Skip to content

mandrewcito/signalrcore

Repository files navigation

SignalR core client

Donate Pypi Downloads Downloads Issues Open issues codecov.io

logo alt

Links

Develop

Test server will be avaiable in here and docker compose is required.

git clone https://github.com/mandrewcito/signalrcore-containertestservers
cd signalrcore-containertestservers
docker-compose up
cd ../signalrcore
make tests

Known Issues

Issues related with closing sockets are inherited from the websocket-client library. Due to these problems i can't update the library to versions higher than websocket-client 0.54.0. I'm working to solve it but for now its patched (Error number 1. Raises an exception, and then exception is treated for prevent errors). If I update the websocket library I fall into error number 2, on local machine I can't reproduce it but travis builds fail (sometimes and randomly :()

A Tiny How To

Connect to a server without auth

hub_connection = HubConnectionBuilder()\
    .with_url(server_url)\
    .configure_logging(logging.DEBUG)\
    .with_automatic_reconnect({
        "type": "raw",
        "keep_alive_interval": 10,
        "reconnect_interval": 5,
        "max_attempts": 5
    }).build()

Connect to a server with auth

login_function must provide auth token

hub_connection = HubConnectionBuilder()\
            .with_url(server_url,
            options={
                "access_token_factory": login_function,
                "headers": {
                    "mycustomheader": "mycustomheadervalue"
                }
            })\
            .configure_logging(logging.DEBUG)\
            .with_automatic_reconnect({
                "type": "raw",
                "keep_alive_interval": 10,
                "reconnect_interval": 5,
                "max_attempts": 5
            }).build()

Unauthorized errors

A login function must provide an error controller if authorization fails. When connection starts, if authorization fails exception will be propagated.

    def login(self):
        response = requests.post(
            self.login_url,
            json={
                "username": self.email,
                "password": self.password
                },verify=False)
        if response.status_code == 200:
            return response.json()["token"]
        raise requests.exceptions.ConnectionError()

    hub_connection.start()   # this code will raise  requests.exceptions.ConnectionError() if auth fails

Configure logging

HubConnectionBuilder()\
    .with_url(server_url,
    .configure_logging(logging.DEBUG)
    ...

Configure socket trace

HubConnectionBuilder()\
    .with_url(server_url,
    .configure_logging(logging.DEBUG, socket_trace=True) 
    ... 

Configure your own handler

 import logging
handler = logging.StreamHandler()
handler.setLevel(logging.DEBUG)
hub_connection = HubConnectionBuilder()\
    .with_url(server_url, options={"verify_ssl": False}) \
    .configure_logging(logging.DEBUG, socket_trace=True, handler=handler)
    ...

Configuring reconnection

After reaching max_attempts an exeption will be thrown and on_disconnect event will be fired.

hub_connection = HubConnectionBuilder()\
    .with_url(server_url)\
    ...
    .build()

Configuring additional headers

hub_connection = HubConnectionBuilder()\
            .with_url(server_url,
            options={
                "headers": {
                    "mycustomheader": "mycustomheadervalue"
                }
            })
            ...
            .build()

Configuring additional querystring parameters

server_url ="http.... /?myquerystringparam=134&foo=bar"
connection = HubConnectionBuilder()\
            .with_url(server_url,
            options={
            })\
            .build()

Congfiguring skip negotiation

hub_connection = HubConnectionBuilder() \
        .with_url("ws://"+server_url, options={
            "verify_ssl": False,
            "skip_negotiation": False,
            "headers": {
            }
        }) \
        .configure_logging(logging.DEBUG, socket_trace=True, handler=handler) \
        .build()

Configuring ping(keep alive)

keep_alive_interval sets the seconds of ping message

hub_connection = HubConnectionBuilder()\
    .with_url(server_url)\
    .configure_logging(logging.DEBUG)\
    .with_automatic_reconnect({
        "type": "raw",
        "keep_alive_interval": 10,
        "reconnect_interval": 5,
        "max_attempts": 5
    }).build()

Configuring logging

hub_connection = HubConnectionBuilder()\
    .with_url(server_url)\
    .configure_logging(logging.DEBUG)\
    .with_automatic_reconnect({
        "type": "raw",
        "keep_alive_interval": 10,
        "reconnect_interval": 5,
        "max_attempts": 5
    }).build()

Configure messagepack

from signalrcore.protocol.messagepack_protocol import MessagePackHubProtocol

HubConnectionBuilder()\
            .with_url(self.server_url, options={"verify_ssl":False})\
                ... 
            .with_hub_protocol(MessagePackHubProtocol())\
                ...
            .build()

Events

On Connect / On Disconnect

on_open - fires when connection is opened and ready to send messages on_close - fires when connection is closed

hub_connection.on_open(lambda: print("connection opened and handshake received ready to send messages"))
hub_connection.on_close(lambda: print("connection closed"))

On Hub Error (Hub Exceptions ...)

hub_connection.on_error(lambda data: print(f"An exception was thrown closed{data.error}"))

Register an operation

ReceiveMessage - signalr method print - function that has as parameters args of signalr method

hub_connection.on("ReceiveMessage", print)

Sending messages

SendMessage - signalr method username, message - parameters of signalrmethod

    hub_connection.send("SendMessage", [username, message])

Sending messages with callback

SendMessage - signalr method username, message - parameters of signalrmethod

    send_callback_received = threading.Lock()
    send_callback_received.acquire()
    self.connection.send(
        "SendMessage", # Method
        [self.username, self.message], # Params
        lambda m: send_callback_received.release()) # Callback
    if not send_callback_received.acquire(timeout=1):
        raise ValueError("CALLBACK NOT RECEIVED")

Requesting streaming (Server to client)

hub_connection.stream(
            "Counter",
            [len(self.items), 500]).subscribe({
                "next": self.on_next,
                "complete": self.on_complete,
                "error": self.on_error
            })

Client side Streaming

from signalrcore.subject import  Subject

subject = Subject()

# Start Streaming
hub_connection.send("UploadStream", subject)

# Each iteration
subject.next(str(iteration))

# End streaming
subject.complete()

Full Examples

Examples will be avaiable here It were developed using package from aspnet core - SignalRChat

Chat example

A mini example could be something like this:

import logging
import sys
from signalrcore.hub_connection_builder import HubConnectionBuilder


def input_with_default(input_text, default_value):
    value = input(input_text.format(default_value))
    return default_value if value is None or value.strip() == "" else value


server_url = input_with_default('Enter your server url(default: {0}): ', "wss://localhost:44376/chatHub")
username = input_with_default('Enter your username (default: {0}): ', "mandrewcito")
handler = logging.StreamHandler()
handler.setLevel(logging.DEBUG)
hub_connection = HubConnectionBuilder()\
    .with_url(server_url, options={"verify_ssl": False}) \
    .configure_logging(logging.DEBUG, socket_trace=True, handler=handler) \
    .with_automatic_reconnect({
            "type": "interval",
            "keep_alive_interval": 10,
            "intervals": [1, 3, 5, 6, 7, 87, 3]
        }).build()

hub_connection.on_open(lambda: print("connection opened and handshake received ready to send messages"))
hub_connection.on_close(lambda: print("connection closed"))

hub_connection.on("ReceiveMessage", print)
hub_connection.start()
message = None

# Do login

while message != "exit()":
    message = input(">> ")
    if message is not None and message != "" and message != "exit()":
        hub_connection.send("SendMessage", [username, message])

hub_connection.stop()

sys.exit(0)