WIP: adding deletions of relationships to edit pages

web/app/resources.py

     flash('Successfully deleted!')
 
 # function to delete a single relationship
-#def delete_relationship(first_resource_id, second_resource_id):
-    #relationship_id = Relationship.query.filter_by(first_resource_id=first_resource_id).first()
-    #return relationship_id['id']
-    #deletion = Relationship.query.get(relationship_id)
-    #db.session.delete(deletion)
-    #db.session.commit()
+def delete_relationship(first_resource_id, second_resource_id):
+    relation = Relationship.query.filter_by(first_resource_id=first_resource_id).first()
+    deletion = Relationship.query.get(relation.id)
+    db.session.delete(deletion)
+    db.session.commit()

web/app/templates/edit.html

         <select name="linked_resources" id="linked_resources" aria-label="Linked resources" class="selectpicker" data-live-search="true" multiple>
           {% for resource_dropdown in resource_dropdown %}
             {% if resource_dropdown['type'] != 'tool' %}
-              {% if resource_dropdown in links %}
+              {% if links and resource_dropdown in links %}
                 <option value="{{ resource_dropdown['id'] }}" selected>{{ resource_dropdown['name'] }}</option>
               {% else %}
                 <option value="{{ resource_dropdown['id'] }}">{{ resource_dropdown['name'] }}</option>

web/app/tool.py

             if linked_resources:
                 for linked_resource in linked_resources:
                     link = Resource.query.get(linked_resource)
-                    if link not in links:
+                    if links and link not in links:
                         add_linked_resource(tool_id, linked_resource)
-            #if remove_linked_resources:
-            #    for remove_linked_resource in remove_linked_resources:
-            #        delete_relationship(tool_id, remove_linked_resource)
+                    elif not links:
+                        add_linked_resource(tool_id, linked_resource)
+            if remove_linked_resources:
+                for remove_linked_resource in remove_linked_resources:
+                    delete_relationship(tool_id, remove_linked_resource)
             return redirect(url_for('tool.get_tools'))
 
     return render_template('edit.html', resource=tool, resource_dropdown=resource_dropdown, links=links)