Are there plans to implement signalR hub / websockets for `{ json:api }` operations?

[NullVoxPopuli]

With operations over sockets (or a SignalR Hub), it'd be possible to :

• subscribe to certain URLs
  • with include, fields, etc, this would be the most similar to GraphQL's "Queries"
• to asynchronously receive new data whenever the server decides you need it.
  • better two-way communication
  • have quicker reassurance with optimistic UIs, or quicker feedback if something goes wrong
  • quicker UI updates with pessimistic UIs
• push any data down the socket at any time from any direction -- which may be a smidge faster, because the connection is already established.

[NullVoxPopuli]

A rough implementation lives on over here: sillsdev/appbuilder-portal#504

Some key points of interest:

• SignalR "Hub" mounted at /hubs/data: https://github.com/sillsdev/appbuilder-portal/pull/504/files#diff-588e201e0899badfabf44b3dc2a863ffR196 (could be anywhere though afaik)
• the Hub (thing that handles subscriptions / incoming data): https://github.com/sillsdev/appbuilder-portal/pull/504/files#diff-d6af4229367571a58deaf70c48c76fecR24
  • notes on subscribing to resources / individual record updates: https://github.com/sillsdev/appbuilder-portal/pull/504/files#diff-d6af4229367571a58deaf70c48c76fecR35
  • how handling incoming operations payloads happens: https://github.com/sillsdev/appbuilder-portal/pull/504/files#diff-d6af4229367571a58deaf70c48c76fecR53
• some hacking I had to do, because I didn't know of a way to serialize { json:api } documents without a bunch of context: https://github.com/sillsdev/appbuilder-portal/pull/504/files#diff-343c7a12f38b97e20ca232021e1e039aR90
• how a resource gets pushed to subscribers: https://github.com/sillsdev/appbuilder-portal/pull/504/files#diff-343c7a12f38b97e20ca232021e1e039aR135
• on the react side, this is how subscribing to resources is initiated: https://github.com/sillsdev/appbuilder-portal/pull/504/files#diff-851df6a1a003c7095d96c8c29f6ec64fR28