ki2-simple-mqtt 0.1.2

SimpleMqtt is a Python library designed to simplify MQTT client operations. It extends the Paho MQTT client to provide enhanced functionality while maintaining a clean and flexible interface. Whether you're building synchronous or asynchronous applications, SimpleMqtt has you covered.

SimpleMqtt

SimpleMqtt is a Python library designed to simplify MQTT client operations. It extends the Paho MQTT client to provide enhanced functionality while maintaining a clean and flexible interface. Whether you're building synchronous or asynchronous applications, SimpleMqtt has you covered.

Features

• Enhanced Callback Management: Manage multiple callbacks for each event type (on_connect, on_disconnect, on_message) seamlessly.
• Topic-Specific Callbacks: Easily associate callbacks with specific topics or topic patterns, simplifying message handling.
• Deferred Subscriptions: Automatically handles subscriptions made before a connection is established, applying them as soon as the connection is active.
• Dual-Mode Clients: Provides both synchronous (SimpleMqttSync) and asynchronous (SimpleMqttAsync) clients.
• Callback Flexibility: Supports both synchronous and asynchronous callbacks, regardless of the client type.
• JSON Integration: Publish and receive JSON messages effortlessly with built-in serialization and deserialization support.

Why SimpleMqtt?

While Paho MQTT is a robust library for working with MQTT, SimpleMqtt enhances its capabilities by:

1. Allowing multiple callbacks to be registered for each event (on_connect, on_disconnect, on_message).
2. Providing a straightforward mechanism to bind callbacks to specific topics or patterns (e.g., home/+/temperature).
3. Simplifying the callback interface by encapsulating event data in a single parameter.
4. Handling subscriptions even if they are made before a connection is established.
5. Offering synchronous and asynchronous client implementations with uniform features.
6. Adding native support for JSON serialization and deserialization.

Installation

Install the library via pip:

pip install ki2-simple-mqtt

Getting Started

Here are quick examples to get you started:

Synchronous Example

from SimpleMqtt import SimpleMqttSync, OnConnectEvent, OnDisconnectEvent, OnMessageEvent

def on_connect(event: OnConnectEvent):
    print(f"Connected (rc={event.reason_code})")

def on_disconnect(event: OnDisconnectEvent):
    print(f"Disconnected (rc={event.reason_code})")

def on_message(event: OnMessageEvent):
    print(f"Message received on {event.topic}: {event.payload}")

mqtt = SimpleMqttSync()

mqtt.on_connect(on_connect)
mqtt.on_disconnect(on_disconnect)
mqtt.on_message(on_message)

mqtt.subscribe("test/topic")  # Deferred if not connected
mqtt.connect("localhost")

mqtt.loop_forever()

Asynchronous Example

import asyncio
from SimpleMqtt import SimpleMqttAsync, OnMessageEvent

async def on_message(event: OnMessageEvent):
    print(f"Message received on {event.topic}: {event.payload}")

async def main():
    mqtt = SimpleMqttAsync()

    mqtt.on_message(on_message)

    await mqtt.subscribe("test/topic")  # Deferred if not connected
    await mqtt.connect("localhost")

    try:
        await mqtt.loop()
    except KeyboardInterrupt:
        print("Disconnecting...")
        await mqtt.disconnect()

if __name__ == "__main__":
    asyncio.run(main())

Key Features

Multiple Callbacks per Event

SimpleMqtt allows you to register multiple callbacks for the same event. For example, you can have separate callbacks to log connection events and update a user interface:

def log_connection(event):
    print(f"Logging: Connected with code {event.reason_code}")

def notify_user(event):
    print("User notified of connection")

mqtt.on_connect(log_connection)
mqtt.on_connect(notify_user)

Topic-Specific Callbacks

Bind callbacks directly to topics or patterns for targeted message handling:

def custom_handler(event):
    print(f"Custom handler for {event.topic}: {event.payload}")

mqtt.on_topic_message("home/+/temperature", custom_handler)

Deferred Subscriptions

SimpleMqtt simplifies handling subscriptions by allowing them to be registered before the client is connected. These subscriptions are automatically applied once the connection is established:

mqtt.subscribe("test/topic")  # Can be called before connecting
mqtt.connect("localhost")

Synchronous and Asynchronous Callback Support

Both clients (SimpleMqttSync and SimpleMqttAsync) support synchronous and asynchronous callbacks, making it easy to integrate into a variety of application architectures.

async def async_handler(event):
    await some_async_operation()
    print(f"Async handled message on {event.topic}")

mqtt.on_message(async_handler)

JSON Integration

SimpleMqtt simplifies working with JSON by supporting direct serialization and deserialization. For instance:

Publishing JSON

mqtt.publish("sensor/data", {"temperature": 22.5, "humidity": 60})

Receiving JSON

def handle_json_message(event: OnMessageEvent):
    data = event.as_json  # Automatically deserializes payload into a Python dictionary
    print(f"Received JSON data: {data}")

mqtt.on_message(handle_json_message)

Advanced Usage

Managing QoS and Retained Messages

Fine-tune QoS and retained message settings for better control over message delivery:

mqtt.subscribe("test/topic", qos=1)
mqtt.publish("test/topic", "Hello, MQTT!", retain=True)

Limitations

While SimpleMqtt provides many enhancements over the base Paho MQTT library, there are some limitations to be aware of:

1. Feature Scope: SimpleMqtt prioritizes simplicity and usability, so some advanced or less commonly used Paho MQTT features might not be directly exposed.
2. Connection-Dependent Subscriptions: Deferred subscriptions only apply to topics registered using subscribe methods. Direct use of the underlying Paho client bypasses this mechanism.
3. Incompatibility with Existing Paho Callbacks: SimpleMqtt uses a simplified callback signature with a single parameter encapsulating all event data. This means that existing callbacks designed specifically for Paho's native interface cannot be reused directly with SimpleMqtt.

License

This project is licensed under the MIT License. See the LICENSE file for details.