Pagination Helper

flask_pymongo/__init__.py

@@ -40,7 +40,10 @@
 
 from flask_pymongo.wrappers import MongoClient
 from flask_pymongo.wrappers import MongoReplicaSetClient
+from flask_pymongo.helpers import paginate
 
+# Monkey patch Cursor to add paginate
+setattr(pymongo.cursor.Cursor, 'paginate', paginate)
 
 
 PRIMARY = pymongo.ReadPreference.PRIMARY

flask_pymongo/helpers.py

@@ -0,0 +1,52 @@
+# Copyright (c) 2013, Lorenzo Masini <[email protected]>
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#
+# * Redistributions of source code must retain the above copyright notice,
+#   this list of conditions and the following disclaimer.
+#
+# * Redistributions in binary form must reproduce the above copyright notice,
+#   this list of conditions and the following disclaimer in the documentation
+#   and/or other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+
+class Paginator(object):
+    def __init__(self, cursor, page, per_page):
+        self.cursor = cursor
+        self.page = page
+        self.per_page = per_page
+
+    def num_pages(self):
+        count = self.cursor.count()
+        pages = count / self.per_page
+        if count % self.per_page:
+            pages += 1
+        return pages
+
+    def has_prev(self):
+        return self.page > 0
+
+    def has_next(self):
+        return self.page < self.num_pages() - 1
+
+    def entries(self):
+        start = self.page * self.per_page
+        end = start + self.per_page
+        return self.cursor[start:end]
+
+def paginate(cursor, page=0, per_page=10):
+    return Paginator(cursor, page, per_page)
+