More error handling in connector/books manager

bookwyrm/books_manager.py

@@ -26,7 +26,9 @@ def get_or_create_book(remote_id):
 
     connector = get_or_create_connector(remote_id)
 
+    # raises ConnectorException
     book = connector.get_or_create_book(remote_id)
+    if book:
         load_more_data.delay(book.id)
     return book
 

bookwyrm/connectors/abstract_connector.py

@@ -132,6 +132,9 @@ class AbstractConnector(ABC):
             edition.author_text = work.author_text
             edition.save()
 
+        if not edition:
+            raise ConnectorException('Unable to create book: %s' % remote_id)
+
         return edition
 
 

bookwyrm/connectors/self_connector.py

@@ -50,10 +50,6 @@ class Connector(AbstractConnector):
         )
 
 
-    def get_or_create_book(self, remote_id):
-        ''' this COULD be semi-implemented but I think it shouldn't be used '''
-
-
     def is_work_data(self, data):
         pass