---
title: Firefox 7 技術文件
slug: Mozilla/Firefox/Releases/7
translation_of: Mozilla/Firefox/Releases/7
---
<div>{{FirefoxSidebar}}</div><p>Firefox 7 shipped on September 27, 2011. This article provides information about the changes that affect developers -- both of web content and of Firefox add-ons.</p>
<h2 id="Changes_for_web_developers">Changes for web developers</h2>
<h3 id="HTML">HTML</h3>
<ul>
 <li>The {{ domxref("HTMLHeadElement") }} <code>profile</code> property has been removed, this property has been deprecated since {{ gecko("2.0") }}.</li>
 <li>The {{ domxref("HTMLImageElement") }} <code>x</code> and <code>y</code> properties have been removed.</li>
 <li>The {{ domxref("HTMLSelectElement") }} <code>add()</code> method <code>before</code> parameter is now optional.</li>
 <li>The {{ HTMLElement("body") }} element's {{ htmlattrxref("background", "body") }} attribute is no longer resolved as a URI; this is in compliance with the current HTML specification.</li>
 <li>The {{ HTMLElement("option") }} element's {{ htmlattrxref("label", "option") }} attribute now reflects the value of the element's text content if the attribute isn't specified.</li>
</ul>
<h4 id="Canvas">Canvas</h4>
<ul>
 <li>As part of the <a class="external" href="http://blog.mozilla.com/joe/2011/04/26/introducing-the-azure-project/">Azure project</a> the Direct2D Azure Backend <a class="link-https" href="https://bugzilla.mozilla.org/show_bug.cgi?id=651858">has been implemented</a> and will significantly improve the performance of the 2D canvas.</li>
 <li>Specifying invalid values when calling <code>setTransform()</code>, <code>bezierCurveTo()</code>, or <code>arcTo()</code> no longer throws an exception; these calls are now correctly silently ignored.</li>
 <li>The <a href="/en/DOM/CanvasRenderingContext2D#isPointInPath()" title="en/DOM/CanvasRenderingContext2D#isPointInPath()"><code>isPointInPath()</code></a> method now correctly considers the transformation matrix when comparing the specified point to the current path.</li>
 <li>Calling <code>strokeRect()</code> with a zero width and height now correctly does nothing.</li>
 <li>Calling <a href="/en/DOM/CanvasRenderingContext2D#drawImage()" title="en/DOM/CanvasRenderingContext2D#drawImage()"><code>drawImage()</code></a> with a zero width or height {{ HTMLElement("canvas") }} now throws <code>INVALID_STATE_ERR</code>.</li>
 <li>Calling <a href="/en/DOM/CanvasRenderingContext2D#drawImage()" title="en/DOM/CanvasRenderingContext2D#drawImage()"><code>drawImage()</code></a> with non-finite coordinates no longer throws an exception.</li>
 <li><code>toDataURL()</code> method now accepts a second argument to control JPEG quality.</li>
 <li>Support for the non-standard <code>globalCompositeOperation</code> operations <code>clear</code> and <code>over</code> has been removed.</li>
 <li><a href="/en/Canvas_tutorial/Applying_styles_and_colors#Shadows" title="en/Canvas_tutorial/Applying_styles_and_colors#Shadows">Shadows</a> are now only drawn for <code>source-over</code> compositing operations.</li>
 <li>You can now configure the fill rule used by canvas by setting the <code>mozFillRule </code><a href="/en/DOM/CanvasRenderingContext2D#Attributes" title="en/DOM/CanvasRenderingContext2D#Attributes">attribute</a> on the context.</li>
 <li>Support for the experimental <code>mozDash</code>, <code>mozDashOffset</code>, <code>mozCurrentTransform</code> and <code>mozCurrentTransformInverse</code> attributes has been added.</li>
 <li>Support for the non-standard methods <code>mozDrawText()</code>, <code>mozMeasureText()</code>, <code>mozPathText()</code> and <code>mozTextAlongPath()</code> has been been removed.</li>
</ul>
<h3 id="CSS">CSS</h3>
<ul>
 <li>{{ cssxref("text-overflow") }} is now supported.</li>
