Exposing your plugin types

The Plugin module describes a format for telling other projects about the plugin types your module provides. This is useful if those projects provide generic features for any plugin type, such as Drupal core's cache clearing mechanisms, or the Plugin module's plugin field type, which can store instances of plugins of any type.

Exposing plugin types

Modules can expose their plugin types through $module.plugin_type.yml files in their root folders, where $module is the name of the module itself. The files' contents are objects. Top-level keys are plugin type IDs (strings), and the values are objects. The only required object property is class, which must be the fully qualified name of a class that implements \Drupal\plugin\PluginType\PluginTypeInterface, or be left empty to default to \Drupal\plugin\PluginType\PluginType. All other properties depend on the class, but the default class takes the following:

• label (required): the human-readable US English plugin type label.
• description (optional): the human-readable US English plugin description
• plugin_manager_service_id (required): the ID of the plugin type's plugin manager in the service container
• plugin_definition_decorator_class (required) the fully qualified name of a class that implements \Drupal\plugin\PluginDefinition\PluginDefinitionDecoratorInterface if the original plugin definitions do not implement \Drupal\plugin\PluginDefinition\PluginDefinitionInterface. Most plugin types use array definitions, and they can use \Drupal\plugin\PluginDefinition\ArrayPluginDefinitionDecorator here.
• operations_provider_class (optional): the fully qualified name of a class that implements \Drupal\plugin\PluginType\PluginTypeOperationsProviderInterface. Defaults to \Drupal\plugin\PluginType\DefaultPluginTypeOperationsProvider

Example:

payment_method:
  label: Payment method
  plugin_manager_service_id: plugin.manager.payment.method
  plugin_definition_decorator_class: \Drupal\plugin\PluginDefinition\ArrayPluginDefinitionDecorator
  operations_provider_class: \Drupal\payment\Plugin\Payment\Method\PaymentMethodOperationsProvider

Exposing plugin configuration schemas

Configuration schemas are used to inspect module's configuration, and to provide features like configuration translation. If you expose a plugin type, a schema for its configuration MAY be provided. Not providing a schema will simply mean that any configuration of plugins of your type that is stored by other modules will not benefit from the aforementioned features.
If a schema is provided, its name MUST be like plugin.plugin_configuration.$plugin_type_id.$plugin_id, where $plugin_type_id is the plugin type ID as specified in $module.plugin_type.yml and $plugin_id is the ID of a specific plugin.
An example for a plugin type called foo and a plugin with ID bar:

plugin.plugin_configuration.foo.bar:
  type: mapping
  mapping:
    label:
      label: Label
      type: label
    do_something:
      label: Do something useful
      type: boolean

See #2629640: Configuration schema aliases for exposing existing schemas using this format.