move parent[] to parent as the array was never needed, removed some dead code, clarified another example of new BUG-46

main.py

@@ -152,7 +152,7 @@ class Book(db.Model):
     modified = db.Column(db.DateTime)
 
     # take actual parent book as there is no real associated sub_book_num data and can just use it
-    parent = db.relationship('Book', secondary=Book_Sub_Book_Link.__table__, primaryjoin="Book.id==Book_Sub_Book_Link.sub_book_id", secondaryjoin="Book.id==Book_Sub_Book_Link.book_id" )
+    parent = db.relationship('Book', secondary=Book_Sub_Book_Link.__table__, primaryjoin="Book.id==Book_Sub_Book_Link.sub_book_id", secondaryjoin="Book.id==Book_Sub_Book_Link.book_id", uselist=False )
     # but use child_ref as sub_book_num is per book, and I can't connect an empty array of sub_book_nums to a child book array in "child"
     child_ref = db.relationship('Book_Sub_Book_Link', secondary=Book_Sub_Book_Link.__table__, primaryjoin="Book.id==Book_Sub_Book_Link.book_id", secondaryjoin="Book.id==Book_Sub_Book_Link.sub_book_id", order_by="Book_Sub_Book_Link.sub_book_num", overlaps="parent" )
 
@@ -166,7 +166,7 @@ class Book(db.Model):
             return False
 
     def IsChild(self):
-        if len(self.parent):
+        if self.parent:
             return True
         else:
             return False
@@ -444,7 +444,7 @@ def CalcMoveForBookInSeries( id, bid, dir ):
 
         # if book2 is a sub book, then we need its parent as book2 instead, as we have to move the whole book as one
         if book2.IsChild():
-           book2 = Book.query.get( book2.parent[0].id )
+           book2 = Book.query.get( book2.parent.id )
 
         # By here: book1 is parent or normal book we are swapping with book2 which is parent or normal book
         b1_numsb = book1.NumSubBooks()
@@ -598,7 +598,7 @@ def RemoveDuplicateSeriesInForm( book, request ):
 
             # add the contains (null for book_num) bsl for the parent book
             if book.IsChild():
-                parent_bsl=Book_Series_Link( book_id=book.parent[0].id, series_id=request.form[f'bsl-series_id-{cnt}'] )
+                parent_bsl=Book_Series_Link( book_id=book.parent.id, series_id=request.form[f'bsl-series_id-{cnt}'] )
                 db.session.add(parent_bsl)
 
             db.session.add(newbsl)
@@ -735,7 +735,7 @@ def DeleteBook(id):
         st.SetMessage("Deleted {}".format(book.title) )
         pid = 0
         if book.IsChild():
-            pid = book.parent[0].id
+            pid = book.parent.id
         try:
             ClearAuthorsForBook(book.id)
             db.session.delete(book)
@@ -828,30 +828,14 @@ def book(id):
                 CheckSeriesChange={'type':'parent', 'pid': book.id, 'bid': book.id, 'removing_series': removing_series }
             # saving a child / sub_book, consider series
             if book.IsChild() and len(removing_series) > 0:
-                CheckSeriesChange={'type':'child', 'pid': book.parent[0].id, 'bid': book.id, 'removing_series': removing_series }
+                CheckSeriesChange={'type':'child', 'pid': book.parent.id, 'bid': book.id, 'removing_series': removing_series }
             else:
                 # either we are a normal book (no parent/child), OR not removing a series, might be adding though, so easiest is to
                 # delete all bsls and then add them back based on the request.form
                 Book_Series_Link.query.filter(Book_Series_Link.book_id == book.id ).delete()
                 if book.IsChild():
-                    Book_Series_Link.query.filter(Book_Series_Link.book_id == book.parent[0].id ).delete()
+                    Book_Series_Link.query.filter(Book_Series_Link.book_id == book.parent.id ).delete()
 
-#                cnt=1
-#                for field in request.form:
-#                    if 'bsl-book_id-' in field and field != 'bsl-book_id-NUM':
-#                        cnt=int(re.findall( '\d+', field )[0])
-#                        if book.IsParent():
-#                            newbsl=Book_Series_Link( book_id=request.form[f'bsl-book_id-{cnt}'],
-#                                series_id=request.form[f'bsl-series_id-{cnt}'] )
-#                        else:
-#                            newbsl=Book_Series_Link( book_id=request.form[f'bsl-book_id-{cnt}'],
-#                                series_id=request.form[f'bsl-series_id-{cnt}'], 
-#                                book_num=request.form[f'bsl-book_num-{cnt}'] )
-#                            # add the contains (null for book_num) bsl for the parent book
-#                            if book.IsChild():
-#                                parent_bsl=Book_Series_Link( book_id=book.parent[0].id, series_id=request.form[f'bsl-series_id-{cnt}'] )
-#                                db.session.add(parent_bsl)
-#                        db.session.add(newbsl)
             message=RemoveDuplicateSeriesInForm( book, request )
             db.session.commit()
 
@@ -985,10 +969,10 @@ def OrderBooks(books):
                 if tmp_b.IsChild():
                     # this child book wont be in books, but its parent will -> use it instead
                     # mark parent from books so we dont process it twice
-                    if tmp_b.parent[0].id not in processed:
+                    if tmp_b.parent.id not in processed:
                         processed.append(tmp_b.id)
-                        processed.append(tmp_b.parent[0].id)
-                        ordered_books.append(tmp_b.parent[0])
+                        processed.append(tmp_b.parent.id)
+                        ordered_books.append(tmp_b.parent)
                 else:
                     if tmp_b.id not in processed:
                         ordered_books.append(tmp_b)