 <li>The {{ cssxref("orient", "-moz-orient") }} property has been fixed so that {{ HTMLElement("progress") }} elements that are vertically oriented have appropriate default dimensions.</li>
</ul>
<h3 id="MathML">MathML</h3>
<ul>
 <li>XLink href has been restored and the MathML3 <code>href</code> attribute is now supported. Developers are encouraged to move to the latter syntax.</li>
 <li>Support for the <code>voffset</code> attribute on {{ MathMLElement("mpadded") }} elements has been added and behavior of <code>lspace</code> attribute has been fixed.</li>
 <li>The top-level {{ MathMLElement("math") }} element now accepts any attributes of the {{ MathMLElement("mstyle") }} element.</li>
 <li>Support for <a class="external" href="http://www.ctan.org/tex-archive/fonts/Asana-Math/">Asana Math</a> fonts has been added.</li>
 <li>The <code>medium</code> line thickness of fraction bars in {{ MathMLElement("mfrac") }} elements has been corrected to match the default thickness.</li>
 <li><a href="/en/MathML/Attributes/Values#Constants_(namedspaces)" title="en/MathML/Attributes/Values#Constants_(namedspaces)">Names for negative spaces</a> are now supported.</li>
</ul>
<h3 id="DOM">DOM</h3>
<ul>
 <li>The {{ domxref("File") }} interface's non-standard methods <code>getAsBinary()</code>, <code>getAsDataURL()</code>, and <code>getAsText()</code> have been removed as well as the non-standard properties <code>fileName</code> and <code>fileSize</code>.</li>
 <li>The {{ domxref("XMLHttpRequest/FormData", "FormData") }} interface no longer reports the filename as an empty string when sending the <code>Content-Disposition</code> HTTP header if the data was set using a {{ domxref("Blob") }}. This fixes errors that were happening with some servers.</li>
 <li>The {{ domxref("element.dir") }} attribute now always returns its result as all lower-case, as required by the HTML specification.</li>
 <li>The {{ domxref("FileReader") }} <code>readAsArrayBuffer()</code> method is now implemented.</li>
 <li>{{ domxref("document.createEntityReference") }} has been removed. It was never properly implemented and is not implemented in most other browsers.</li>
 <li><code>document.normalizeDocument</code> has been removed. Use {{ domxref("Node.normalize") }} instead.</li>
 <li>{{ domxref("DOMTokenList.item") }} now returns <code>undefined</code> if the <code>index</code> is out of bounds, previously it returned <code>null</code>.</li>
 <li><code>Node.getFeature</code> has been removed.</li>
 <li>The <code>HTMLInsElement</code> and <code>HTMLDelElement</code> interfaces have been removed, since the {{ HTMLElement("ins") }} and {{ HTMLElement("del") }} elements actually use the {{ domxref("HTMLModElement") }} interface.</li>
 <li>In a effort to conform to the upcoming <a class="external" href="http://www.w3.org/TR/dom/">DOM4</a> specification where {{ domxref("Attr") }} do not inherit from {{ domxref("Node") }} anymore (it did in DOM Core 1, 2 and 3), many {{ domxref("Node") }} properties and methods on the {{ domxref("Attr") }} interface are <a href="/en/DOM/Attr#Deprecated_properties_and_methods" title="En/DOM/Attr#Deprecated_properties_and_methods">now reporting warnings</a> as we work toward removing them in a later version.</li>
 <li>Added support for the {{ domxref("window.ondeviceorientation") }} and {{ domxref("window.ondevicemotion") }} properties on {{ domxref("window") }} objects.</li>
 <li>{{ domxref("window.resizeTo") }}, {{ domxref("window.resizeBy") }}, {{ domxref("window.moveTo") }} , and {{ domxref("window.moveBy") }} no longer apply to the main window.</li>
</ul>
<h3 id="JavaScript">JavaScript</h3>
<ul>
 <li>The <code><a href="/en/JavaScript/Reference/Global_Objects/Function/arity" title="en/JavaScript/Reference/Global_Objects/Function/arity">Function.arity</a></code> property has been removed; use <code><a href="/en/JavaScript/Reference/Global_Objects/Function/length" title="en/JavaScript/Reference/Global_Objects/Function/length">Function.length</a></code> instead.</li>
