possible for HTTP requests, including those made by XMLHttpRequest, to work across domains if the server supports it.

Progress events for XMLHttpRequest

Progress events are now offered to enable extensions to monitor the progress of requests.

Improved Synchronous XMLHttpRequest support

DOM Timeout and Input Events are now suppressed during a synchronous XMLHttpRequest.

Controlling DNS prefetching

Firefox 3.5 provides DNS prefetching, whereby it performs domain name resolution ahead of time for links included in the current page, in order to save time when links are actually clicked.  This article describes how you can tune your web site to disable prefetching, or to adjust how prefetching operates.

New Canvas features

HTML 5 text API for canvas elements

Canvas elements now support the HTML 5 text API.

Shadow effects in a canvas

Canvas shadow effects are now supported.

moz-opaque attribute

Added the moz-opaque DOM attribute, which lets the canvas know whether or not translucency will be a factor.  If the canvas knows there's no translucency, painting performance can be optimized.

New SVG features

Applying SVG effects to HTML content

You can now apply SVG effects to HTML and XHTML content; this article describes how.

Miscellaneous new features

ICC color correction in Firefox

Firefox 3.5 now supports ICC color correction for tagged images.

The defer attribute is now supported on script elements

This attribute indicates to the browser that it may choose to continue to parse and render the page without waiting for the script to finish executing.

Other improvements

• The ch unit can now be used anywhere that accepts a unit of length; "1 ch" is the width of the "0" character.
• The white-space property now accepts the pre-line value.
• The Text node's wholeText property and replaceWholeText() method have been implemented.
• The property element.children has been added. It returns a collection of child elements of the given element.
• The Element Traversal API is now supported by the DOM Element object.
• HTML nodes may now be cloned using cloneNode().
• Dispatched DOM events can now be re-dispatched.  This makes Firefox 3.5 pass Acid 3 test 30.
• Improvements have been made to DOM 2 Range handling.
• In non-chrome scope, caught objects in exceptions are now the actual thrown object instead of an XPConnect wrapper containing the thrown object.
• SVG ID references are now live.
• SVG filters now work for foreignObject.
• The GetSVGDocument() method has been added to object and iframe elements for compatibility.

For XUL and add-on developers

If you're an extension developer, you should start by reading Updating extensions for Firefox 3.5, which offers a helpful overview of what changes may affect your extension.

New components and functionality

Supporting private browsing mode

Firefox 3.5 offers Private Browsing mode, which doesn't record the user's activities.  Extensions may support private browsing following the guidelines offered by this article.

Security changes in Firefox 3.5

This article covers security-related changes in Firefox 3.5.

Theme changes in Firefox 3.5

This article covers theme-related changes in Firefox 3.5.