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Firefox 69 release notes for developers

files/en-us/mozilla/firefox/releases/69/index.md

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This article provides information about the changes in Firefox 69 that will affect developers. Firefox 69 was released on September 3, 2019.

Changes for web developers

Developer tools

Debugger

  • Event Listener Breakpoints let you diagnose which code a page executes in response to browser events. You can pick specific types, such as click or keydown, or whole categories of events, like all mouse input events. (Firefox bug 1526082).
  • Scripts shown in the debugger's source list pane can now be saved via the Download file context menu option (Firefox bug 888161).
  • In the debugger's source list pane, loaded extensions are listed with their name, rather than just their {{Glossary("UUID")}} (Firefox bug 1486416), making it much easier to find the extension code you want to debug.
  • The debugger now loads significantly faster via lazy-loading scripts (Firefox bug 1527488).

Console

Network

Inspector

  • When you hover over an element in the Page Inspector, the infobar that appears now includes the fact that an element is a flex container, or flex item (Firefox bug 1521188).
  • When inspecting a page containing a grid with a subgrid, the parent grid's overlay lines are displayed whenever the subgrid's lines are displayed; if the parent grid's overlay checkbox is unselected, then its lines are translucent (Firefox bug 1550519).

Remote debugging

  • For our mobile web developers, we have migrated remote debugging from the old WebIDE into a re-designed about:debugging, making the experience of debugging GeckoView on remote devices via USB much better (Firefox bug 1462208).

General

HTML

  • In order to align more closely to the specification, the text track associated with a {{HTMLElement("track")}} element no longer loads the WebVTT file containing the text cues if the element is created in its default disabled {{domxref("TextTrack.mode", "mode")}}. To access or manipulate the cues when the mode is disabled, change the mode to either started or hidden; this will trigger loading of the WebVTT data (Firefox bug 1550633).

Removals

  • The HTML <keygen> element has been removed from Firefox. It was deprecated some time ago, and its purpose has generally been supplanted by other technologies (Firefox bug 1315460).

CSS

  • We implemented the break-spaces value of the {{cssxref("white-space")}} property (Firefox bug 1351432).
  • The SVG geometry attributes (such as {{SVGAttr("width")}} and {{SVGAttr("height")}}) can now also be defined as CSS properties (Firefox bug 1383650).
  • The {{cssxref("::cue")}} selector — used to style the captions ("cues") displayed by WebVTT — now enforces the limitations on which CSS properties may be used within cues, as per the specification (Firefox bug 1321488).
  • We've restricted the properties that may apply to {{cssxref("::marker")}} as per the specification (Firefox bug 1552578)
  • The {{cssxref("overflow-block")}} and {{cssxref("overflow-inline")}} properties have been implemented (Firefox bug 1470695).
  • We added the ability to test for support of a selector when using CSS Feature Queries ({{cssxref("@supports")}}), with the selector() method (Firefox bug 1513643).
  • The {{cssxref("user-select")}} property — which specifies whether or not the user is able to select text in the affected element — has been unprefixed (Firefox bug 1492739).
  • We implemented local-specific casing behavior for Lithuanian (Firefox bug 1322992), as seen in this example.
  • We've implemented the {{cssxref("line-break")}} property of CSS Text (Firefox bug 1011369 and Firefox bug 1531715).
  • The {{cssxref("contain")}} property — which allows developers to define that an element and its contents are mostly independent of the rest of the DOM tree — got implemented Firefox bug 1487493.

SVG

  • We've added support for gzip-compressed SVG-in-OpenType (Firefox bug 1359240).
  • The {{domxref("SVGGeometryElement.isPointInFill()")}} and {{domxref("SVGGeometryElement.isPointInStroke()")}} methods have been implemented (Firefox bug 1325319).

JavaScript

HTTP

  • The HTTP headers {{HTTPHeader("Access-Control-Expose-Headers")}}, {{HTTPHeader("Access-Control-Allow-Methods")}}, and {{HTTPHeader("Access-Control-Allow-Headers")}} now accept a wildcard value * for requests without credentials (Firefox bug 1309358). This change has also been uplifted to Firefox 68 ESR.

