dyffi-bus-client 0.1.1

A async Pub/Sub client for Dyffi-Bus

DyffiClient

DyffiClient is a lightweight Python library for interacting with Dyffi-Bus via HTTP and WebSockets. It abstracts away the details of publishing messages and subscribing to topics, letting you focus on your application logic.

Installation

pip install dyffi-client

Usage

1. Create a Client

from dyffi_bus_client import DyffiBusClient

# Initialize the client with the base URL of your pub/sub service
client = DyffiBusClient("http://127.0.0.1:8000")

2. Publish Messages

message_id = client.publish("orders", {"order_id": 123, "customer": "Alice"})
print("Sent message with ID:", message_id)

• topic: The topic name to publish to.
• payload: A dictionary containing the message data.

3. Subscribe to a Topic

def order_handler(message):
    print("Got Message:", message)
    print("Order ID:", message["payload"]["order_id"])

client.subscribe("orders", order_handler, blocking=False)

• topic: The topic name to subscribe to.
• handler: A callback function that receives the message as a Python dictionary.
• blocking=False: The subscription runs in a separate thread, so your main program can continue doing other things.
  If you set blocking=True, the subscription loop will block the current thread until you stop it (e.g., with Ctrl+C).

4. Keep the Main Thread Alive (Optional)

If you used non-blocking subscriptions, you can call:

client.listen()

This starts a simple loop that keeps your script running indefinitely. Press Ctrl+C to stop.

Full Examples

Example: Publishing

from dyffi_bus_client import DyffiBusClient

client = DyffiBusClient("http://127.0.0.1:8000")

message_id = client.publish("orders", {"order_id": 123, "customer": "Alice"})
print("Sent message with ID:", message_id)

Example: Subscribing to Multiple Topics

from dyffi_bus_client import DyffiBusClient


def order_handler(message):
  print("Got Message:", message)
  print("Order ID:", message["payload"]["order_id"])


def topic_handler(message):
  print("Got Message:", message)


client = DyffiBusClient("http://127.0.0.1:8000")

# Subscribe to 'orders' in a non-blocking thread
client.subscribe("orders", order_handler, blocking=False)

# Subscribe to 'myTopic' in a blocking manner
client.subscribe("myTopic", topic_handler, blocking=True)

In this example:

• We listen to orders in a separate thread (non-blocking).
• We then subscribe to myTopic in blocking mode, so the program stays alive until we stop it.

How It Works

• publish(topic, payload)
  Sends an HTTP POST request to <api_url>/publish with the given topic and payload.
• subscribe(topic, handler, blocking=False)
  Opens a WebSocket connection to <api_url>/ws/<topic> in a separate thread, calling handler(message) for every new message.
  If blocking=True, it runs on the main thread until stopped.
• listen()
  A simple blocking loop that keeps the main thread alive if you used non-blocking subscriptions.

License

This library is provided under the MIT License. Feel free to open issues or submit pull requests if you encounter any problems or have ideas for new features.