</ul>
<h3 id="WebSockets">WebSockets</h3>
<ul>
 <li>The <code>network.websocket.max-connections</code> preference is used to determine the maximum number of WebSocket connections that can be open at a time. The default value is 200.</li>
 <li>The underlying WebSocket protocol version 8 (as specified by <a class="external" href="http://tools.ietf.org/html/draft-ietf-hybi-thewebsocketprotocol-10" title="http://tools.ietf.org/html/draft-ietf-hybi-thewebsocketprotocol-10">IETF draft 10</a>) is used now instead of the version 7 protocol used by Firefox 6.</li>
 <li>The WebSocket API is now available on Firefox Mobile.</li>
</ul>
<h3 id="console_API">console API</h3>
<ul>
 <li>Message logged with <code>console.log</code> while the <a href="/en/Tools/Web_Console" title="Using the Web Console">web console</a> isn't open are still logged, although they aren't displayed when the web console is opened.</li>
</ul>
<div class="changelog">
 <h3 id="Web_timing">Web timing</h3>
 <ul>
  <li>Initial implementation of the <a href="/en/Navigation_timing">Navigation Timing</a> specification which provides data that can be used to measure the performance of a website.</li>
 </ul>
 <h3 id="XML">XML</h3>
 <ul>
  <li>In addition to the previously supported <code>text/xsl</code>, XSLT stylesheets can now use the official internet media (MIME) type <code>application/xslt+xml</code> (in the <a class="external" href="http://www.w3.org/TR/xml-stylesheet/" title="http://www.w3.org/TR/xml-stylesheet/">stylesheet processing instruction</a> or the <a class="external" href="http://tools.ietf.org/html/rfc5988">HTTP Link header field</a>).</li>
 </ul>
</div>
<h2 id="Changes_for_Mozilla_and_add-on_developers">Changes for Mozilla and add-on developers</h2>
<p>These changes affect add-on developers as well as developers working on or with Mozilla code itself. Add-on developers should see <a href="/en/Firefox/Updating_extensions_for_Firefox_7" title="en/Firefox/Updating extensions for Firefox 7">Updating extensions for Firefox 7</a> for additional information.</p>
<div class="note">
 <strong>Note:</strong> Firefox 7 requires that binary components be recompiled, as do all major releases of Firefox. See <a href="/En/Developer_Guide/Interface_Compatibility#Binary_Interfaces" title="En/Developer_Guide/Interface_Compatibility#Binary_Interfaces">Binary Interfaces</a> for details.</div>
<h3 id="JavaScript_code_modules">JavaScript code modules</h3>
<h4 id="FileUtils.jsm">FileUtils.jsm</h4>
<ul>
 <li>New method <code>openFileOutputStream()</code> opens a file output stream, the non-safe variant, for writing.</li>
</ul>
<h4 id="AddonManager.jsm">AddonManager.jsm</h4>
<ul>
 <li>The Add-on Manager has new methods for managing lists of add-ons that changed during applications startup: {{ AMInterface("AddonManager", "addStartupChange") }}, {{ AMInterface("AddonManager", "removeStartupChange") }}, and {{ AMInterface("AddonManager", "getStartupChanges") }}.</li>
</ul>
<h3 id="XUL">XUL</h3>
<ul>
 <li>{{ xulelem("tree") }} elements can now persist the state of disclosure triangles if the nodes referenced by {{ XULAttr("datasources") }} all have unique IDs specified by "id" attributes.</li>
 <li>{{ xulelem("panel") }} elements can now be configured to <a href="/en/XUL/PopupGuide/Panels#Letting_panels_be_dragged_by_grabbing_the_background" title="en/XUL/PopupGuide/Panels#Letting_panels_be_dragged_by_grabbing_the_background">let the user drag them by clicking anywhere on their background</a> by using the new {{ XULAttr("backdrag") }} attribute.</li>
</ul>
<h3 id="XPCOM">XPCOM</h3>
<ul>
