Implemented headers pagination and conditional pagination mixins.

greenmine/base/api.py

@@ -1,14 +1,16 @@
 # -*- coding: utf-8 -*-
 
-from rest_framework import (
+from rest_framework import viewsets
-    mixins,
+from .pagination import HeadersPaginationMixin, ConditionalPaginationMixin
-    viewsets
-)
 
 
-class ModelCrudViewSet(viewsets.ModelViewSet):
+class ModelCrudViewSet(HeadersPaginationMixin,
+                       ConditionalPaginationMixin,
+                       viewsets.ModelViewSet):
     pass
 
 
-class ModelListViewSet(viewsets.ReadOnlyModelViewSet):
+class ModelListViewSet(HeadersPaginationMixin,
+                       ConditionalPaginationMixin,
+                       viewsets.ReadOnlyModelViewSet):
     pass

greenmine/base/middleware.py

@@ -24,7 +24,8 @@ COORS_ALLOWED_METHODS = getattr(settings, 'COORS_ALLOWED_METHODS',
                             ['POST', 'GET', 'OPTIONS', 'PUT', 'DELETE', 'PATCH'])
 COORS_ALLOWED_HEADERS = getattr(settings, 'COORS_ALLOWED_HEADERS',
                             ['Content-Type', 'X-Requested-With',
-                             'X-Session-Token', 'Accept-Encoding'])
+                             'X-Session-Token', 'Accept-Encoding',
+                             'X-Disable-Pagination'])
 COORS_ALLOWED_CREDENTIALS = getattr(settings, 'COORS_ALLOWED_CREDENTIALS',  True)
 
 

greenmine/base/pagination.py

@@ -0,0 +1,38 @@
+# -*- coding: utf-8 -*-
+
+from rest_framework.templatetags.rest_framework import replace_query_param
+
+
+class ConditionalPaginationMixin(object):
+    def get_paginate_by(self, *args, **kwargs):
+        if "HTTP_X_DISABLE_PAGINATION" in self.request.META:
+            return None
+        return super().get_paginate_by(*args, **kwargs)
+
+
+class HeadersPaginationMixin(object):
+    def paginate_queryset(self, queryset, page_size=None):
+        page = super().paginate_queryset(queryset=queryset, page_size=page_size)
+
+        if page is None:
+            return page
+
+        self.headers["X-Pagination-Total"] = page.paginator.count
+        self.headers["X-Paginated"] = "true"
+
+        if page.has_next():
+            num = page.next_page_number()
+            url = self.request.build_absolute_uri()
+            url = replace_query_param(url, "page", num)
+            self.headers["X-Pagination-Next"] = url
+
+        if page.has_previous():
+            num = page.previous_page_number()
+            url = self.request.build_absolute_uri()
+            url = replace_query_param(url, "page", num)
+            self.headers["X-Pagination-Prev"] = url
+
+        return page
+
+    def get_pagination_serializer(self, page):
+        return self.get_serializer(page.object_list, many=True)