- Based on the work by niv https://github.com/niv/websocket.nim
- Also see rfc https://tools.ietf.org/html/rfc6455
Example echo server, will repeat what you send it:
import ws, asyncdispatch, asynchttpserver
var server = newAsyncHttpServer()
proc cb(req: Request) {.async.} =
if req.url.path == "/ws":
var ws = await newWebSocket(req)
await ws.send("Welcome to simple echo server")
while ws.readyState == Open:
let packet = await ws.receiveStrPacket()
await ws.send(packet)
else:
await req.respond(Http404, "Not found")
waitFor server.serve(Port(9001), cb)And then in the browser type this JavaScript:
ws = new WebSocket("ws://localhost:9001/ws")
ws.send("hi")
Example chat server, will send what you send to connected all clients.
import ws, asyncdispatch, asynchttpserver
var connections = newSeq[WebSocket]()
proc cb(req: Request) {.async, gcsafe.} =
if req.url.path == "/ws":
try:
var ws = await newWebSocket(req)
connections.add ws
await ws.send("Welcome to simple chat server")
while ws.readyState == Open:
let packet = await ws.receiveStrPacket()
for other in connections:
if other.readyState == Open:
asyncCheck other.send(packet)
except WebSocketError:
echo "socket closed:", getCurrentExceptionMsg()
else:
await req.respond(Http404, "Not found")
var server = newAsyncHttpServer()
waitFor server.serve(Port(9001), cb)In one tab:
ws = new WebSocket("ws://localhost:9001/ws")
ws.send("How are you?")Other tab:
ws = new WebSocket("ws://localhost:9001/ws")
ws.send("Good, you?")Instead of being the server you are the client connecting to some other server:
var ws = await newWebSocket("ws://127.0.0.1:9001/ws")
echo await ws.receiveStrPacket()
await ws.send("Hi, how are you?")
echo await ws.receiveStrPacket()
ws.close()SSL is also supported:
var ws = await newWebSocket("wss://echo.websocket.org")You can also pass a protocol
var ws = await newWebsocket("wss://echo.websocket.org", protocol = "alpha")If you use using ws with jester library you need to import jester_extra:
import jester
import ws, ws/jester_extra
routes:
get "/ws":
var ws = await newWebSocket(request)
await ws.send("Welcome to simple echo server")
while ws.readyState == Open:
let packet = await ws.receiveStrPacket()
await ws.send(packet)import wsReadyState = enum
Connecting = 0, Open = 1, Closing = 2, Closed = 3WebSocket = ref object
req*: Request
version*: int
key*: string
protocol*: string
readyState*: ReadyState
WebSocketError = object of ExceptionCreates a new socket from a request.
proc newWebSocket(req: Request): Future[WebSocket] {.async, raises: [WebSocketError].}4 bits. Defines the interpretation of the "Payload data".
Opcode = enum
Cont = 0x00000000, ## denotes a continuation frame
Text = 0x00000001, ## denotes a text frame
Binary = 0x00000002, ## denotes a binary frame
Close = 0x00000008, ## denotes a connection close
Ping = 0x00000009, ## denotes a ping
Pong = 0x0000000A ## denotes a pongThis is the main method used to send data via this WebSocket.
proc send(ws: WebSocket; text: string; opcode = Opcode.Text): Future[void] {.async, raises: [WebSocketError], tags: [WriteIOEffect, ReadIOEffect].}Wait for a string or binary packet to come in.
proc receivePacket(ws: WebSocket): Future[(Opcode, string)] {.async, raises: [WebSocketError].}Wait only for a string packet to come. Errors out on Binary packets.
proc receiveStrPacket(ws: WebSocket): Future[string] {.async, raises: [WebSocketError].}Wait only for a binary packet to come. Errors out on string packets.
proc receiveBinaryPacket(ws: WebSocket): Future[seq[byte]] {.async, raises: [WebSocketError].}Sends a ping to the other end, both server and client can send a ping. Data is optional.
proc ping(ws: WebSocket; data = "") {.async.}proc setupPings(ws: WebSocket; seconds: float)Closes the Socket without sending a close packet
proc hangup(ws: WebSocket) {.raises: [WebSocketError].}Close the Socket, sends close packet.
proc close(ws: WebSocket)