APIs

New APIs

DOM

  • The {{domxref("DOMMatrix")}}, {{domxref("DOMPoint")}}, and related objects are now supported in workers (Firefox bug 1420580).
  • The pageX and pageY properties have been moved from {{domxref("UIEvent")}} to {{domxref("MouseEvent")}}, for better spec compliance (Firefox bug 1178763). These properties are no longer exposed to the {{domxref("CompositionEvent")}}, {{domxref("FocusEvent")}}, {{domxref("InputEvent")}}, {{domxref("KeyboardEvent")}}, and {{domxref("TouchEvent")}} interfaces, which all inherit from UIEvent.
  • The {{domxref("Blob.text()")}}, {{domxref("Blob.arrayBuffer()")}}, and {{domxref("Blob.stream()")}} methods are now implemented (Firefox bug 1557121).
  • DOMMatrixReadOnly.fromMatrix() has been implemented (Firefox bug 1560462).
  • We now support the six-parameter version of the {{domxref("DOMMatrixReadOnly.scale()")}} method (Firefox bug 1397945).
  • The arguments for {{domxref("DOMMatrixReadOnly.translate()")}}, {{domxref("DOMMatrixReadOnly.skewX()")}}, and {{domxref("DOMMatrixReadOnly.skewY()")}} are now all optional, as per spec (Firefox bug 1397949).
  • The {{domxref("Navigator.userAgent")}}, {{domxref("Navigator.platform")}}, and {{domxref("Navigator.oscpu")}} properties no longer reveal whether a user is running 32-bit Firefox on a 64-bit OS (Firefox bug 1559747). They now say Linux x86_64 instead of Linux i686 on x86_64, and Win64 instead of WOW64.
  • The remaining methods of {{domxref("HTMLDocument")}} have been moved to {{domxref("Document")}}. This should have no appreciable impact on your work in most cases. In particular, the {{domxref("document.close", "close()")}}, {{domxref("document.open", "open()")}}, and {{domxref("document.write", "write()")}} methods have been moved. So have the various editor related methods, including {{domxref("document.execCommand", "execCommand()")}} as well as various properties (Firefox bug 1549560).
  • We have implemented {{domxref("AbstractRange")}} and {{domxref("StaticRange")}} (Firefox bug 1444847).

Media, Web Audio, and WebRTC

  • For improved user security, and in-keeping with the latest versions of the Media Capture and Streams specification, the {{domxref("navigator.mediaDevices")}} property is no longer present if the context is insecure. To use {{domxref("MediaDevices.getUserMedia", "getUserMedia()")}}, {{domxref("MediaDevices.getDisplayMedia", "getDisplayMedia()")}}, {{domxref("MediaDevices.enumerateDevices", "enumerateDevices()")}}, and so forth, be sure your content is loaded using {{Glossary("HTTPS")}} (Firefox bug 1528031).
  • The Web Audio API's {{domxref("AudioParam.value")}} property now returns the actual value of the property at the current time, taking into account all scheduled or graduated value changes. Previously, Firefox only returned the most recent explicitly-set value (as through using the value setter) (Firefox bug 893020).
  • We've updated {{domxref("MediaStreamAudioSourceNode")}} to use the new, lexicographical, ordering for tracks. Previously, track ordering was up to the individual browser, and could even change arbitrarily. In addition, attempting to create a MediaStreamAudioSourceNode using a stream that has no audio tracks now throws an InvalidStateError exception (Firefox bug 1553215).
  • The {{domxref("MediaTrackSettings.facingMode", "facingMode")}}, {{domxref("MediaTrackSettings.deviceId", "deviceId")}}, and {{domxref("MediaTrackSettings.groupId", "groupId")}} settings are now included as members of the {{domxref("MediaTrackSettings")}} object returned by calls to {{domxref("MediaStreamTrack.getSettings()")}} (Firefox bug 1537986).

Removals

WebDriver conformance (Marionette)

Other

  • Marionette now dynamically handles the opening and closing of modal dialogs and user prompts (Firefox bug 1477977), which also means that multiple open prompts will be handled (Firefox bug 1487358).
  • Tracking protection and DOM push features are now disabled by default to avoid the removal of parts of the DOM, and extra notifications (Firefox bug 1542244).
  • Automatic unloading of background tabs if Firefox runs into a low memory condition is now disabled — this badly interacts with automation when switching between tabs (Firefox bug 1553748).

Changes for add-on developers

API changes

Other changes

See also