updated sort params

analytics_data_api/v0/models.py

@@ -256,25 +256,28 @@ class RosterEntry(DocType):
             cohort=None,
             enrollment_mode=None,
             text_search=None,
-            order_by_fields=None,
-            sort_order_directions=None
+            sort_policies=None,
     ):
         """
         Construct a search query for all users in `course_id` and return
         the Search object.
 
-        order_by_fields specifies the fields to order by with the first element of
-        the array as the primary sort.  Similarly, sort_order_directions corresponds
-        to the direction of the sort.  These arrays must be of the same size.
+        sort_policies is an array, where the first element is the primary sort.
+        Elements in the array are dicts with fields: order_by (field to sort by)
+        and sort_order (either 'asc' or 'desc').  Default to 'username' and 'asc'.
 
         Raises `ValueError` if both `segments` and `ignore_segments` are provided.
         """
 
-        if order_by_fields is None:
-            order_by_fields = ['username']
-
-        if sort_order_directions is None:
-            sort_order_directions = ['asc']
+        if sort_policies is None or len(sort_policies) == 0:
+            sort_policies = [{
+                'order_by': None,
+                'sort_order': None
+            }]
+        # set default sort policy to 'username' and 'asc'
+        for field, default in [('order_by', 'username'), ('sort_order', 'asc')]:
+            if sort_policies[0][field] is None:
+                sort_policies[0][field] = default
 
         # Error handling
         if segments and ignore_segments:
@@ -289,25 +292,17 @@ class RosterEntry(DocType):
             'username', 'email', 'discussions_contributed', 'problems_attempted', 'problems_completed',
             'problem_attempts_per_completed', 'attempt_ratio_order', 'videos_viewed'
         )
-        for order_by in order_by_fields:
-            if order_by not in order_by_options:
+        sort_order_options = ('asc', 'desc')
+        for sort_policy in sort_policies:
+            if sort_policy['order_by'] not in order_by_options:
                 raise ValueError("order_by value '{order_by}' must be one of: ({order_by_options})".format(
-                    order_by=order_by, order_by_options=', '.join(order_by_options)
+                    order_by=sort_policy['order_by'], order_by_options=', '.join(order_by_options)
                 ))
-
-        sort_order_options = ('asc', 'desc')
-        for sort_order in sort_order_directions:
-            if sort_order not in sort_order_options:
+            if sort_policy['sort_order'] not in sort_order_options:
                 raise ValueError("sort_order value '{sort_order}' must be one of: ({sort_order_options})".format(
-                    sort_order=sort_order, sort_order_options=', '.join(sort_order_options)
+                    sort_order=sort_policy['sort_order'], sort_order_options=', '.join(sort_order_options)
                 ))
 
-        if len(order_by_fields) != len(sort_order_directions):
-            raise ValueError("The number of items in order_by_fields '{order_by_count}' must equal that of "
-                             "sort_order_directions '{sort_order_count}'".format(
-                                 order_by_count=len(order_by_fields), sort_order_count=len(sort_order_directions)
-                             ))
-
         search = cls.search()
         search.query = Q('bool', must=[Q('term', course_id=course_id)])
 
@@ -326,9 +321,10 @@ class RosterEntry(DocType):
 
         # construct the sort hierarchy
         sort_terms = []
-        for order_by, sort_order in zip(order_by_fields, sort_order_directions):
+        for sort_policy in sort_policies:
+            sort_order = sort_policy['sort_order']
             term = {
-                order_by: {
+                sort_policy['order_by']: {
                     'order': sort_order,
                     'missing': '_last' if sort_order == 'asc' else '_first',  # ordering of missing fields
                 }

analytics_data_api/v0/views/learners.py

@@ -176,17 +176,20 @@ class LearnerListView(CourseViewMixin, generics.ListAPIView):
         query_params = self.request.QUERY_PARAMS
 
         order_by = query_params.get('order_by')
-        order_by_fields = [order_by] if order_by else None
-
         sort_order = query_params.get('sort_order')
-        sort_order_directions = [sort_order] if sort_order else None
+        sort_policies = [{
+            'order_by': order_by,
+            'sort_order': sort_order
+        }]
 
         # Ordering by problem_attempts_per_completed can be ambiguous because
         # values could be infinite (e.g. divide by zero) if no problems were completed.
-        # Instead, secondary sorting by attempt_ratio_order will produce a sensible ordering
+        # Instead, secondary sorting by attempt_ratio_order will produce a sensible ordering.
         if order_by == 'problem_attempts_per_completed':
-            order_by_fields.append('attempt_ratio_order')
-            sort_order_directions.append('asc' if sort_order == 'desc' else 'desc')
+            sort_policies.append({
+                'order_by': 'attempt_ratio_order',
+                'sort_order': 'asc' if sort_order == 'desc' else 'desc'
+            })
 
         params = {
             'segments': split_query_argument(query_params.get('segments')),
@@ -194,8 +197,7 @@ class LearnerListView(CourseViewMixin, generics.ListAPIView):
             'cohort': query_params.get('cohort'),
             'enrollment_mode': query_params.get('enrollment_mode'),
             'text_search': query_params.get('text_search'),
-            'order_by_fields': order_by_fields,
-            'sort_order_directions': sort_order_directions,
+            'sort_policies': sort_policies,
         }
         # Remove None values from `params` so that we don't overwrite default
         # parameter values in `get_users_in_course`.