signalrcore 0.8.1

A Python SignalR Core client, with invocation auth and two way streamming. Also automatic reconnect and manually reconnect

SignalR core client

Links

• Dev to posts with library examples and implementation

• Pypy

• Wiki - This Doc

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()

Configuring reconection

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

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

Configuring aditional headers

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

Configuring aditional querystring parameters

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

Configuring ping(keep alive)

keep_alive_interval sets the secconds 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()

Events

On connect / On disconnect

on_open - fires when connection is openned 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"))

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])

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

Using package from aspnet core - SignalRChat example chat without auth

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}): ', "ws://localhost:62342/chathub")
username = input_with_default('Enter your username (default: {0}): ', "mandrewcito")

hub_connection = HubConnectionBuilder().with_url(server_url).with_automatic_reconnect({
        "type": "raw",
        "keep_alive_interval": 10,
        "reconnect_interval": 5,
        "max_attempts": 5
    }).build()
hub_connection.on("ReceiveMessage", print)
hub_connection.start()
message = None
# Do login

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

Using package from aspnet core - SignalRAuthenticationSample ,

Example with Auth

import requests
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


def signalr_core_example_login(url, user, username_password):
    response = requests.post(url, data={"email": user, "password": username_password})
    return response.json()["token"]


login_url = input_with_default('Enter your server login url({0}):', "http://localhost:50746/account/token")
server_url = input_with_default('Enter your server url(default: {0}): ', "ws://localhost:50746/hubs/chat")
username = input_with_default('Enter your username (default: {0}): ', "[e-mail]")
password = input_with_default('Enter your password (default: {0}): ', "Abc123.--123?")

hub_connection = HubConnectionBuilder()\
    .with_url(server_url, options={
        "access_token_factory": lambda: signalr_core_example_login(login_url, username, password)
    }).with_automatic_reconnect({
        "type": "interval",
        "keep_alive_interval": 10,
        "intervals": [1, 3, 5, 6, 7, 87, 3]
    })\
    .build()

hub_connection.on("ReceiveSystemMessage", print)
hub_connection.on("ReceiveChatMessage", print)
hub_connection.on("ReceiveDirectMessage", print)
hub_connection.start()
message = None
while message != "exit()":
    message = input(">> ")
    if message is not None and message is not "" and message is not "exit()":
        hub_connection.send("Send", [message])
hub_connection.stop()

Example with streaming

Using package from aspnet core - SignalRStreaming ,

import time
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}): ', "ws://localhost:57957/streamHub")

hub_connection = HubConnectionBuilder().with_url(server_url).build()
hub_connection.start()
time.sleep(10)


def bye(error, x):
    if error:
        print("error {0}".format(x))
    else:
        print("complete! ")
    global hub_connection
    hub_connection.stop()
    sys.exit(0)


hub_connection.stream(
    "Counter",
    [10, 500]).subscribe({
        "next": lambda x: print("next callback: ", x),
        "complete": lambda x: bye(False, x),
        "error": lambda x: bye(True, x)
    })

Example with client side streaming

Using package from aspnet core - SignalRStreaming ,

from signalrcore.hub_connection_builder import HubConnectionBuilder
from signalrcore.subject import Subject


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")

hub_connection = HubConnectionBuilder()\
    .with_url(server_url, options={"verify_ssl": False}) \
    .configure_logging(logging.DEBUG) \
    .with_automatic_reconnect({
            "type": "interval",
            "keep_alive_interval": 10,
            "intervals": [1, 3, 5, 6, 7, 87, 3]
        })\
    .build()
hub_connection.start()
time.sleep(10)


def bye(error, x):
    if error:
        print("error {0}".format(x))
    else:
        print("complete! ")
    global hub_connection
    hub_connection.stop()
    sys.exit(0)


iteration = 0
subject = Subject()


def interval_handle():
    global iteration
    iteration += 1
    subject.next(str(iteration))
    if iteration == 10:
        subject.complete()


hub_connection.send("UploadStream", subject)

while iteration != 10:
    interval_handle()
    time.sleep(0.5)