Changing socket endpoint before reconnection

[jgafar]

We're using your javascript library (1.6.15) at Adobe for Project Neo to connect to a socket. Our socket endpoint is generated using a signed url and once the socket connection is established, that endpoint becomes invalidated (meaning you cannot use it to reconnect again). The library handles reconnection automatically, but the issue I'm running into is that it won't let me change the socket endpoint before attempting to reconnect. Since the endpoint has become invalidated, the reconnection always fails.

I was wondering if there was a way around this, or if there were any plans to accommodate this in the near future?

[chrismccord]

What does the "endpoint" auth mechanism look like? A token in the query string? A header? A segmented path? A different host? We may have existing primitives to already take care of this for you, but need to know more about what you need. Thanks!

[jgafar]

What does the "endpoint" auth mechanism look like? A token in the query string? A header? A segmented path? A different host? We may have existing primitives to already take care of this for you, but need to know more about what you need. Thanks!

Hi Chris,

We make a couple async calls to get a gateway signature then we append it along with a token to the socket url as query params.

[03juan]

@jgafar sounds like you're maybe crafting your own endpoint url but the only thing that should change between reconnects are the query params? i.e. you effectively call

let {signature, token} = await fancyAsyncRevalidator()
new Socket(`/app_socket_endpoint?signature=${signature}&token=${token}`, {...opts})

If so you should be able to pass a params function into opts to read latest the async query results:

let signedUrlParamsObject = await fancyAsyncRevalidator() 
let opts = {params: () => signedUrlParamsObject}
let socket = new Socket("/app_socket_endpoint", opts)
socket.onClose(() => fancyAsyncRevalidator().then(newParams => {
  signedUrlParamsObject = newParams
}))

Note this is fire-and-forget, so the socket reconnections may race the async revalidator

Refs to v1.6.15

phoenix/assets/js/phoenix/socket.js

Line 81 in bd275cf

* @param {(Object|function)} [opts.params] - The optional params to pass when connecting

phoenix/assets/js/phoenix/socket.js

Lines 221 to 237 in bd275cf

	connect(params){
	if(params){
	console && console.log("passing params to connect is deprecated. Instead pass :params to the Socket constructor")
	this.params = closure(params)
	}
	if(this.conn){ return }
	this.connectClock++
	this.closeWasClean = false
	this.conn = new this.transport(this.endPointURL())
	this.conn.binaryType = this.binaryType
	this.conn.timeout = this.longpollerTimeout
	this.conn.onopen = () => this.onConnOpen()
	this.conn.onerror = error => this.onConnError(error)
	this.conn.onmessage = event => this.onConnMessage(event)
	this.conn.onclose = event => this.onConnClose(event)
	}

phoenix/assets/js/phoenix/socket.js

Lines 189 to 196 in bd275cf

	endPointURL(){
	let uri = Ajax.appendParams(
	Ajax.appendParams(this.endPoint, this.params()), {vsn: this.vsn})
	if(uri.charAt(0) !== "/"){ return uri }
	if(uri.charAt(1) === "/"){ return `${this.protocol()}:${uri}` }
	return `${this.protocol()}://${location.host}${uri}`
	}