 <li>The new <a href="/en/Components.utils.schedulePreciseGC" title="en/Components.utils.schedulePreciseGC"><code>Components.utils.schedulePreciseGC()</code></a> method lets you schedule a thorough garbage collection cycle to occur at some point in the future when no JavaScript code is executing; a callback is executed once collection is complete.</li>
 <li>The <a href="/en/Components.utils.unload" title="Components.utils.unload"><code>Components.utils.unload()</code></a> method lets you unload JavaScript code modules previously loaded by calling <a href="/en/Components.utils.load" title="en/Components.utils.load"><code>Components.utils.load()</code></a>.</li>
</ul>
<h3 id="Memory_reporters">Memory reporters</h3>
<p>Support has been added for multi-reporters; that is, memory reporters that gather data on request and call a callback for each generated result. See {{ interface("nsIMemoryMultiReporter") }} and {{ interface("nsIMemoryMultiReporterCallback") }} for the relevant interfaces, as well as the {{ ifmethod("nsIMemoryReporterManager", "registerMultiReporter") }} and {{ ifmethod("nsIMemoryReporterManager", "unregisterMultiReporter") }} methods.</p>
<h3 id="User_experience_changes">User experience changes</h3>
<ul>
 <li>Extension options can now be <a href="/en/Extensions/Inline_Options" title="en/Extensions/Inline_Options">displayed inside the Add-on Manager</a> for both restartless and traditional extensions.</li>
 <li>The destination of downloads is now remembered on a site-by-site basis. This data can be accessed using <a href="/en/JavaScript_code_modules/DownloadLastDir.jsm" title="en/JavaScript_code_modules/DownloadLastDir.jsm">DownloadLastDir.jsm</a>.</li>
</ul>
<h3 id="Changes_to_the_build_system">Changes to the build system</h3>
<ul>
 <li>The ActiveX embedding API is no longer built and support has been removed from the build system. Supporting interfaces have also been removed; see {{ anch("Removed interfaces") }}.</li>
 <li>You should no longer specify <code>-Zc:wchar_t-</code> when building on Windows. See the <a href="/En/Developer_Guide/Build_Instructions#Build_and_install" title="En/Developer_Guide/Build_Instructions#Build_and_install">updated Build documentation</a> for details.</li>
</ul>
<h3 id="Interface_changes">Interface changes</h3>
<ul>
 <li>{{ interface("nsISocketTransport") }} now offers a new connection flag: <code>DISABLE_IPV6</code>; this causes a socket to only attempt to connect to IPv4 addresses, ignoring any available IPv6 addresses. In addition, {{ interface("nsIDNSService") }} now offers a new resolve flag: <code>RESOLVE_DISABLE_IPV6</code>; this causes domain name resolution to only consider IPv4 hosts, ignoring any available IPv6 addresses. These changes are used to implement the <a class="external" href="http://tools.ietf.org/html/draft-wing-http-new-tech-00">"happy eyeballs" strategy</a> for improving response time when attempting to connect on hosts that support both IPv4 and IPv6 (especially those that have broken IPv6 connectivity).</li>
 <li>{{ interface("inIDOMUtils") }} has two new methods, {{ ifmethod("inIDOMUtils","getChildrenForNode") }} which returns a list of child nodes of a node and {{ ifmethod("inIDOMUtils","getUsedFontFaces") }} which returns a list of font faces used in a range.</li>
 <li>The <code>nsIMarkupDocumentViewer_MOZILLA_2_0_BRANCH</code> interface has been merged into the {{ interface("nsIMarkupDocumentViewer") }} interface.</li>
 <li>The <code>nsIDOMWindow2</code> interface has been merged into the {{ interface("nsIDOMWindow") }} interface.</li>
 <li>The <code>nsIDOMWindow_2_0_BRANCH</code> interface has been merged into the {{ interface("nsIDOMWindowInternal") }} interface.</li>
 <li>{{ interface("nsINavHistoryObserver") }} methods with URI parameters now require a GUID as well.</li>
 <li>The <code>nsISHistory_2_0_BRANCH</code> interface has been merged into the {{ interface("nsISHistory") }} interface.</li>
