Proposal: tabs.Tab should include the documentId.

[newRoland]

Context

The documentId has use cases throughout the WebExtensions APIs, and more is to come. However, the only ways to retrieve it seems to be by pinging a content script or using the WebNavigation permission (getFrame, onCommitted).

The WebNavigation permission has a permissions warning that many extension publishers will like to avoid. It's also safer for the user if the extension doesn't need it. The developer might also not have a content script available for pinging.

Proposal

The Tab object already includes information on the tab's main frame like URL, pendingURL, favicon, etc. I propose also including the documentId and pendingDocumentId. That way it can be retrieved through tabs.get or tabs.query.

[newRoland]

Turns out you can also retrieve the documentId from pinging a content script and getting a reply. OnMessage sender includes documentId. The proposal is still useful, but it's no longer necessary for me.

[fregante]

This would still be useful and make a lot of sense. Having to ping the content script means you also need the scripting permission, whereas accessing this documentId probably wouldn't even need tabs

[newRoland]

I can't think about specific examples it would be needed. It's worth it for the convenience alone, but I don't think they will implement the proposal without a stronger justification.

[fregante]

If you reopen they will decide. If not I'll reopen the issue myself

[newRoland]

A better proposal might be to alias getFrame, and getAllFrames, so it's accessible from both webNavigation and tabs.