Refactor behaviour of "event" mixin:

- Trigger a new background task for each plugin
- Call plugin.process_event
- Plugin class can then decide what to do with the particular event

InvenTree/plugin/builtin/integration/mixins.py

@@ -185,63 +185,19 @@ class EventMixin:
     """
     Mixin that provides support for responding to triggered events.
 
-    Implementing classes must provide a list of tuples,
-    which provide pairs of 'event':'function'
-
-    Notes:
-
-    Events are called by name, and based on the django signal nomenclature,
-    e.g. 'part.pre_save'
-
-    Receiving functions must be prototyped to match the 'event' they receive.
-
-    Example:
-
-    EVENTS = [
-        ('part.pre_save', 'myplugin.functions.do_stuff'),
-        ('build.complete', 'myplugin.functions.process_completed_build'),
-    ]
+    Implementing classes must provide a "process_event" function:
     """
 
-    # Override this in subclass model
-    EVENTS = []
-
+    def process_event(self, event, *args, **kwargs):
+        # Default implementation does not do anything
+        raise NotImplementedError
+    
     class MixinMeta:
         MIXIN_NAME = 'Events'
 
     def __init__(self):
         super().__init__()
-        self.add_mixin('events', 'has_events', __class__)
-        self.events = getattr(self, 'EVENTS', [])
-
-        self.validate_events()
-
-    @property
-    def has_events(self):
-        return bool(self.events) and len(self.events) > 0
-
-    def validate_events(self):
-        """
-        Check that the provided event callbacks are valid
-        """
-
-        if not self.has_events:
-            raise ValueError('EVENTS not defined')
-
-        for pair in self.events:
-            valid = True
-
-            if len(pair) == 2:
-                event = pair[0].strip()
-                func = pair[1].strip()
-
-                if len(event) == 0 or len(func) == 0:
-                    valid = False
-            else:
-                valid = False
-
-            if not valid:
-                raise ValueError("Invalid event callback: " + str(pair))
+        self.add_mixin('events', True, __class__)
 
 
 class UrlsMixin:

InvenTree/plugin/events.py

@@ -30,15 +30,30 @@ def trigger_event(event, *args, **kwargs):
 
     logger.debug(f"Event triggered: '{event}'")
 
-    offload_task(
-        'plugin.events.process_event',
-        event,
-        *args,
-        **kwargs,
-    )
+    # Offload a separate task for each plugin
+    # Determine if there are any plugins which are interested in responding
+    if settings.PLUGIN_TESTING or InvenTreeSetting.get_setting('ENABLE_PLUGINS_EVENTS'):
+
+        for slug, plugin in plugin_registry.plugins.items():
+
+            if plugin.mixin_enabled('events'):
+
+                config = plugin.plugin_config()
+
+                if config and config.active:
+
+                    logger.debug(f"Registering callback for plugin '{slug}'")
+
+                    offload_task(
+                        'plugin.events.process_event',
+                        slug,
+                        event,
+                        *args,
+                        **kwargs
+                    )
 
 
-def process_event(event, *args, **kwargs):
+def process_event(plugin_slug, event, *args, **kwargs):
     """
     Respond to a triggered event.
 
@@ -47,24 +62,8 @@ def process_event(event, *args, **kwargs):
     This function may queue multiple functions to be handled by the background worker.
     """
 
-    logger.info(f"Processing event '{event}'")
+    logger.info(f"Plugin '{plugin_slug}' is processing triggered event '{event}'")
 
-    # Determine if there are any plugins which are interested in responding
-    if settings.PLUGIN_TESTING or InvenTreeSetting.get_setting('ENABLE_PLUGINS_EVENTS'):
+    plugin = plugin_registry.plugins[plugin_slug]
 
-        # Run atomically, to ensure that either *all* tasks are registered, or *none*
-        with transaction.atomic():
-            for slug, callbacks in plugin_registry.mixins_events.items():
-                # slug = plugin slug
-                # callbacks = list of (event, function) tuples
-
-                for _event, _func in callbacks:
-                    if _event == event:
-
-                        logger.info(f"Running task '{_func}' for plugin '{slug}'")
-
-                        offload_task(
-                            _func,
-                            *args,
-                            **kwargs
-                        )
+    plugin.process_event(event, *args, **kwargs)

