Feature request: WebSocket client support in toolkit

[justparking]

There are increasingly more devices that support WebSockets to control them (e.g. the WLED project)

It's a protocol that lends itself to Nodel recipes nicely and would make a very handy addition to the Toolkit.

I've been looking at some very lightweight, simple libraries and these two look promising:

1. https://github.com/gusavila92/java-android-websocket-client
2. https://github.com/TooTallNate/Java-WebSocket

Either could be cleanly integrated into Nodel making use of the relevant threading and logging frameworks.

[justparking]

I've started on this. Making some notes for initial interfaces, for the record:

nodetoolkit.py

def WebSocket(dest=None, opened=None, textReceived=None, binaryReceived=None, pingReceived=None, pongReceived=None, exceptionReceived=None, closed=None):
    return nodetoolkit.createWebSocket(dest, opened, textReceived, binaryReceived, pingReceived, pongReceived, exceptionReceived, closed)
    # ...

ManagedToolkit.java

    // ...
    public ManagedWebSocket createWebSocket(
                                String dest,
                                H0 opened,
                                H1<String> textReceived,
                                H1<byte[]> binaryReceived,
                                H1<byte[]> pingReceived,
                                H1<byte[]> pongReceived,
                                H1<Exception> exceptionReceived,
                                H2<Integer, String> closed) {
    // ...

example script.py

def ws_opened():
  console.info("ws_opened")
  _ws.send("hello from nodel")
  
def ws_textReceived(text):
  console.info("ws_textReceived %s" % text)
  
def ws_binaryReceived(data):
  console.info("ws_binaryReceived %s" % data)
  
def ws_pingReceived(data):
  console.info("ws_pingReceived %s" % data)  

def ws_pongReceived(data):
  console.info("ws_pongReceived %s" % data)

def ws_exceptionReceived(exc):
  console.info("ws_exceptionReceived %s" % exc)

def ws_closed(i, msg):
  console.info("ws_closed %s %s" % (i, msg))

_ws = WebSocket(  opened=ws_opened,
                  textReceived=ws_textReceived,
                  binaryReceived=ws_binaryReceived,
                  pingReceived=ws_pingReceived,
                  pongReceived=ws_pongReceived,
                  exceptionReceived=ws_exceptionReceived,
                  closed=ws_closed)

def main():
  _ws.setDest("ws://192.168.10.5:80/ws")

build.gradle

dependencies { 
    // ...
    // websocket client
    compile 'dev.gustavoavila:java-android-websocket-client:2.0.2'

My initial concerns are:

1. can that set of callhandlers be minimised or is every one necessary
2. what's best way to pass byte[] types through to Jython - I might just do the same as Managed UDP/TCP classes
3. the java-android-websocket-client dependency have a very poor bespoke threading model which might required being transplanted into nodel as opposed to being used as a dependency, but need to asses other WebSocket client APIs too.