mqroute 0.4.0

MQRoute is a Python library designed to simplify working with MQTT

MQRoute

MQRoute is a Python MQTT routing library designed to simplify working with MQTT topics by abstracting complexity. It supports advanced topic matching (including wildcards and parameterized topics), allows easy registration of callbacks using decorators, and provides scalable asynchronous callback handling.

Whether you're building an IoT platform or a messaging service, MQRoute makes it easy to manage MQTT subscriptions, streamline message processing, and publish messages to MQTT topics with minimal effort.

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Features

• Flexible Publishing:
  Easily publish messages to MQTT topics with simple method calls. Supports both JSON and raw payloads.

• Dynamic Topic Matching:
  Supports + and # MQTT wildcards, as well as parameterized topics (+parameter_name+) for extracting parameters from topic strings.

• Asynchronous by Design:
  Built with asyncio for responsive handling of incoming MQTT messages and user-defined asynchronous callbacks.

• Decorator-Based Callbacks:
  Subscribe to MQTT topics effortlessly using Python decorators.

• Type Safety:
  Includes type hints and validation with the typeguard library.

• Extensive Logging and Debugging:
  Detailed logs for easy troubleshooting of MQTT operations and callbacks.

• Customizable Payload Handling:
  Easy-to-use mechanisms for handling raw or JSON-formatted payloads.

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Installation

You can install MQRoute simply by using pip:

pip install mqroute

You may also download it from GitHub, for example, when local modifications are needed. That's your call!

Getting Started

Publish Messages

MQRoute makes it simple to publish messages to any topic, and it supports JSON encoding by default. Use the publish method for synchronous publishing or publish_async for asynchronous needs.

Below are the steps to start using MQRoute. For more advanced usage, refer to detailed examples in the testclient.py.

Initialize the MQTT Client

Use the MQTTClient class to connect to the MQTT broker, subscribe to topics, and handle messages.

import asyncio
from mqroute.mqtt_client import MQTTClient

mqtt = MQTTClient(host="test.mosquitto.org", port=1883)
asyncio.run(mqtt.run())  # Establishes connection and starts listening

Subscribe to Topics

Use the @mqtt.subscribe decorator to register a specific callback for a topic. The library supports + and # MQTT wildcards and parameterized topics.

@mqtt.subscribe(topic="devices/+/status")
async def handle_device_status(topic, msg, params):
    print(f"Device {params[0]} status: {msg.message}")

@mqtt.subscribe(topic="sensors/+/data/+/type/#")
async def handle_sensor_data(topic, msg, params):
    print(f"Sensor {params[0]} data at {params[1]}: {msg.message}")

Publish to Topics

Use the @mqtt.publish decorator to register a specific method to publish message to topic. The return value that is either dict or str will be send to this topic. For more complex cases the functional interface is also available.

async def publish_reset_command(*args, **kwargs):
    # any parameters can be added to the signature
    await mqtt.async_publish_message(topic="devices/thing/command", payload="do_reset")
    
def publish_restart_command(*args, **kwargs):
    # any parameters can be added to the signature
    mqtt.publish_message(topic="devices/thing/command", payload="do_restart")

@mqtt.publish(topic="devices/thing/command")
def publish_send_status_command(*args, **kwargs):
    # any parameters can be added to the signature
    return "send_status"

@mqtt.publish(topic="devices/thing/command")
async def publish_do_factory_reset(passkey: str):
    # any parameters can be added to the signature
    return f"do_factory_reset {passkey}"

Handle JSON Payloads Automatically

JSON payloads are converted automatically to dictionaries. If this behavior is not desired, set the raw_payload parameter in the decorator to True to receive raw data in the callback instead. The value of raw_payload defaults to False. Callbacks can also be marked as fallback, meaning they are only called if a topic doesn't match any non-fallback subscriptions. Note: Multiple fallback methods can be defined, and multiple fallbacks may match and thus be called.

