Improve sanity of custom SQL in Ajax scheduler json view

Fixes #1698 by avoiding the cast to a string, since what we really
wanted was a list of ints anyway.

Author: mgersh

esp/esp/program/modules/handlers/jsondatamodule.py

@@ -136,12 +136,9 @@ def resource_types(prog):
     @needs_admin
     @cached_module_view
     def schedule_assignments(prog):
-        data = ClassSection.objects.filter(status__gte=0, parent_class__status__gte=0, parent_class__parent_program=prog).select_related('resourceassignment__resource__name', 'resourceassignment__resource__event').extra({'timeslots': 'SELECT string_agg(to_char(resources_resource.event_id, \'999\'), \',\') FROM resources_resource, resources_resourceassignment WHERE resources_resource.id = resources_resourceassignment.resource_id AND resources_resourceassignment.target_id = program_classsection.id'}).values('id', 'resourceassignment__resource__name', 'timeslots').distinct()
-        #   Convert comma-separated timeslot IDs to lists
+        data = ClassSection.objects.filter(status__gte=0, parent_class__status__gte=0, parent_class__parent_program=prog).select_related('resourceassignment__resource__name', 'resourceassignment__resource__event').extra({'timeslots': 'SELECT array_agg(resources_resource.event_id) FROM resources_resource, resources_resourceassignment WHERE resources_resource.id = resources_resourceassignment.resource_id AND resources_resourceassignment.target_id = program_classsection.id'}).values('id', 'resourceassignment__resource__name', 'timeslots').distinct()
         for i in range(len(data)):
-            if data[i]['timeslots']:
-                data[i]['timeslots'] = [int(x) for x in data[i]['timeslots'].strip().split(',')]
-            else:
+            if not data[i]['timeslots']:
                 data[i]['timeslots'] = []
         return {'schedule_assignments': list(data)}
     schedule_assignments.method.cached_function.depend_on_row(ClassSection, lambda sec: {'prog': sec.parent_class.parent_program})