magic-removal: Updated django.core.paginator to work with QuerySet objects instead of Managers/Models

git-svn-id: http://code.djangoproject.com/svn/django/branches/magic-removal@2212 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/core/paginator.py

@@ -6,24 +6,17 @@ class InvalidPage(Exception):
 
 class ObjectPaginator:
     """
-    This class makes pagination easy. Feed it a manager (an object with
-    get_count() and get_list() methods) or a model which has a default manager,
-    and a dictionary of arguments to be passed to those methods, plus the 
-    number of objects you want on each page. Then read the hits and pages 
-    properties to see how many pages it involves. Call get_page with a page 
-    number (starting at 0) to get back a list of objects for that page.
-    
+    This class makes pagination easy. Feed it a QuerySet, plus the number of
+    objects you want on each page. Then read the hits and pages properties to
+    see how many pages it involves. Call get_page with a page number (starting
+    at 0) to get back a list of objects for that page.
+
     Finally, check if a page number has a next/prev page using
     has_next_page(page_number) and has_previous_page(page_number).
     """
-    def __init__(self, manager_or_model, args, num_per_page, count_method='count', list_method='all'):
-        if hasattr(manager_or_model, '_default_manager'):
-            manager = manager_or_model._default_manager
-        else:
-            manager = manager_or_model
-        self.manager, self.args = manager, args
+    def __init__(self, query_set, num_per_page):
+        self.query_set = query_set
         self.num_per_page = num_per_page
-        self.count_method, self.list_method = count_method, list_method
         self._hits, self._pages = None, None
         self._has_next = {} # Caches page_number -> has_next_boolean
 
@@ -34,14 +27,17 @@ class ObjectPaginator:
             raise InvalidPage
         if page_number < 0:
             raise InvalidPage
-        args = copy(self.args)
-        args['offset'] = page_number * self.num_per_page
+
         # Retrieve one extra record, and check for the existence of that extra
         # record to determine whether there's a next page.
-        args['limit'] = self.num_per_page + 1
-        object_list = getattr(self.manager, self.list_method)(**args)
+        limit = self.num_per_page + 1
+        offset = page_number * self.num_per_page
+
+        object_list = list(self.query_set[offset:offset+limit])
+
         if not object_list:
             raise InvalidPage
+
         self._has_next[page_number] = (len(object_list) > self.num_per_page)
         return object_list[:self.num_per_page]
 
@@ -49,11 +45,8 @@ class ObjectPaginator:
         "Does page $page_number have a 'next' page?"
         if not self._has_next.has_key(page_number):
             if self._pages is None:
-                args = copy(self.args)
-                args['offset'] = (page_number + 1) * self.num_per_page
-                args['limit'] = 1
-                object_list = getattr(self.manager, self.list_method)(**args)
-                self._has_next[page_number] = (object_list != [])
+                offset = (page_number + 1) * self.num_per_page
+                self._has_next[page_number] = len(self.query_set[offset:offset+1]) > 0
             else:
                 self._has_next[page_number] = page_number < (self.pages - 1)
         return self._has_next[page_number]
@@ -63,12 +56,7 @@ class ObjectPaginator:
 
     def _get_hits(self):
         if self._hits is None:
-            order_args = copy(self.args)
-            if order_args.has_key('order_by'):
-                del order_args['order_by']
-            if order_args.has_key('select_related'):
-                del order_args['select_related']
-            self._hits = getattr(self.manager, self.count_method)(**order_args)
+            self._hits = self.query_set.count()
         return self._hits
 
     def _get_pages(self):