• Overview
• Technical requirements
• Specification requirements
• Supported protocols
• How to use the template
• Template configuration
• Development

Overview

This template generates MQTT Python client module. Its purpose is to abstract for the application client technical information about the broker and the names of topics it should use. Instead, it generates a module that provides a set of indent-driven functions that one can invoke to send or receive messages to the application through the message broker.

Technical requirements

1.10.0 =< Generator < 2.0.0

Specification requirements

The table contains information on parts of the specification required by this template to generate the proper output.

Property name	Reason	Fallback	Default
channels.{channel}.{operation}.operationId	To generate function names it is required to specify them in AsyncAPI document through operationId field.	-	-

Supported protocols

MQTT

How to use the template

• Install AsyncAPI CLI
• Make sure you have Python 3

Generate code:

asyncapi generate fromTemplate https://raw.githubusercontent.com/derberg/python-mqtt-client-template/main/test/fixtures/asyncapi.yml https://github.com/derberg/python-mqtt-client-template --output myclient --force-write --param server=dev

You can also clone this template locally and run npm test to check it in action based on examples. Just remember to use some client to verify if tests are really sending or receiving messages to the broker.

Subscribe to a broker to see if the test is sending messages properly:

docker run hivemq/mqtt-cli sub -t comment/liked -h test.mosquitto.org

Publish to a broker to see if the test is consuming messages properly:

docker run hivemq/mqtt-cli pub -t comment/views -h test.mosquitto.org -m receiving-messages

Template configuration

You can configure this template by passing different parameters in the AsyncAPI CLI: -p PARAM1_NAME=PARAM1_VALUE PARAM2_NAME=PARAM2_VALUE

Name	Description	Required	Default	Allowed Values	Example
server	The server you want to use in the code.	Yes	-	-	production

Development

The most straightforward command to generate code on local during development is:

npm run test:example

We added jest snapshots to cover the integration tests, and you can run:

npm test

For local development, you need different variations of this command. First of all, you need to know about three important CLI flags:

• --debug enables the debug mode in Nunjucks engine what makes filters debugging simpler.
• --watch-template enables a watcher of changes that you make in the template. It regenerates your template whenever it detects a change.
• --install enforces reinstallation of the template.