1450386 - [WebExt feature request]: set favIconUrl via tabs.update

Status: RESOLVED WONTFIX

(WebExtensions :: Frontend, enhancement)

Description

[Niklas Gollenstede]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:60.0) Gecko/20100101 Firefox/60.0
Build ID: 20180322152034

Steps to reproduce:

It would be useful if WebExtesions could change the favIconUrl (and thus the displayed icon) of tabs.
AFAIK the actually displayed icon is not reported to the page, so there won't be a problem there.
For loaded pages, the icon can effectively be changed by setting the corresponding meta tags in the page, but for unloaded pages that is not possible.
Setting the favicon could be prevented for pages the extension doesn't has host permissions for. (including privileged pages).

The lack of this API prevents me from working around the problem I reported in bug #1450382, but I am sure there would be other interesting applications for this API as well.


Actual results:

WebExtensions can't change pages favicons when the page isn't loaded.


Expected results:

`browser.tabs.update()` should accept a `favIconUrl` property in its update parameter.

Comment 1

[Caitlin Neiman [:caitmuenster]]

Hi Niklas, this bug has been added to the agenda for the WebExtensions APIs triage on July 10, 2018. Would you be able to join us? 

Here’s a quick overview of what to expect at the triage: 

* We normally spend 5 minutes per bug
* The more information in the bug, the better
* The goal of the triage is to give a general thumbs up or thumbs down on a proposal; we won't be going deep into implementation details

Relevant Links: 

* Wiki for the meeting: https://wiki.mozilla.org/WebExtensions/Triage#Next_Meeting
* Meeting agenda: https://docs.google.com/document/d/1Y_oYPldTT_kQOOouyJbC-8y3ASIizScLKFRhQfsDQWI/edit#heading=h.mr8julfcusgv
* Vision doc for WebExtensions: https://wiki.mozilla.org/WebExtensions/Vision

Comment 2

[Mike Conca [:mconca]]

This was discussed at the meeting.  Outcome:

Request denied. Working around a bug in Firefox (bug 1450382) is not sufficient reason to approve a new API. That said, this request is intriguing enough to be considered part of upcoming work on themes and how to handle the styling of individual tabs.

Comment 3

[Wolfgang Faust]

Non-bug-workaround use case: Changing the favicon for sites that don't have one. There are at least two Firefox extensions that do this, my own IdentFavIcon Quantum as well as Favioli. Currently the way we do this is with a user script to inject a <link> tag, but this feels very hacky and a proper API to do this would be greatly appreciated.

Comment 4

[Mike Conca [:mconca]]

While acknowledging the use case in comment #3, I'm closing this per the design decision outcome noted in comment #2.