Setting browser preferences when using Webextensions API

I am porting a “legacy” firefox addon to use webextension API. This addon modifies a global preference (signon.rememberSignons) to stop the browser password manager.

  • The “component” object does not expose the class property anymore.
  • I can’t use the preference service available in JDK

=>Is there any other solution than wait for the chrome object to expose a “privacy” property to appear (not available in FF46)?

thanks in advance !

WebExtensions won’t support access to arbitrary preferences. At the moment it doesn’t support access to the password manager either, though it may in the future.

Why is your extension disabling the password manager? Does it replace it with something else?

Hello Jorge, yes our extension is a password management extension and we want the standard FF behavior to be deactivated once our user has signed in our extension. This is basically to avoid interferences between our stuff and the FF password manager to not confuse the user.

thank you.

WebExtensions won’t support access to arbitrary preferences.

Do you have a source for that? If that’s the case an extension of mine is not portable to WebExtensions.

Access to preferences certainly seems to be in demand:

If a decision has been made regarding that API it should be communicated to the Uservoice users and Add-on developers.

[quote=“slosd, post:4, topic:8561”]
Do you have a source for that?[/quote]
I think everyone working on WebExtensions would agree with that, but I don’t know if it’s written down anywhere. It’s certainly not part of any plans for the WebExtensions API.

What does your extension do?

It provides an about:preferences-like UI for preferences which are not exposed there. Changing preferences is core to this extension.

Yeah, in that case the default API won’t work for you. There is an alternative, which is the native.js initiative, which is meant to allow add-ons to extend the WebExtensions API on a case-by-case basis. This is still very early in development, though.

Ok, thanks. I’ll be following the native.js bugs.

Jorge, thanks,
Is there a roadmap somewhere where we can check what are the expected dates/FF releases to enhance Webextensions & get an idea of the status of native.js ?

rgds, JM

The progress of the API can be seen at If you want to get more involved and get more concrete answers I suggest you use the contact info provided in the wiki page.