app/django/core/paginator.py
changeset 323 ff1a9aa48cfd
parent 54 03e267d67478
--- a/app/django/core/paginator.py	Tue Oct 14 12:36:55 2008 +0000
+++ b/app/django/core/paginator.py	Tue Oct 14 16:00:59 2008 +0000
@@ -1,6 +1,14 @@
+from math import ceil
+
 class InvalidPage(Exception):
     pass
 
+class PageNotAnInteger(InvalidPage):
+    pass
+
+class EmptyPage(InvalidPage):
+    pass
+
 class Paginator(object):
     def __init__(self, object_list, per_page, orphans=0, allow_empty_first_page=True):
         self.object_list = object_list
@@ -14,14 +22,14 @@
         try:
             number = int(number)
         except ValueError:
-            raise InvalidPage('That page number is not an integer')
+            raise PageNotAnInteger('That page number is not an integer')
         if number < 1:
-            raise InvalidPage('That page number is less than 1')
+            raise EmptyPage('That page number is less than 1')
         if number > self.num_pages:
             if number == 1 and self.allow_empty_first_page:
                 pass
             else:
-                raise InvalidPage('That page contains no results')
+                raise EmptyPage('That page contains no results')
         return number
 
     def page(self, number):
@@ -36,20 +44,24 @@
     def _get_count(self):
         "Returns the total number of objects, across all pages."
         if self._count is None:
-            self._count = len(self.object_list)
+            try:
+                self._count = self.object_list.count()
+            except (AttributeError, TypeError):
+                # AttributeError if object_list has no count() method.
+                # TypeError if object_list.count() requires arguments
+                # (i.e. is of type list).
+                self._count = len(self.object_list)
         return self._count
     count = property(_get_count)
 
     def _get_num_pages(self):
         "Returns the total number of pages."
         if self._num_pages is None:
-            hits = self.count - 1 - self.orphans
-            if hits < 1:
-                hits = 0
-            if hits == 0 and not self.allow_empty_first_page:
+            if self.count == 0 and not self.allow_empty_first_page:
                 self._num_pages = 0
             else:
-                self._num_pages = hits // self.per_page + 1
+                hits = max(1, self.count - self.orphans)
+                self._num_pages = int(ceil(hits / float(self.per_page)))
         return self._num_pages
     num_pages = property(_get_num_pages)
 
@@ -61,15 +73,7 @@
         return range(1, self.num_pages + 1)
     page_range = property(_get_page_range)
 
-class QuerySetPaginator(Paginator):
-    """
-    Like Paginator, but works on QuerySets.
-    """
-    def _get_count(self):
-        if self._count is None:
-            self._count = self.object_list.count()
-        return self._count
-    count = property(_get_count)
+QuerySetPaginator = Paginator # For backwards-compatibility.
 
 class Page(object):
     def __init__(self, object_list, number, paginator):
@@ -100,6 +104,9 @@
         Returns the 1-based index of the first object on this page,
         relative to total objects in the paginator.
         """
+        # Special case, return zero if no items.
+        if self.paginator.count == 0:
+            return 0
         return (self.paginator.per_page * (self.number - 1)) + 1
 
     def end_index(self):
@@ -107,79 +114,7 @@
         Returns the 1-based index of the last object on this page,
         relative to total objects found (hits).
         """
+        # Special case for the last page because there can be orphans.
         if self.number == self.paginator.num_pages:
             return self.paginator.count
         return self.number * self.paginator.per_page
-
-class ObjectPaginator(Paginator):
-    """
-    Legacy ObjectPaginator class, for backwards compatibility.
-
-    Note that each method on this class that takes page_number expects a
-    zero-based page number, whereas the new API (Paginator/Page) uses one-based
-    page numbers.
-    """
-    def __init__(self, query_set, num_per_page, orphans=0):
-        Paginator.__init__(self, query_set, num_per_page, orphans)
-        import warnings
-        warnings.warn("The ObjectPaginator is deprecated. Use django.core.paginator.Paginator instead.", DeprecationWarning)
-
-        # Keep these attributes around for backwards compatibility.
-        self.query_set = query_set
-        self.num_per_page = num_per_page
-        self._hits = self._pages = None
-
-    def validate_page_number(self, page_number):
-        try:
-            page_number = int(page_number) + 1
-        except ValueError:
-            raise InvalidPage
-        return self.validate_number(page_number)
-
-    def get_page(self, page_number):
-        try:
-            page_number = int(page_number) + 1
-        except ValueError:
-            raise InvalidPage
-        return self.page(page_number).object_list
-
-    def has_next_page(self, page_number):
-        return page_number < self.pages - 1
-
-    def has_previous_page(self, page_number):
-        return page_number > 0
-
-    def first_on_page(self, page_number):
-        """
-        Returns the 1-based index of the first object on the given page,
-        relative to total objects found (hits).
-        """
-        page_number = self.validate_page_number(page_number)
-        return (self.num_per_page * (page_number - 1)) + 1
-
-    def last_on_page(self, page_number):
-        """
-        Returns the 1-based index of the last object on the given page,
-        relative to total objects found (hits).
-        """
-        page_number = self.validate_page_number(page_number)
-        if page_number == self.num_pages:
-            return self.count
-        return page_number * self.num_per_page
-
-    def _get_count(self):
-        # The old API allowed for self.object_list to be either a QuerySet or a
-        # list. Here, we handle both.
-        if self._count is None:
-            try:
-                self._count = self.object_list.count()
-            except TypeError:
-                self._count = len(self.object_list)
-        return self._count
-    count = property(_get_count)
-
-    # The old API called it "hits" instead of "count".
-    hits = count
-
-    # The old API called it "pages" instead of "num_pages".
-    pages = Paginator.num_pages