some parts of product - fix custom pagination - add id to pages list

apps/core/error_handler.py

@@ -7,8 +7,9 @@ def custom_exception_handler(exc, context):
 
     if response is not None:
         response.data['status_code'] = response.status_code
-        response.data['message'] = response.data.get('detail', str(exc))
-        del response.data['detail']
+        if response.data.get('detail'):
+            response.data['message'] = response.data.get('detail', str(exc))
+            del response.data['detail']
     else:
         response = JsonResponse({'message': str(exc), 'status_code': 500})
         response.status_code = 500

apps/core/pagination.py

@@ -0,0 +1,7 @@
+from rest_framework.pagination import PageNumberPagination
+
+
+class CustomPageNumberPagination(PageNumberPagination):
+    page_size = 20  # default
+    page_size_query_param = 'page_size'  # set from client
+    max_page_size = 100  # maximum items to show