Feature: Add naive plugin support for pinry

pinry_plugins/builder/_loader.py

@@ -0,0 +1,63 @@
+import logging
+
+from django.dispatch import receiver
+from django.utils.module_loading import import_string
+from django.conf import settings
+from django.db import models
+
+from core.models import Image
+from django_images.models import Thumbnail
+
+_plugins = getattr(settings, "ENABLED_PLUGINS", [])
+_plugin_instances = []
+
+
+def _load_plugins():
+    for plugin_path in _plugins:
+        plugin_cls = import_string(plugin_path)
+        _plugin_instances.append(plugin_cls())
+
+
+@receiver(models.signals.pre_save, sender=Image)
+def process_image_pre_creation(sender, instance: Image, **kwargs):
+    # FIXME(winkidney): May have issue on determining if it
+    #  is created or not
+    if instance.pk is not None:
+        return
+    for plugin in _plugin_instances:
+        process_fn = getattr(plugin, "process_image_pre_creation")
+        try:
+            process_fn(
+                django_settings=settings,
+                image_instance=instance,
+            )
+        except Exception:
+            logging.exception(
+                "Error occurs while trying to access plugin's pin_pre_save "
+                "for plugin %s" % plugin
+            )
+
+
+@receiver(models.signals.pre_save, sender=Thumbnail)
+def process_thumbnail_pre_creation(sender, instance: Thumbnail, **kwargs):
+    # FIXME(winkidney): May have issue on determining if it
+    #  is created or not
+    if instance.pk is not None:
+        return
+
+    for plugin in _plugin_instances:
+        process_fn = getattr(plugin, "process_thumbnail_pre_creation")
+        try:
+            process_fn(
+                django_settings=settings,
+                thumbnail_instance=instance,
+            )
+        except Exception:
+            logging.exception(
+                "Error occurs while trying to access plugin's process_thumbnail_pre_creation "
+                "for plugin %s" % plugin
+            )
+
+
+def init():
+    _load_plugins()