ws experiment

[meztez]

Related: #723

You get an Error in wsSend(private$wsObj, msg) : invalid state when you try to use websockets while a request is being processed by the regular REST API over http.

I've yet to find a way to leverage websockets over regular plumbing, this need more thinking.

PR task list:

• Update NEWS
• Add tests
• Update documentation with devtools::document()

[meztez]

I think this is more interesting.

api

#* @post /sleeper
#* @get /sleeper
#* @param payload:df
#* @parser json
#* @serializer unboxedJSON
function(payload = matrix(1:8, 2, 4), req) {
  a <- rowSums(payload)
  req$ws$send("Almost done")
  b <- colSums(payload)
  req$ws$send("Calculation completed")
  list(a, b)
}

Using websockets

ws <- websocket::WebSocket$new("ws://127.0.0.1:3946/sleeper")
ws$onMessage(function(res) { cat(res$data, "\n") })
ws$send('{"payload":[[1,3,5,7],[2,4,6,8]]}')
ws$close()

results

> ws <- websocket::WebSocket$new("ws://127.0.0.1:9629/sleeper")
> ws$onMessage(function(res) { cat(res$data, "\n") })
> ws$send('{"payload":[[1,8,5,7],[2,5,6,50]]}')
Almost done 
Calculation completed 
_status_ 200 
_headers_ Content-Type=application/json 
_body_ nextmessage 
[[21,63],[3,13,11,57]] 
> ws$close()

Then you can get intermediate response before getting the final response. Still use case to cover, I think this is a good start.

[meztez]

It probably makes more sense to only return res$body in websockets context?

[meztez]

Would websockets bypass cookie or apikey filter?

Most likely they should not be enabled by default.

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