Update: Thanks to Ken Saunders for the suggestion to use 7-Zip instead of WinRAR. Using 7-Zip greatly simplifies this process.
I downloaded and installed Firefox 3.7a6pe today (more on this in another post). Everything was going fairly well until I started to move my extensions over from Firefox 3.6 profile. I was going to start with Nightly Tester Tools, but found out it is only compatible up to Firefox 3.7a5. Simple enough, I’ll just apply the Overriding Add-ons Compatibility Check Tweak I wrote earlier this year. That doesn’t seem to work with Firefox 3.7 or it may be related to the ‘problems with the new add-ons manager’ in Firefox 3.7 that people were mentioning in the Firefox Builds forum.
Last year I helped a family member get a theme they had been using to work with Firefox 3.5 and earlier this year with 3.6. This involves hacking the add-on (works with extension or theme) and modifying one line in the install.rdf file to make the add-on compatible with the newer version of Firefox.
WARNING! Forcing an add-on to work can cause unwanted behaviours including browser crash upon start-up. Familiarize yourself on how to use Firefox Safe-Mode.
Before you start you will need a file compression/archiving utility that supports .JAR files. 7-Zip works very well. Also I suggest using Notepad++ as it is a much better file editor than the traditional Notepad/Wordpad (DO NOT use a Word Processor such as MS Word). To associate Notepad++ as the editor for 7-Zip, in 7-Zip go to Tools >> Options.. > Editor and locate where Notepad++ is installed. Once you have these two applications installed and setup then you are ready to start:
- Download the add-on. When on the addons.mozilla.org page right-click on the Add to Firefox button and choose Save Link As…
- Locate the saved file. Right-click and from the context menu select 7-Zip >> Open Archive
- Locate the install.rdf file within the 7-Zip interface right-click and select Edit this will open the default editor connected to 7-Zip.
- Edit the install.rdf file. In your editor activate the find function (CTRL+F) and in the find box enter maxVersion (note: some add-ons may use the same install.rdf file for multiple applications be sure to make sure your editing the Firefox version).
- To the right of this ‘tag’ you are going to see a number. This reflects the latest version of Firefox this add-on supports. You will want to change this to the next highest version of Firefox:
- Using Firefox 3.5 change this number to 3.6
- Using Firefox 3.6 change this number to 3.7
- Using Firefox 3.7 change this number to 4.1
- Using Firefox 4.0 change this number to 4.1
- Save the file. Once you return to 7-Zip it should prompt you the file has been modified. Click OK to update the archive.
- Drag the add-on file from the Explorer window into Firefox to install as normal
Notepad++ is great, but I use 7-Zip. I have it open XPI’s by default and with 7-Zip installed, I just open the XPI with a double click, again on the install.rdf, change version numbers > save > close, follow the 7-Zip prompts and it’s done. For JAR’s I right click on the file > 7-Zip > Open archive and then on to the install.rdf.
@Ken I had forgotten about 7-Zip, think I’ve used at work. Thanks for the info.
The xpi file is only a zip package and not a jar file like you said in that post early.
I’ve been desperate to get a compact theme in 4.0 (I hate all the wasted space and scrolling the default theme requires). Littlefox is supposed to work, but I just can’t get it to install. I have extensions.checkCompatibility.4.0 set to false. I’m running ubuntu, so I modified the steps a bit: Archive Manager instead of 7-zip, and gedit instead of Notepad. The install.rdf had 4.0b2pre as the max version, which I changed to 4.1. I also set the .jar file to executable.
Now comes the bit I’m not clear about. When I drag the downloaded .jar file into the add-ons window in FF4, it says “downloaded” in the status ellipse off to the right. After pushing the install button, it instantly returns “error installing” same as when I try it the usual way from the mozilla addons page. Is that because I’m doing something wrong? Because Littlefox is not a good test case for this? Because it won’t work in linux? Or because this is still a bug in 4.0?
After the latest update to Minefield (as of Jul 5), suddenly I could install Littlefox and a couple of other things as well. They’re making progress!