Plugin registry

src/tixlbase/migrations/0016_event_plugins.py

@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import models, migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('tixlbase', '0015_auto_20141006_2205'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='event',
+            name='plugins',
+            field=models.TextField(blank=True, verbose_name='Plugins', null=True),
+            preserve_default=True,
+        ),
+    ]

src/tixlbase/models.py

@@ -276,6 +276,10 @@ class Event(models.Model):
         verbose_name=_("Last date of payments"),
         help_text=_("The last date any payments are accepted. This has precedence over the number of days configured above.")
     )
+    plugins = models.TextField(
+        null=True, blank=True,
+        verbose_name=_("Plugins"),
+    )
 
     class Meta:
         verbose_name = _("Event")
@@ -291,6 +295,11 @@ class Event(models.Model):
         self.get_cache().clear()
         return obj
 
+    def get_plugins(self):
+        if self.plugins is None:
+            return []
+        return self.plugins.split(",")
+
     def get_date_from_display(self):
         return _date(
             self.date_from,

src/tixlbase/plugins.py

@@ -0,0 +1,17 @@
+from enum import Enum
+
+from django.apps import apps
+
+
+class PluginType(Enum):
+    RESTRICTION = 1
+
+
+def get_all_plugins():
+    plugins = []
+    for app in apps.get_app_configs():
+        if hasattr(app, 'TixlPluginMeta'):
+            meta = app.TixlPluginMeta
+            meta.module = app.name
+            plugins.append(meta)
+    return plugins

src/tixlbase/signals.py

@@ -1,5 +1,39 @@
 import django.dispatch
+from django.apps import apps
+from django.dispatch.dispatcher import NO_RECEIVERS
 
-determine_availability = django.dispatch.Signal(
+
+class EventPluginSignal(django.dispatch.Signal):
+
+    def send(self, sender, **named):
+        """
+        Send signal from sender to all connected receivers that belong to
+        plugins enabled for the given Event.
+
+        sender is required to be an instance of ``tixlbase.models.Event``.
+        """
+        responses = []
+        if not self.receivers or self.sender_receivers_cache.get(sender) is NO_RECEIVERS:
+            return responses
+
+        for receiver in self._live_receivers(sender):
+            # Find the Django application this belongs to
+            searchpath = receiver.__module__
+            app = None
+            while "." in searchpath:
+                try:
+                    if apps.is_installed(searchpath):
+                        app = apps.get_app_config(searchpath.split(".")[-1])
+                except LookupError:
+                    pass
+                searchpath, mod = searchpath.rsplit(".", 1)
+
+            # Only fire receivers from active plugins
+            if app.name in sender.get_plugins():
+                response = receiver(signal=self, sender=sender, **named)
+                responses.append((receiver, response))
+        return responses
+
+determine_availability = EventPluginSignal(
     providing_args=["item", "variations", "context", "cache"]
 )