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).

migrations/versions/b46a2994605b_.py

@@ -21,11 +21,9 @@ def upgrade():
     op.create_table('mc_option',
                     sa.Column('id', sa.Integer(), autoincrement=True, nullable=False),
                     sa.Column('label', sa.String(), nullable=True),
-                    sa.Column('problem_id', sa.Integer(), nullable=False),
                     sa.Column('feedback_id', sa.Integer(), nullable=False),
                     sa.ForeignKeyConstraint(['feedback_id'], ['feedback_option.id'], ),
                     sa.ForeignKeyConstraint(['id'], ['widget.id'], ),
-                    sa.ForeignKeyConstraint(['problem_id'], ['problem.id'], ),
                     sa.PrimaryKeyConstraint('id')
                     )
     # ### end Alembic commands ###