Creating a plugin

You can, and probably need to, extend byro with custom Python code using the official plugin API. You’ll have to think of every plugin as an independent Django ‘app’ living in its own python package installed like any other python module.

The communication between byro and the plugins happens primarily using Django’s signal dispatcher feature. The core modules of byro expose signals for different purposes. You can find their documentation on the next pages. We also provide guides for common plugin use cases, such as tracking custom member data, or importing and matching payments.

To create a new plugin, create a new python package which must be a valid Django app and must contain plugin metadata, as described below. You will need some boilerplate code for every plugin to get started. To save your time, we created a cookiecutter template that you can use like this:

(env)$ pip install cookiecutter
(env)$ cookiecutter https://github.com/byro/byro-plugin-cookiecutter

This will ask you some questions and then create a project folder for your plugin.

The following pages go into detail about the different types of plugins byro supports. While these instructions don’t assume that you know a lot about byro, they do assume that you have prior knowledge about Django (e.g. its view layer, how its ORM works, etc.).

Plugin metadata

The plugin metadata lives inside a ByroPluginMeta class inside your app’s configuration class. The metadata class must define the following attributes:

Attribute	Type	Description
name	string	The human-readable name of your plugin
author	string	Your name
version	string	A human-readable version code of your plugin
description	string	A more verbose description of what your plugin does.

A working example, living in byro_irc/apps.py, would be:

from django.apps import AppConfig
from django.utils.translation import gettext_lazy as _


class IRCApp(AppConfig):
    name = 'byro_irc'
    verbose_name = _("IRC")

    class ByroPluginMeta:
        name = _("IRC")
        author = _("irclover")
        version = '1.0.0'
        visible = True
        description = _("This plugin sends notifications via IRC.")

Django picks up the single AppConfig subclass in your apps submodule automatically. If that module defines more than one AppConfig subclass, mark the one byro should use with default = True. The old default_app_config variable has no effect since Django 4.1 and should not be used.

Warning

byro registers your plugin in INSTALLED_APPS by its bare module name. If your AppConfig does not live in apps.py, Django falls back to a plain AppConfig without ByroPluginMeta. byro starts without an error, but silently ignores the plugin: its URLs are not included, it is not listed on the plugins page, its document categories are missing, and its ready() method never runs, so none of its signal receivers are connected.

Plugin registration

Somehow, byro needs to know that your plugin exists at all. For this purpose, we make use of the entry point mechanism. To register a plugin that lives in a separate python package, your pyproject.toml should contain something like this:

[project.entry-points."byro.plugin"]
byro_irc = "byro_irc:ByroPluginMeta"

byro only evaluates the module part before the colon and adds that module to INSTALLED_APPS; the part after the colon is a convention. If your project still uses a setup.py, the same entry goes into its entry_points argument under the [byro.plugin] group.

This will automatically make byro discover this plugin as soon as you have installed it, e.g. through pip. During development, install your plugin in editable mode with pip install -e . inside your plugin source directory to make it discoverable.

Signals

byro defines different signals which your plugin can listen for. We will go into the details of the different signals in the following pages. We suggest that you put your signal receivers into a signals submodule of your plugin. You should extend your AppConfig in apps.py (see above) by the following method to make your receivers available:

class IRCApp(AppConfig):
    …

    def ready(self):
        from . import signals  # noqa

Views

Your plugin may define custom views. If you put an urls submodule into your plugin module, byro will automatically import it and include it into the root URL configuration with the namespace plugins:<label>:, where <label> is your Django app label.

Warning

If you define custom URLs and views, you are on your own with checking that the user has appropriate permissions. byro ensures that you are dealing with an authenticated user, but nothing else.