Brave-browser: Support for custom filter lists in Shields

[fmarier]

Description

Some popular adblocking extensions help users create filter lists to supplement the default ones. This can for example allow someone to hide parts of a website that are not deemed useful or desirable but that would otherwise be out of scope for EasyList/EasyPrivacy.

This is an advanced use case for sure, and we should focus on shipping the best default-on adblocker, but I thought I'd mention it since it might allow some users to avoid installing an additional extension and have everything they need built-in.

Designs

Add functionality to subscribe to filter lists via URL on brave://adblock

Insert the following designs below “Additional Filters” and above “Custom Filters”:

After the user clicks on "Add filter list via URL", a form field appears with "Submit" and "Cancel":

Built-in error validation for the field specifies entry must start with https://

Submitting the filter list URL will add the filter list to a table with a toggle to enable/disable and available actions:

• Update now
• View website
• View source
• Unsubscribe

If the user enters a filter list that is invalid or unavailable, the table entry shows the filter as Download failure with no toggle available:

Assets

Figma: https://www.figma.com/file/tLXWGCpNoiJxDZDdpfordj/Desktop-Settings?node-id=49%3A2359

[rebron]

cc: @pes10k @ryanbr Is this a dupe?

[pes10k]

No, this is different. Currently Brave users can add additional rules in the text box on brave://adblock (soon to be brave://shields/filter-rules I think). Whats being asked for here, I believe, is the ability to subscribe to new lists, by URL.

[ryanbr]

Another way could be added, via ahref abp:subscribe? to streamline custom filter additions (supported by ABP and uBO)

Used on https://www.filterlists.com/ and on my own site https://secure.fanboy.co.nz/
Sample:
abp:subscribe?location=https://secure.fanboy.co.nz/fanboy-problematic-sites.txt&title=Fanboy Problematic Sites

If this suggestion is out of the scope of this, I can create a separate report.

[pes10k]

I think that would be better to open as an issue in brave-core, and note in it that it would need to come after this issue is closed

[karenkliu]

Designs added!