Plugins

Plugins are the mechanism through which optional, drop-in functionality can be provided to Betty. They are used for a variety of purposes, such as extending the Betty application, or providing additional ancestry data types.

Plugins must extend betty.plugin.Plugin:

from typing import override
from betty.locale.localizable import _
from betty.plugin import Plugin

class MyPlugin(Plugin):
    @override
    @classmethod
    def plugin_id(cls) -> PluginId:
        return "my-plugin"

    @override
    @classmethod
    def plugin_label(cls) -> Localizable:
        return _("My Plugin")

Plugin types

Plugin types are discovered and made available through betty.plugin.PluginRepository implementations. Other than that, there are no guidelines or limitations for what plugins can do, or be used for.

Working with an existing plugin type

The plugin type’s documentation tells you where to find the plugin repository, how to use the plugins, and how to create your own.

Built-in plugin types

The following plugin types are provided by Betty itself:

• CLI commands

• Copyright notices

• Entity types

• Event types

• Extensions

• Genders

• Licenses

• Place types

• Presence roles

• Renderers

• Serialization formats

Creating a new plugin type

If you are developing an API that needs a new plugin type, and you want other developers to be able to define them as entry points, you must create a plugin repository, and you should create an abstract plugin class that extends betty.plugin.Plugin.

Built-in plugin repository types

betty.plugin.entry_point.EntryPointPluginRepository

to discover plugins defined as package entry points.

betty.plugin.lazy.LazyPluginRepositoryBase

to easily build repositories that lazily load their plugins.

betty.plugin.proxy.ProxyPluginRepository

to discover plugins via one or more upstream plugin repositories.

betty.plugin.static.StaticPluginRepository

to discover statically defined plugins.