Example

var server = newAsyncHttpServer()
proc cb(req: Request) {.async.} =
  
  let (success, error) = await(verifyWebsocketRequest(req, "myfancyprotocol"))
  if not success:
    echo "WS negotiation failed: " & error
    await req.respond(Http400, "Websocket negotiation failed: " & error)
    req.client.close
  
  else:
    echo "New websocket customer arrived!"
    while true:
      try:
        var f = await req.client.readData(false)
        echo "(opcode: " & $f.opcode & ", data: " & $f.data.len & ")"
        
        if f.opcode == Opcode.Text:
          waitFor req.client.sendText("thanks for the data!", false)
        else:
          waitFor req.client.sendBinary(f.data, false)
      
      except:
        echo getCurrentExceptionMsg()
        break
    
    req.client.close()
    echo ".. socket went away."

Imports

asyncnet, asyncdispatch, asynchttpserver, strtabs, base64, securehash, strutils, sequtils, private/hex, shared

Procs

proc verifyWebsocketRequest*(req: Request; protocol = ""): Future[ tuple[valid: bool, error: string]] {.async.}

Verifies the request is a websocket request:

Supports protocol version 13 only
Does not support extensions (yet)
Will auto-negotiate a compatible protocol based on your protocol param

If all validations pass, will give you a tuple (true, ""). You can pass in a empty protocol param to not perform negotiation; this is the equivalent of accepting all protocols the client might request.

If the client does not send any protocols, but you have given one, the request will fail.

If validation FAILS, the response will be (false, human-readable failure reason).

After successful negotiation, you can immediately start sending/reading websocket frames.

Source

Module server

Example

Imports

Procs