[core][plugin] Allow blueprints to be set on instance level

This ensures blueprints are read from the plugin instance
instead of the class, allowing custom routes to be added within the
`load()` function.

Signed-off-by: Ferdinand Thiessen <rpm@fthiessen.de>

flaschengeist/app.py

@@ -41,9 +41,14 @@ def load_plugins(app: Flask):
     for plugin in pluginController.get_enabled_plugins():
         logger.debug(f"Searching for enabled plugin {plugin.name}")
         try:
+            # Load class
             cls = plugin.entry_point.load()
-            if hasattr(cls, "blueprint") and cls.blueprint is not None:
-                app.register_blueprint(cls.blueprint)
+            plugin = cls.query.get(plugin.id) if plugin.id is not None else plugin
+            # Custom loading tasks
+            plugin.load()
+            # Register blueprint
+            if hasattr(plugin, "blueprint") and plugin.blueprint is not None:
+                app.register_blueprint(plugin.blueprint)
         except:
             logger.error(
                 f"Plugin {plugin.name} was enabled, but could not be loaded due to an error.",
@@ -51,9 +56,7 @@ def load_plugins(app: Flask):
             )
             continue
         logger.info(f"Loaded plugin: {plugin.name}")
-        app.config["FG_PLUGINS"][plugin.name] = cls.query.get(plugin.id) if plugin.id is not None else plugin
-        app.config["FG_PLUGINS"][plugin.name].load()
-
+        app.config["FG_PLUGINS"][plugin.name] = plugin
 
 def create_app(test_config=None, cli=False):
     app = Flask("flaschengeist")

flaschengeist/plugins/__init__.py

@@ -226,7 +226,7 @@ class AuthPlugin(Plugin):
             password: string
 
         """
-        raise MethodNotAllowed
+        raise NotImplementedError
 
     def delete_user(self, user):
         """If backend is using (writeable) external data, then delete the user from external database.
@@ -235,7 +235,7 @@ class AuthPlugin(Plugin):
             user: User object
 
         """
-        raise MethodNotAllowed
+        raise NotImplementedError
 
     def get_avatar(self, user) -> _Avatar:
         """Retrieve avatar for given user (if supported by auth backend)