Support custom source types

[lucaswoj]

This is an umbrella issue meant to track the various moving pieces of getting our custom source API ready for primetime. I created a project for this but am having trouble adding issues to it.

• Support custom attribution strings
• Refactor "Worker", "Dispatcher", "Actor" into a general purpose "PooledWorker" utility
• Refactor source interface to better accommodate non-tiled sources
• Refactor GeoJSONSource as a composition VectorTileSource
• Add a Map#addCustomSource(...) method
• Document the custom source API
• Allow sources to specify their own validation logic

[lucaswoj]

👉 https://github.com/mapbox/mapbox-gl-js/projects/2

[remster]

Hey Lucas. I just forked mapbox-gl-js to achieve something similar. I need to override some of the VectorTileWorkerSource's behaviour...
The reference to which is hardcoded here as i type this and will hopefully remain in vicinity when you hopefully read this.

I understand that ultimately the ambition is for this mapping:
this.workerSourceTypes = { vector: VectorTileWorkerSource, geojson: GeoJSONWorkerSource };
to be supplied (in one gulp or increments) by the client (whoever constructed the mapboxgl.Map(...)) <- possibly in its c'tor params.

I am asking because as much as i can survive on my fork until your work is complete, i'd hate making wrong assumptions about where this goes. I've been trying to deduct it from your work's outline, say #3034, perhaps didn't read carefully enough, but couldn't really reassure myself.

BTW: is it in active development at present?
Perhaps there is something i could help with.

[lucaswoj]

Thanks for asking @remster. You can see the outstanding tasks for this refactor in in https://github.com/mapbox/mapbox-gl-js/projects/2. If you're serious about tackling any of those issues, let me know and I'll be sure to connect you with whatever help/resources you need.

[lucaswoj]

Based on current internal priorities, we aren't actively developing the custom source API right now. You can see our roadmap here: https://www.mapbox.com/mapbox-gl-js/roadmap/