 <li>{{ interface("nsITelemetry") }} has a new method, {{ ifmethod("nsITelemetry","getHistogramById") }} which returns a histogram by its ID, and a new attribute, <code>canRecord</code> which when set to <code>false</code> disables recording of telemetry statistics. Telemetry statistics are no longer recorded when in Private Browsing Mode. (see {{ bug("661574") }} and {{ bug("661573") }})<br>
  Telemetry histograms defined with {{ ifmethod("nsITelemetry","newHistogram") }} will not be reported in the telemetry ping.</li>
 <li>The {{ interface("nsIMemoryReporter") }} interface has been substantially changed; if you use it, you will need to make some adjustments to your code.</li>
 <li>{{ interface("nsIXMLHttpRequest") }}, headers set by {{ ifmethod("nsIXMLHttpRequest","setRequestHeader") }} are sent with the request when following a redirect. Previously these headers would not be sent.</li>
 <li>{{ interface("nsIDocShell") }} has a new <code>allowWindowControl</code> attribute. If <code>true</code>, the docshell's content is allowed to control the window (that is, to move or resize the window).</li>
 <li>The <code>nsIThreadInternal2</code> interface has been merged into the {{ interface("nsIThreadInternal") }} interface.</li>
</ul>
<h4 id="New_interfaces">New interfaces</h4>
<dl>
 <dt>
  {{ interface("nsIDOMFontFace") }}</dt>
 <dd>
  Describes a single font face.</dd>
 <dt>
  {{ interface("nsIDOMFontFaceList") }}</dt>
 <dd>
  Describes a list of font faces, each represented by {{ interface("nsIDOMFontFace") }}.</dd>
</dl>
<h4 id="Removed_interfaces">Removed interfaces</h4>
<p>The following interfaces were implementation details that are no longer needed:</p>
<ul>
 <li><code>nsIDOM3Attr</code></li>
 <li><code>nsIDOM3Node</code></li>
 <li><code>nsIDOM3TypeInfo</code></li>
 <li><code>nsIDOM3Text</code></li>
 <li><code>nsIDOMDocumentStyle</code></li>
 <li><code>nsIDOMNSDocument</code></li>
 <li><code>nsIDOMNSFeatureFactory</code></li>
 <li>{{ interface("nsIDOMNSHTMLDocument") }}</li>
 <li><code>nsIDOMNSHTMLFormElement</code></li>
 <li><code>nsIDOMNSHTMLHRElement</code></li>
 <li><code>nsIDOMNSHTMLTextAreaElement</code></li>
</ul>
<p>The following interfaces were removed as part of the removal of the ActiveX embedding API:</p>
<ul>
 <li><code>DITestScriptHelper</code></li>
 <li><code>DWebBrowserEvents</code></li>
 <li><code>DWebBrowserEvents2</code></li>
 <li>{{ interface("IDispatch") }}</li>
 <li><code>IMozControlBridge</code></li>
 <li><code>IMozPluginHostCtrl</code></li>
 <li><code>IWebBrowser</code></li>
 <li><code>IWebBrowser2</code></li>
 <li><code>IWebBrowserApp</code></li>
 <li><code>IXMLDocument</code></li>
 <li><code>IXMLElement</code></li>
 <li><code>IXMLElementCollection</code></li>
 <li><code>IXMLError</code></li>
 <li><code>nsIActiveXSecurityPolicy</code></li>
 <li>{{ interface("nsIDispatchSupport") }}</li>
 <li><code>nsIMozAxPlugin</code></li>
 <li><code>nsIScriptEventHandler</code></li>
 <li><code>nsIScriptEventManager</code></li>
</ul>
<h3 id="Other_Changes">Other Changes</h3>
<ul>
 <li>The structure of the library window (<code>places.xul</code>) <a class="link-https" href="https://bugzilla.mozilla.org/show_bug.cgi?id=588027">has been cleaned up</a>. This <a class="link-https" href="https://bugzilla.mozilla.org/show_bug.cgi?id=677417">may break extensions</a> and themes.</li>
 <li>The look of the print preview window <a class="link-https" href="https://bugzilla.mozilla.org/show_bug.cgi?id=663028">has been modernized</a> and theme authors are encouraged to style it using the CSS pseudo-elements {{ cssxref("::-moz-page") }}, {{ cssxref("::-moz-page-sequence") }} and {{ cssxref("::-moz-scrolled-page-sequence") }}.</li>
</ul>
<h2 id="See_also">See also</h2>
<div>
 {{Firefox_for_developers('6')}}</div>