Use CollectionItem objects

bookwyrm/activitypub/ordered_collection.py

@@ -50,3 +50,27 @@ class OrderedCollectionPage(ActivityObject):
     next: str = None
     prev: str = None
     type: str = "OrderedCollectionPage"
+
+
+@dataclass(init=False)
+class CollectionItem(ActivityObject):
+    """ an item in a collection """
+    actor: str
+    type: str = "CollectionItem"
+
+
+@dataclass(init=False)
+class ListItem(CollectionItem):
+    """ a book on a list """
+    book: str
+    notes: str = None
+    approved: bool = True
+    order: int = None
+    type: str = "ListItem"
+
+
+@dataclass(init=False)
+class ShelfItem(CollectionItem):
+    """ a book on a list """
+    book: str
+    type: str = "ShelfItem"