Fetch linked channels

[PhilC813]

Checklist

• I am aware that this issue is being opened for the NewPipe Extractor, NOT the app, and my feature request will be dismissed otherwise.
• I made sure that there are no existing issues - open or closed - which I could contribute my information to.
• I have taken the time to fill in all the required details. I understand that the feature request will be dismissed otherwise.
• This issue contains only one feature request.
• I have read and understood the contribution guidelines.

Feature description

Some channels (eg, LTT) add references to other channels, usually others they operate, on the home tab of their channel. It doesn't seem currently possible to fetch these linked channels using NewPipeExtractor.

Why do you want this feature?

I'm an end user of LibreTube. I opened an issue on their repo first, and the dev referred me to here since the extractor doesn't support fetching this data.

I'd like the feature because it would make onboarding in YouTube third-party clients easier overall, when the user needs to quickly add the channels he wants to subscribe to.

Additional information

No response

[ChanGu3]

I'm fairly new to this repo and have been studying it a bit I would like to give this a shot.

[ChanGu3]

Quick update,

I've finished a solution and did the testing for it and everything passed but still want to double check things a little more though. The main issue I ran into was trying to figure out where to extract the featured channels since the only place I could find them is on the home (also known as "feature") page like you mentioned. This was a problem because users can set up featured channels in any order on the page they want and have multiple or none. I'll be making a PR request hopefully in a couple days after putting everything I need together and possibly more tests if necessary.

Solution Summary:
I wanted to describe my solution as I feel the need too ill be doing this in better detail and format in my pull request. I re-used the ChannelInfoItems for the eventual extracted featured channels. I added the ability for the Feature tab to be fetched utilizing the ChannelTabExtractor and populating the collector list with what I call RenderListInfoItems this will hold the item type, renderer list name (like "Featured Channels"), and ListLinkHandler for that category. The idea is you would use the ListLinkHandler to retrieve the items in another Extractor that pulls from the same url of course where the handler contains the information for the specific index it is located. Implementing a abstract ChannelListExtractor I was able to use the url and the index from the listlinkhandler to get a continuation token on the page where I could extract the featured channels and do so continuously using T-series as an example since they have many Featured Channels XD.

Apologies if this was long winded but I'm hoping someone can read over this possibly to see if I had the right idea.