Changed iter method to use cursor pagination API-92

Author: Jian Cheung

clever/__init__.py

@@ -694,30 +694,38 @@ def instance_url(self):
 # Classes of API operations
 
 
+def get_link(response, rel):
+  links = response.get('links', None)
+  for link in links:
+    if link.get('rel', None) == rel:
+      return link.get('uri')
+  return None
+
 class ListableAPIResource(APIResource):
+  ITER_LIMIT = 1000
 
   @classmethod
   def all(cls, auth=None, **params):
     return list(cls.iter(auth, **params))
 
   @classmethod
   def iter(cls, auth=None, **params):
-    for unsupported_param in ['limit', 'page']:
+    for unsupported_param in ['limit', 'page', 'starting_after', 'ending_before']:
       if unsupported_param in params:
         raise CleverError("ListableAPIResource does not support '%s' parameter" %
                           (unsupported_param,))
 
     requestor = APIRequestor(auth)
     url = cls.class_url()
-    params['page'] = 1
-    params['limit'] = 1000
-    done_paginating = False
-    while not done_paginating:
+    params['limit'] = cls.ITER_LIMIT
+
+    while url:
       response, auth = requestor.request('get', url, params)
       for datum in convert_to_clever_object(cls, response, auth):
         yield datum
-      params['page'] += 1
-      done_paginating = len(response['data']) < params['limit']
+      url = get_link(response, 'next')
+      # params already included in url from get_link
+      params = {}
 
 
 class CreatableAPIResource(APIResource):

test/test_clever.py

@@ -76,9 +76,23 @@ def test_iter(self):
     for district in clever.District.iter():
       self.assertTrue(district.id)
 
+  def test_iter_count(self):
+      r = requests.get('https://api.clever.com/v1.1/students?count=true',
+          headers={'Authorization': 'Bearer DEMO_TOKEN'})
+
+      req_count = json.loads(r.text)["count"]
+      iter_count = len([x for x in clever.Student.iter()])
+
+      self.assertTrue(req_count > clever.Student.ITER_LIMIT)
+      self.assertEqual(req_count, iter_count)
+
   def test_unsupported_params(self):
     self.assertRaises(clever.CleverError, lambda: clever.District.all(page=2))
     self.assertRaises(clever.CleverError, lambda: clever.District.all(limit=10))
+    self.assertRaises(clever.CleverError, lambda: clever.District.all(
+        starting_after='4fd43cc56d11340000000005'))
+    self.assertRaises(clever.CleverError, lambda: clever.District.all(
+        ending_before='4fd43cc56d11340000000005'))
     self.assertRaises(clever.CleverError, lambda: clever.District.all(page=2, limit=10))
 
   def test_unicode(self):