Graphql-ruby: GraphQL Subscriptions

[nethsix]

@rmosolgo

Love this gem, we have it running in production albeit we are a super small shop. Thanks also for keeping our blog post on the graphql README.

• Are there any plans for GraphQL subscription (https://github.com/facebook/relay/issues/541), or it is already there? I looked through the code and saw that there are some declarations but no implementation yet?
• If it is not there yet, I would like to help. How long do you think it would take to implement the most basic form of it?

[rmosolgo]

Yes, right now support is pretty minimal: we accept a root subscription type and we execute subscription queries against that root. I'm not sure exactly what else the gem needs -- storing subscriptions and delivering payloads is very application-specific right?

I tinkered a while back to get this working on ActionCable:

• The cable builds a "subscriber" and sends it into GraphQL
• GraphQL registers subscriptions as needed
• Application logic can trigger subscriptions
• ... which causes the original query to be run again and delivered to the client

The basic bits are in place, but there are still a _few_ things to work out! For example:

• "Automatic" mapping of subscription fields + arguments to ActionCable broadcasts?
• Don't parse the query every time
• Better way than send(:transmit, ...) to stream to the client?

[nethsix]

Whoa...really nice!! Let me give this a shot. I would need to somehow install ActionCable though since I'm on Rails 4.2, and ActionCable is no longer available as a a separate gem.

Feel free to close this, or I can keep you posted on my attempt to make this work on my Rails app here or even somewhere else, whatever works best for you.

[rmosolgo]

One of our apps uses Pusher, I think it would be possible to implement something similar on top of that service instead of ActionCable

[nethsix]

Thanks for the tip!

[rmosolgo]

I extracted it to a gem here: https://github.com/rmosolgo/graphql-streaming

[nethsix]

Thank you as always! Love your work.