Firefox 19 was released on February 19, 2013. This article lists key changes that are useful not only for web developers, but also Firefox and Gecko developers as well as add-on developers.
Want to help document Firefox 19? See the list of bugs that need to be written about and pitch in!
Changes for Web developers
Setobjects have changed from having a
size()method to a
sizeproperty (bug 807001)
Setobjects also have a clear() method now. (bug 805003)
- Support for the viewport-relative
vmax, has landed (bug 503720)
- CSS Flexbox has been unprefixed, but remains disabled by default (bug 801098).
-moz-initialvalue has been unprefixed (bug 806068).
-moz-initialwill be kept for a while as an alias; however, authors are strongly encouraged to switch over to
- The CSS
text-transformproperty now supports the
full-widthkeyword, which allows a more seamless inclusion of Latin characters in text using ideographic fixed-width characters, like Chinese or Japanese (bug 774560).
- The CSS
page-break-insidehas been implemented (bug 685012).
- The CSS
calc()function can now be used on
- The CSS
@pageat-rule is now supported (bug 115199). Note that the pseudo-classes
:leftare not yet implemented.
:-moz-placeholderpseudo-class is replaced by the
::-moz-placeholderpseudo-element (bug 737786).
element.getElementsByTagNamemethod will now return
mozLastModifiedDateproperty has been implemented. (bug 793955)
FilelastModifiedDate property returns the current date, when the date of the last modification is unknown. (bug 793459
isPointInStrokemethod has been implemented (bug 803124).
toBlobmethod has been implemented (bug 648610).
document.implementation.hasFeature()methods have been changed to always return
- When calling
nullwill now be stringified and works like
TextEncoderinterfaces have been updated to match the latest spec (bug 801487).
Changes for add-on and Mozilla developers
Note: A key change in Firefox 19 is that
nsresult is now strongly typed. This will help make it easier to detect bugs that are caused by mishandling of return values, but may cause existing code to break if it's making incorrect assumptions in this regard.
getBrowserSelection()now returns the selected text in a text input field. As a result,
truewhen the user selects text in a text input field that is not a password field. (bug 565717)
Dict()now takes a JSON String.
Dict.toJSON()was added, and it returns a JSON String. (bug 727967)
The parameter (aObserver) of
addObserver()method changes from
imgINotificationObserveris not scriptable, so you need to use
- Firefox 18 for developers
- Firefox 17 for developers
- Firefox 16 for developers
- Firefox 15 for developers
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- Firefox 12 for developers
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- Firefox 3.6 for developers
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- Firefox 1.5 for developers