From b67aea22fc707c2b06ee59a49d69aadd3794dda3 Mon Sep 17 00:00:00 2001
From: Mouse Reeve <mousereeve@riseup.net>
Date: Sun, 13 Dec 2020 11:16:12 -0800
Subject: [PATCH] Aggregates (de)serializable model fields

---
 bookwyrm/models/base_model.py | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/bookwyrm/models/base_model.py b/bookwyrm/models/base_model.py
index dd3065c9..d9aafcce 100644
--- a/bookwyrm/models/base_model.py
+++ b/bookwyrm/models/base_model.py
@@ -10,6 +10,8 @@ from Crypto.Hash import SHA256
 from django.core.paginator import Paginator
 from django.db import models
 from django.db.models import Q
+from django.db.models.fields.files import ImageFileDescriptor
+from django.db.models.fields.related_descriptors import ManyToManyDescriptor
 from django.dispatch import receiver
 
 from bookwyrm import activitypub
@@ -68,6 +70,30 @@ class ActivitypubMixin:
     activity_serializer = lambda: {}
     reverse_unfurl = False
 
+    def __init__(self, *args, **kwargs):
+        ''' collect some info on model fields '''
+        self.image_fields = []
+        self.many_to_many_fields = []
+        self.simple_fields = [] # "simple"
+        for field in self._meta.get_fields():
+            if not hasattr(field, 'field_to_activity'):
+                continue
+
+            if isinstance(field, ImageFileDescriptor):
+                self.image_fields.append(field)
+            elif isinstance(field, ManyToManyDescriptor):
+                self.many_to_many_fields.append(field)
+            else:
+                self.simple_fields.append(field)
+
+        self.deserialize_reverse_fields = self.deserialize_reverse_fields \
+                if hasattr(self, 'deserialize_reverse_fields') else []
+        self.serialize_reverse_fields = self.serialize_reverse_fields \
+                if hasattr(self, 'serialize_reverse_fields') else []
+
+        super().__init__(*args, **kwargs)
+
+
     @classmethod
     def find_existing_by_remote_id(cls, remote_id):
         ''' look up a remote id in the db '''