Piotr added comments

courseware/models.py

@@ -41,19 +41,21 @@ from django.contrib.auth.models import User
 class StudentModule(models.Model):
     # For a homework problem, contains a JSON
     # object consisting of state
+    module_type = models.CharField(max_length=32, choices=MODULE_TYPES, default='problem')
+    module_id = models.CharField(max_length=255) # Filename for homeworks, etc. 
+    student = models.ForeignKey(User)
+
+    class Meta:
+        unique_together = (('student', 'module_id', 'module_type'),)
+
     state = models.TextField(null=True, blank=True)
     grade = models.FloatField(null=True, blank=True)
-    student = models.ForeignKey(User)
     MODULE_TYPES = (('problem','problem'),
                     ('video','video'),
                     ('html','html'),
                     )
-    module_type = models.CharField(max_length=32, choices=MODULE_TYPES, default='problem')
-    module_id = models.CharField(max_length=255) # Filename for homeworks, etc. 
     created = models.DateTimeField(auto_now_add=True)
     modified = models.DateTimeField(auto_now=True)
-    class Meta:
-        unique_together = (('student', 'module_id', 'module_type'),)
 
     def __unicode__(self):
         return self.module_type+'/'+self.student.username+"/"+self.module_id+'/'+str(self.state)[:20]

courseware/module_render.py

@@ -37,6 +37,7 @@ modx_modules={'problem':capa_module.LoncapaModule,
 
 def modx_dispatch(request, module=None, dispatch=None, id=None):
     ''' Generic view for extensions. '''
+    # Grab the student information for the module from the database
     s = StudentModule.objects.filter(module_type=module, 
                                      student=request.user, 
                                      module_id=id)
@@ -52,17 +53,22 @@ def modx_dispatch(request, module=None, dispatch=None, id=None):
 
     id_tag=modx_modules[module].id_attribute
 
+    # Grab the XML corresponding to the request from course.xml
     xml = content_parser.module_xml(content_parser.course_file(request.user), module, id_tag, id)
 
+    # Create the module
     instance=modx_modules[module](xml, 
                                   s.module_id, 
                                   ajax_url=ajax_url, 
                                   state=s.state)
-    html=instance.handle_ajax(dispatch, request.POST)
+    # Let the module handle the AJAX
+    ajax_return=instance.handle_ajax(dispatch, request.POST)
+    # Save the state back to the database
     s.state=instance.get_state()
     s.grade=instance.get_score()['score']
     s.save()
-    return HttpResponse(html)
+    # Return whatever the module wanted to return to the client/caller
+    return HttpResponse(ajax_return)
 
 def vertical_module(request, module):
     ''' Layout module which lays out content vertically.