@mqtt.subscribe(topic="config/update/json")
async def handle_config_update1(topic, msg, params):
    # Access the payload as a Python dictionary
    config_data_as_dict = msg.message
    print(f"Received config update: {config_data_as_dict}")

@mqtt.subscribe(topic="config/update/raw", raw_payload=True)
async def handle_config_update2(topic, msg, params):
    # Access the payload as a raw string
    config_data_as_raw = msg.message
    print(f"Received config update: {config_data_as_raw}")
    
@mqtt.subscribe(topic="config/#", raw_payload=True, fallback=True)
async def handle_config_update3(topic, msg, params):
    # Access the payload as a raw string
    config_data_as_raw = msg.message
    print(f"Received config update: {config_data_as_raw}")

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Custom signal handling for terminating application

Custom termination logic can be applied by using decorator sigint:

@mqtt.sigint
async def sigint_handler():
    # termination requested
    print(f"Received request to terminate application.")

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Example: Full Client Code

Below is an updated example that demonstrates how to use MQRoute: The updated example below demonstrates how to use MQRoute for subscribing to and publishing MQTT messages:

import asyncio
from mqroute.client import MQTTClient
from mqroute.mqtt_client import MQTTClient

mqtt = MQTTClient(host="mqtt.example.com", port=1883)


@mqtt.subscribe(topic="devices/+/status")
async def handle_device_status(topic, msg, params):
    print(f"Device {params[0]} status: {msg.message}")


@mqtt.subscribe(topic="sensors/+/status", raw_payload=True)
async def handle_sensor_status(topic, msg, params):
    sensor_id = params[0]
    print(f"Sensor {sensor_id} received raw status: {msg.message}")

@mqtt.subscribe(topic="sensors/#", fallback=True)
async def handle_sensor_data(topic, msg, params):
    print(f"Sensor data received on topic {topic}: {msg.message}")
    
@mqtt.sigint
async def sigint_handler():
    # termination requested
    print(f"Received request to terminate application.")

    
async def handle_green_light_status(topic, msg, params):
    print(f"Green sensor status: {msg.message}")

async def handle_green_light_status(topic, msg, params):
    print(f"Green sensor status: {msg.message}")

async def publish_example():
    # Publish using JSON payload and more explicit functional interface
    await mqtt.publish(topic="devices/control", payload={"command": "restart", "timeout": 5})

@mqtt.publish(topic="raw/commands")    
async def publish_example2(data: str):
    # Publish using raw payload and simpler decorated interface
    return f"Raw data string with parameter '{data}'"


async def main(): 
    # callback can also be added using functional interface.
    mqtt.add_subscription(handle_green_light_status,
                          topic="sensors/green/status")
    await mqtt.run()
    
    # Include publishing example
    await publish_example()
    await publish_example2("this data")
    
    # Keep the client running
    while mqtt.running:
        await asyncio.sleep(0.1)


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

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Advanced Features

1. Parameterized Topics

Extract dynamic portions of a topic using parameterized syntax:

@mqtt.subscribe(topic="room/+room+/device/+device+/status")
async def handle_parametrized(topic, msg, params):
    print(f"Device {params['device']} in room {params['room']} has status: {msg.message}")

2. Custom Callback Runner

For advanced use cases, directly manage callbacks using the CallbackRunner class.

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Testing

Integration and unit testing can be performed using pytest. Sample test cases are provided in the repository.

Run the tests:

pytest tests/

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Planned Improvements

• Customization and extendability: Allow easy means to support for example custom payload formats
• Demo environment: Demo environment with mqtt router and two mqroute clients talking. This would allow demo client to not depend on test.mosquitto.org demo client to not depend on third-party MQTT brokers.

Contributing

Contributions and feedback are welcome! If you'd like to contribute, please follow these steps:

1. Fork the repository.
2. Create a feature branch (git checkout -b feature-name).
3. Commit your changes (git commit -m 'Add new feature').
4. Push to the branch (git push origin feature-name).
5. Submit a pull request.

For major changes, please open an issue first to discuss what you'd like to improve.

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License

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

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Additional Notes

• For complete functionality and advanced examples, refer to the testclient.py file provided in the repository.
• MQRoute is in active development. Feel free to report bugs.