InvenTree/plugin/integration.py

@@ -176,6 +176,11 @@ class IntegrationPluginBase(MixinBase, plugin.InvenTreePlugin):
         """check if mixin is enabled and ready"""
         if self.mixin(key):
             fnc_name = self._mixins.get(key)
+
+            # Allow for simple case where the mixin is "always" ready
+            if fnc_name == True:
+                return True
+
             return getattr(self, fnc_name, True)
         return False
     # endregion

InvenTree/plugin/registry.py

@@ -59,7 +59,6 @@ class PluginsRegistry:
 
         # mixins
         self.mixins_settings = {}
-        self.mixins_events = {}
 
     # region public plugin functions
     def load_plugins(self):
@@ -267,7 +266,6 @@ class PluginsRegistry:
         logger.info(f'Found {len(plugins)} active plugins')
 
         self.activate_integration_settings(plugins)
-        self.activate_integration_events(plugins)
         self.activate_integration_schedule(plugins)
         self.activate_integration_app(plugins, force_reload=force_reload)
 
@@ -278,7 +276,6 @@ class PluginsRegistry:
 
         self.deactivate_integration_app()
         self.deactivate_integration_schedule()
-        self.deactivate_integration_events()
         self.deactivate_integration_settings()
 
     def activate_integration_settings(self, plugins):
@@ -303,41 +300,6 @@ class PluginsRegistry:
         # clear cache
         self.mixins_settings = {}
 
-    def activate_integration_events(self, plugins):
-        """
-        Activate triggered events mixin for applicable plugins
-        """
-
-        logger.info('Activating plugin events')
-
-        from common.models import InvenTreeSetting
-
-        self.mixins_events = {}
-
-        event_count = 0
-
-        if settings.PLUGIN_TESTING or InvenTreeSetting.get_setting('ENABLE_PLUGINS_EVENTS'):
-
-            for slug, plugin in plugins:
-
-                if plugin.mixin_enabled('events'):
-                    config = plugin.plugin_config()
-
-                    # Only activate events for plugins which are enabled
-                    if config and config.active:
-                        self.mixins_events[slug] = plugin.events
-
-                        event_count += len(plugin.events)
-
-        if event_count > 0:
-            logger.info(f"Registered callbacks for {event_count} events")
-
-    def deactivate_integration_events(self):
-        """
-        Deactivate events for all plugins
-        """
-        self.mixins_events = {}
-
     def activate_integration_schedule(self, plugins):
 
         logger.info('Activating plugin tasks')

InvenTree/plugin/samples/integration/event_sample.py

@@ -6,16 +6,7 @@ from plugin import IntegrationPluginBase
 from plugin.mixins import EventMixin
 
 
-def on_part_saved(*args, **kwargs):
-    """
-    Simple function which responds to a triggered event
-    """
-
-    part_id = kwargs['part_id']
-    print(f"func on_part_saved() - part: {part_id}")
-
-
-class EventPlugin(EventMixin, IntegrationPluginBase):
+class EventPluginSample(EventMixin, IntegrationPluginBase):
     """
     A sample plugin which provides supports for triggered events
     """
@@ -24,6 +15,9 @@ class EventPlugin(EventMixin, IntegrationPluginBase):
     PLUGIN_SLUG = "event"
     PLUGIN_TITLE = "Triggered Events"
 
-    EVENTS = [
-        ('part.saved', 'plugin.samples.integration.event_sample.on_part_saved'),
-    ]
+    def process_event(self, event, *args, **kwargs):
+        """ Custom event processing """
+
+        print(f"Processing triggered event: '{event}'")
+        print("args:", str(args))
+        print("kwargs:", str(kwargs))

InvenTree/plugin/samples/integration/scheduled_task.py

@@ -15,10 +15,6 @@ def print_world():
     print("World")
 
 
-def fail_task():
-    raise ValueError("This task should fail!")
-
-
 class ScheduledTaskPlugin(ScheduleMixin, IntegrationPluginBase):
     """
     A sample plugin which provides support for scheduled tasks
@@ -38,8 +34,4 @@ class ScheduledTaskPlugin(ScheduleMixin, IntegrationPluginBase):
             'func': 'plugin.samples.integration.scheduled_task.print_hello',
             'schedule': 'H',
         },
-        'failure': {
-            'func': 'plugin.samples.integration.scheduled_task.fail_task',
-            'schedule': 'D',
-        },
     }