Starts getting reverse fields working for deserialization

also fixes the fields on the image model and runs a long overdue
migration

bookwyrm/models/attachment.py

@@ -9,7 +9,7 @@ from . import fields
 
 class Attachment(ActivitypubMixin, BookWyrmModel):
     ''' an image (or, in the future, video etc) associated with a status '''
-    status = fields.ForeignKey(
+    status = models.ForeignKey(
         'Status',
         on_delete=models.CASCADE,
         related_name='attachments',
@@ -23,7 +23,8 @@ class Attachment(ActivitypubMixin, BookWyrmModel):
 
 class Image(Attachment):
     ''' an image attachment '''
-    image = fields.ImageField(upload_to='status/', null=True, blank=True)
-    caption = fields.TextField(null=True, blank=True)
+    image = fields.ImageField(
+        upload_to='status/', null=True, blank=True, activitypub_field='url')
+    caption = fields.TextField(null=True, blank=True, activitypub_field='name')
 
     activity_serializer = activitypub.Image

bookwyrm/models/base_model.py

@@ -83,9 +83,11 @@ class ActivitypubMixin:
 
         if hasattr(self, 'serialize_reverse_fields'):
             # for example, editions of a work
-            for field_name in self.serialize_reverse_fields:
-                related_field = getattr(self, field_name)
-                activity[field_name] = unfurl_related_field(related_field)
+            for model_field_name, activity_field_name in \
+                    self.serialize_reverse_fields:
+                related_field = getattr(self, model_field_name)
+                activity[activity_field_name] = \
+                        unfurl_related_field(related_field)
 
         if not activity.get('id'):
             activity['id'] = self.get_remote_id()

bookwyrm/models/book.py

@@ -96,7 +96,8 @@ class Work(OrderedCollectionPageMixin, Book):
         return self.default_edition or self.editions.first()
 
     activity_serializer = activitypub.Work
-    serialize_reverse_fields = ['editions']
+    serialize_reverse_fields = [('editions', 'editions')]
+    deserialize_reverse_fields = [('editions', 'editions')]
 
 
 class Edition(Book):

bookwyrm/models/status.py

@@ -45,7 +45,8 @@ class Status(OrderedCollectionPageMixin, BookWyrmModel):
     objects = InheritanceManager()
 
     activity_serializer = activitypub.Note
-    serialize_reverse_fields = ['attachments']
+    serialize_reverse_fields = [('attachments', 'attachment')]
+    deserialize_reverse_fields = [('attachments', 'attachment')]
 
     #----- replies collection activitypub ----#
     @classmethod

bookwyrm/models/user.py

@@ -166,7 +166,7 @@ class KeyPair(ActivitypubMixin, BookWyrmModel):
         blank=True, null=True, activitypub_field='publicKeyPem')
 
     activity_serializer = activitypub.PublicKey
-    serialize_reverse_fields = ['owner']
+    serialize_reverse_fields = [('owner', 'owner')]
 
     def get_remote_id(self):
         # self.owner is set by the OneToOneField on User