Make Privly a restartless extension

[ehsan]

Starting from Firefox 4, Firefox supports extensions which can be installed/removed without restarting.

This mainly boils down to ensuring that the dynamic changes to the browser window happen on extension startup, and the extension is responsible for reverting those changes at shutdown.

I have started to make Privly restartless in this branch: https://github.com/ehsan/privly-firefox/tree/restartless

The major todo item is hooking up the Options dialog, but the rest of the basics should work fine. I didn't have a lot of time to hack on this today, so consider this branch as the skeleton. In particular I have not performed any testing as I don't have a bit.ly account yet (I've submitted a request for an invitation!).

Please feel free to pull in this branch, and build on top of it, or give me access to priv.ly so that I can test this and prepare it for a pull request myself.

[smcgregor]

@ehsan Balaji is cleaning up observers.js and will comment on it later tonight. Refactoring it into a module would be great.

It looks like your gmail may have gotten shut down (!), do you have an email address you want an invite sent to?

[ehsan]

Hmm, I thought that my gmail problem has been fixed! Could you please use my first name at mozilla.com? Also, I'd appreciate if you can forward the gmail bounce message to that address as well! :-)

[smcgregor]

I sent the invitation to your Mozilla email. Please let me know if you have any problems.

They reactivated your gmail already? I read about it being shut down on your blog, so I didn't send an invite there. I can issue another invite to the gmail if you want me to.

[ehsan]

Ah, yes, the account is reactivated. But thanks, the invitation you already sent should be enough.

[smcgregor]

Since we are prepping to add a compiled library to the extension, now is the time to decide whether we are going to make the extension restartless. I am not convinced that making the extension restartless is worth the tradeoffs. However, the potential benefits of Jetpack could tip the balance. My notes are below, but the conclusion is open to discussion. I would certainly revisit the conclusion if someone at Mozilla made a recommendation ;)

Just making the extension Restartless

Pros:

• Users don't have to restart the extension
• It would be easier to adopt Jetpack later

Cons:

• The number of hacks involved
• The dominant XUL design pattern uses overlays, which are not supported by restartless add-ons without hackery
• Most existing extension development guides assume the extension needs a restart, meaning we would need to educate potential devs on the differences in our architecture
• It will take time to refactor/debug and we are already spread thin

Moving to Jetpack

Pros:

• We need a testing framework for the extension and Jetpack has it built in (yay!)
• Restartless extensions have better user experience
• It looks like Mozilla wants to emphasize Jetpack in the long run

Cons:

• Mozilla has no plans to deprecate XUL based add-ons because the vast majority of add-ons are XUL based.
• Most developers know XUL based add-ons better than Jetpack add-ons
• Jetpack is not mature

Conclusion

For me, this comes down to the direction Mozilla is moving with their extension support. If Jetpack extensions will be increasingly dominant, we should move to Jetpack at our earliest convenience. Otherwise, we should probably stick with a restart-dependent add-on.

[smcgregor]

Subsumed by #38.