Fix relation between MultipleChoiceOption and FeedbackOption

When a MultipleChoiceOption is created via the API call PUT /mult-choice, a new FeedbackOption is now automatically inserted into the database that links to the same problem as the MultipleChoiceOption.

The response of PUT /mult-choice will now contain an mc_id that shows the ID of the new MultipleChoiceQuestion and a feedback_id with the ID of the new FeedbackOption.

The relation between MultipleChoiceOption and Problem is now removed. A new relation from FeedbackOption to MultipleChoiceOption is created. However, it is still possible to use problem.mc_options with a hybrid attribute that essentially runs a query in the background.

TODO:

• Ensure that if a FeedbackOption is deleted, the related MultipleChoiceOption is also deleted.

Closes #35 (closed) and #36 (closed).

zesje/database.py

@@ -110,6 +110,7 @@ class FeedbackOption(db.Model):
     text = Column(Text, nullable=False)
     description = Column(Text, nullable=True)
     score = Column(Integer, nullable=True)
+    mc_option = db.relationship('MultipleChoiceOption', backref='feedback', lazy=True)
 
 
 # Table for many to many relationship of FeedbackOption and Solution
@@ -166,7 +167,6 @@ class MultipleChoiceOption(Widget):
     id = Column(Integer, ForeignKey('widget.id'), primary_key=True, autoincrement=True)
 
     label = Column(String, nullable=True)
-    problem_id = Column(Integer, ForeignKey('problem.id'), nullable=False)
     feedback_id = Column(Integer, ForeignKey('feedback_option.id'), nullable=False)
 
     __mapper_args__ = {