Add-on Compatibility for Firefox 27

Jan 21 2014

Firefox 27 will be released on February 4th. This release cycle is slightly longer due to the holidays. Here’s the list of changes that went into this version that can affect add-on compatibility. There is more information available in Firefox 27 for Developers, so you should read that too.

General

Do away with downloads-indicator. The downloads-button and downloads-indicator nodes were serving the same purpose, so the former was kept and the latter was removed. If you’re using downloads-indicator in your JS or CSS code, make sure to replace it with downloads-button.
[OS.File] Inconsistent cross-platform behavior due to O_APPEND. If you’re using the OS.File library, opening files on non-Windows systems would have opened them with the append option on by default, while not so on Windows. This change makes all file open calls not append by default.
Findbar for Stylish editor is broken. If your extension includes a view which uses a findbar, it may be broken on 27. The details about this change can be found on bug 939381.
Remove -moz-rgba() and -moz-hsla(). The unprefixed CSS functions should be used instead.

XPCOM

Stop exporting JS symbols in Firefox. JSAPI is no longer available to extensions, which should only really be a problem for very specific binary add-ons. There are better ways to run JS in your extension anyway.

New!

Need a way to create invisible, permanent docshell. If you’re currently using the hidden DOM window or another hack to keep a hidden DOM structure, you might want to give this one a look. With createWindowlessBrowser, you can create a hidden content or chrome window.
Add log4moz.js to toolkit as Log.jsm. log4moz is a very useful logging tool based on its popular Java counterpart, log4j. It has existed in various forms along the years, but now it is very easily accessible using Log.jsm.
Expose DOM URL to js modules. You can now access the URL global constructor from a JSM.
Command line option -jsconsole should open the Browser Console. Like it used to be possible with the old Error Console, now you can invoke the Browser Console from the command line.
[OS.File] Add a function to recursively remove directories.
Option to deobfuscate JavaScript in the debugger.

Please let me know in the comments if there’s anything missing or incorrect on these lists. If your add-on breaks on Firefox 27, I’d like to know.

The automatic compatibility validation and upgrade for add-ons on AMO will happen very soon, so keep an eye on your email if you have an add-on listed on our site with its compatibility set to Firefox 26.

8 responses

You Screwed Up Bigtime wrote on February 6, 2014 at 12:05 pm:

27 didn’t just disable all my add-ins, it removed them. Seriously, what is wrong with you people, I now have no extensions.
Brandy wrote on February 7, 2014 at 1:56 pm:

Why is it the with this new update evey time i click on firefox icon it pops up add-on compatibility update everything i open firefox, this is very very anonoying since i have to cancel it just to get to my homepage….. there has to be a way to disable this very annoying window, until this is fixed or i can go back to 26.0 ill use IE !!!!! please fix since I really hate IE !!!
UV wrote on February 10, 2014 at 6:26 pm:

This update is seriously annoying, you have taken a great product and turned it into somthing worthy of getting people to pull their hair out. Please fix this ridiculous addon compatibility check everytime firefox loads.

A check is only required the 1st time FF27 runs and subsequently if someone installs a new addon .. not every time the browser starts.
Luke wrote on February 18, 2014 at 7:30 am:

The extension update check only runs once when it upgrades, and you can click “cancel” and it skips that step.

The new update is nice, but there’s no mention here that changes in the devtools may require rewriting. I had to switch from dblclick to mouseup catching, since something was preventing bubbling of the dblclick event up to the window:
https://github.com/programmin1/DevTools-Tweaks/commit/73c3147537f2f54c551c5a426e55806bea67a1b0

but that’s a fairly rare use case though I’d imagine.
Tricia wrote on February 18, 2014 at 3:11 pm:

I AM BEYOND DISGUSTED!!! For 2-3 months now, I have tried every suggestion available to GET RID OF THE COMPATIBILITY CHECK!!! and nothing works! This is such a waste of my time and beyond annoying! nothing ever changes and yet I must put up with this ridiculous ‘check’ every single time I start FF – I get the pop-up window that Firefox is checking add-on compatibility! Since I cannot seem to get this to stop, I will start using only GOOGLE CHROME! Thanks for ruining my day, again!
buttduck wrote on February 22, 2014 at 5:02 pm:

Well, more people passing the buck, answer the questions people ! … You techies cant see the wood for the trees. You geeks need more daylight …. and me, i need less caffine ! …. Firefox – get rid of Compatibilty Check, it SUCKS … simple see ! = Everone will then be HAPPY and a better world for ALL — Nuff Said !
Mike wrote on March 19, 2014 at 2:28 am:

Compatibility check drove me mad, so am now using IE and Chrome.
Why can’t you listen to the people who support your browser!!!
Will Jones wrote on May 9, 2014 at 5:46 am:

The Add-on compatibility check is a waste of space and the fact that Mozilla refuses to allow users to turn it off, suggests to me at least, that it is some sort of spyware designed to let Mozilla inflict us with even more bloody adverts. I’ve just downloaded the latest Internet Explorer and after writing this, will be removing Firefox and installing IE

FIREFOX IS CHRONIC. INSTALL IT AT YOUR PERIL.