Firefox 3.5 for developers
Firefox 3.5 (released June 30, 2009) introduces a number of new features, as well as additional and improved support for a wide variety of web standards. This article offers an extensive list, with links to articles covering the major improvements.
HTML 5 support
- Using audio and video
- 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
@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.
::afterupdated to CSS 2.1
::afterpseudo-elements have been updated to full CSS 2.1 support, adding support for the
list-style-*, and some
chunits for length
chunit can now be used anywhere that accepts a unit of length.
1chis the width of the "0" (zero) character.
-moz-opacityMozilla extension to CSS has been removed in favor of the standard
text-shadowproperty, which allows web content to specify shadow effects to apply to text and text decorations, is now supported.
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.
white-spaceproperty supports the
white-spaceproperty now accepts the
Firefox 3.5 adds support for these Mozilla extensions to CSS.
This new color value represents the user's system's default hyperlink color.
-moz-window-shadowproperty and the
These new CSS features were added to facilitate theming.
- New values for
-moz-mac-unified-toolbarvalues have been added to
- Using CSS transforms
These selectors are all newly-supported in Firefox 3.5.
New DOM features
Firefox 3.5 adds support for the Web Storage
localStorageproperty, which provides a way for web applications to store data locally on the client's computer.
- Using web workers
Firefox 3.5 supports web 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.
- Locating DOM elements using selectors
The selectors API allows querying a document to locate the elements that match a given selection rule.
- Mouse gesture events
Firefox 3.5 supports mouse gesture events such as trackpad swipes.
NodeIteratorobject provides support for iterating over the list of the nodes in a DOM subtree.
This new DOM event is sent after painting updates in windows.
This new DOM event allows detection of pixel-based mouse scroll wheel events instead of line-based scroll events.
This new method returns the prototype of a specified object.
- Using native JSON
Firefox 3.5 has native support for JSON.
- New trim methods on the String object
- 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
Progress events are now offered to enable extensions to monitor the progress of requests.
- Improved Synchronous
- 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 now support the HTML 5 text API.
- Shadow effects in a
Canvas shadow effects are now supported.
The canvas method
createImageData()is now supported, allowing code to specifically create an
ImageDataobject instead of requiring it to be done automatically. This can improve performance of other
ImageDatamethods by preventing them from having to create the object.
moz-opaqueattribute, 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. See also
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.
deferattribute is now supported on
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.
- The Text node's
Text.replaceWholeText()method have been implemented.
- The property
element.childrenhas been added. It returns a collection of child elements of the given element.
- The property
HTMLElement.contentEditableis now supported, to support editable elements.
- The Element Traversal API is now supported by the DOM Element object.
- HTML document nodes may now be cloned using
- The non-standard
getBoxObjectFor()DOM method has been removed. You should be using
- 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
XPConnectwrapper containing the thrown object.
- SVG ID references are now live.
- SVG filters now work for
GetSVGDocument()method has been added to
iframeelements for compatibility.
gDownloadLastDir.pathvariable has been renamed to
gDownloadLastDir.filesince it refers to an
nsIFile, not a path.
gDownloadLastDirPathvariable has been renamed to
gDownloadLastDirFilesince it refers to an
nsIFile, not a path.
- Starting in Firefox 3.5, you can no longer use
data:bindings in chrome packages that get
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.
- Monitoring Wi-Fi access points
Code with UniversalXPConnect privileges can now monitor the list of available access points, getting information on their SSIDs, MAC addresses, and signal strength. This can be used in tandem with Geolocation to offer Wi-Fi-based location service.
Notable changes and improvements
- The XUL
textboxwidget now offers a
searchtype, for use as search fields.
- In order to support dragging and dropping tabs between windows, the
browserwidget now has a
- Added the
levelattribute to the
panelelement; this specifies whether panels appear on top of other applications, or just on top of the window the panel is contained within.
- XUL elements now support the
keysetnow include a
- In addition,
keysets can now be removed using the node's
initialize()method removed; consumers should use the
createStatement()method instead to get a new statement object.
- The Storage API now offers support for asynchronous requests.
nsICookie2interface now exposes the time at which cookies were created in its new
- Added a flag to
URI_IS_LOCAL_RESOURCE) that is checked during chrome registration to make sure a protocol is allowed to be registered.
- Firefox now looks for plugins in
/usr/lib/mozilla/pluginson Linux, as well as the previously supported locations.
- The plugin API has been updated to include support for private browsing mode; you may now use
NPN_GetValue()to query the state of private browsing mode using the variable
- Location aware browsing
If you choose, you may allow Firefox 3.5 to share information about your current location with web sites. Firefox 3.5 can use information about the network you're connected to in order to share your location. Of course, it asks for your permission before doing so, to ensure your privacy.
- Open audio and video support
Firefox 3.5 supports embedded video and audio using the open Ogg format, as well as WAV for audio. No plugins, no confusing error messages about needing to install something or other that turns out not to be available on your platform anyway.
- Local data storage
Web applications can now use Web Storage's local storage capabilities to store data on your computer. This is great for anything from site preferences to more complex data.
- Private Browsing
Need to use someone else's computer? Switch on Private Browsing mode and nothing will be recorded about your session, including cookies, history, and any other potentially private information.
- Better privacy controls
The Privacy preference pane has been completely redesigned to offer users more control over their private information. Users can choose to retain or discard anything including history information, cookies, downloads, and form field information. In addition, users can specify whether or not to include history and/or bookmarks in the location bar's automated suggestions, so you can keep private web addresses from popping up unexpectedly while typing in the location bar.
- Faster page rendering
Web content draws faster in Firefox 3.5, thanks to technologies such as "speculative parsing." Your users don't need to know what it means, other than "it makes things draw faster."