From 07575eb46cf43c63f4ff52a1e1e407469d68dfac Mon Sep 17 00:00:00 2001
From: homm <homm86@gmail.com>
Date: Fri, 12 Jun 2015 18:23:12 +0300
Subject: [PATCH 1/8] make PageSizePaginationMixin from all this page_size
 stuff

---
 rest_framework/pagination.py | 53 +++++++++++++++++++-----------------
 1 file changed, 28 insertions(+), 25 deletions(-)

diff --git a/rest_framework/pagination.py b/rest_framework/pagination.py
index 5938063af..9ba4b2c4d 100644
--- a/rest_framework/pagination.py
+++ b/rest_framework/pagination.py
@@ -201,7 +201,34 @@ class BasePagination(object):
         raise NotImplementedError('to_html() must be implemented to display page controls.')
 
 
-class PageNumberPagination(BasePagination):
+class PageSizePaginationMixin(object):
+    # The default page size.
+    # Defaults to `None`, meaning pagination is disabled.
+    page_size = api_settings.PAGE_SIZE
+
+    # Set to an integer to limit the maximum page size the client may request.
+    # Only relevant if 'page_size_query_param' has also been set.
+    max_page_size = None
+
+    # Client can control the page size using this query parameter.
+    # Default is 'None'. Set to eg 'page_size' to enable usage.
+    page_size_query_param = None
+
+    def get_page_size(self, request):
+        if self.page_size_query_param:
+            try:
+                return _positive_int(
+                    request.query_params[self.page_size_query_param],
+                    strict=True,
+                    cutoff=self.max_page_size
+                )
+            except (KeyError, ValueError):
+                pass
+
+        return self.page_size
+
+
+class PageNumberPagination(PageSizePaginationMixin, BasePagination):
     """
     A simple page number based style that supports page numbers as
     query parameters. For example:
@@ -209,21 +236,10 @@ class PageNumberPagination(BasePagination):
     http://api.example.org/accounts/?page=4
     http://api.example.org/accounts/?page=4&page_size=100
     """
-    # The default page size.
-    # Defaults to `None`, meaning pagination is disabled.
-    page_size = api_settings.PAGE_SIZE
 
     # Client can control the page using this query parameter.
     page_query_param = 'page'
 
-    # Client can control the page size using this query parameter.
-    # Default is 'None'. Set to eg 'page_size' to enable usage.
-    page_size_query_param = None
-
-    # Set to an integer to limit the maximum page size the client may request.
-    # Only relevant if 'page_size_query_param' has also been set.
-    max_page_size = None
-
     last_page_strings = ('last',)
 
     template = 'rest_framework/pagination/numbers.html'
@@ -318,19 +334,6 @@ class PageNumberPagination(BasePagination):
             ('results', data)
         ]))
 
-    def get_page_size(self, request):
-        if self.page_size_query_param:
-            try:
-                return _positive_int(
-                    request.query_params[self.page_size_query_param],
-                    strict=True,
-                    cutoff=self.max_page_size
-                )
-            except (KeyError, ValueError):
-                pass
-
-        return self.page_size
-
     def get_next_link(self):
         if not self.page.has_next():
             return None

From 02707aa92e75fe501ed2cc01471181b5903063cc Mon Sep 17 00:00:00 2001
From: homm <homm86@gmail.com>
Date: Fri, 12 Jun 2015 18:57:46 +0300
Subject: [PATCH 2/8] use PageSizePaginationMixin for CursorPagination tests
 for custom page_size in CursorPagination

---
 rest_framework/pagination.py | 10 +++++-----
 tests/test_pagination.py     | 20 ++++++++++++++++++++
 2 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/rest_framework/pagination.py b/rest_framework/pagination.py
index 9ba4b2c4d..d5718dfc3 100644
--- a/rest_framework/pagination.py
+++ b/rest_framework/pagination.py
@@ -487,20 +487,20 @@ class LimitOffsetPagination(BasePagination):
         return template.render(context)
 
 
-class CursorPagination(BasePagination):
+class CursorPagination(PageSizePaginationMixin, BasePagination):
     """
     The cursor pagination implementation is neccessarily complex.
     For an overview of the position/offset style we use, see this post:
     http://cramer.io/2011/03/08/building-cursors-for-the-disqus-api/
     """
     cursor_query_param = 'cursor'
-    page_size = api_settings.PAGE_SIZE
     invalid_cursor_message = _('Invalid cursor')
     ordering = '-created'
     template = 'rest_framework/pagination/previous_and_next.html'
 
     def paginate_queryset(self, queryset, request, view=None):
-        if self.page_size is None:
+        self.page_size = page_size = self.get_page_size(request)
+        if not page_size:
             return None
 
         self.base_url = request.build_absolute_uri()
@@ -540,8 +540,8 @@ class CursorPagination(BasePagination):
         # If we have an offset cursor then offset the entire page by that amount.
         # We also always fetch an extra item in order to determine if there is a
         # page following on from this one.
-        results = list(queryset[offset:offset + self.page_size + 1])
-        self.page = list(results[:self.page_size])
+        results = list(queryset[offset:offset + page_size + 1])
+        self.page = list(results[:page_size])
 
         # Determine the position of the final item following the page.
         if len(results) > len(self.page):
diff --git a/tests/test_pagination.py b/tests/test_pagination.py
index c67550c85..1c23c91bb 100644
--- a/tests/test_pagination.py
+++ b/tests/test_pagination.py
@@ -508,6 +508,8 @@ class TestCursorPagination:
 
         class ExamplePagination(pagination.CursorPagination):
             page_size = 5
+            page_size_query_param = 'page_size'
+            max_page_size = 20
             ordering = 'created'
 
         self.pagination = ExamplePagination()
@@ -643,6 +645,24 @@ class TestCursorPagination:
 
         assert isinstance(self.pagination.to_html(), type(''))
 
+    def test_page_size(self):
+        (previous, current, next, previous_url, next_url) = \
+            self.get_pages('/?page_size=10')
+
+        assert previous is None
+        assert current == [1, 1, 1, 1, 1, 1, 2, 3, 4, 4]
+        assert next == [4, 4, 5, 6, 7, 7, 7, 7, 7, 7]
+        assert 'page_size=10' in next_url
+
+        (previous, current, next, previous_url, next_url) = \
+            self.get_pages(next_url.replace('page_size=10', 'page_size=4'))
+
+        assert previous == [2, 3, 4, 4]
+        assert current == [4, 4, 5, 6]
+        assert next == [7, 7, 7, 7]
+        assert 'page_size=4' in previous_url
+        assert 'page_size=4' in next_url
+
 
 def test_get_displayed_page_numbers():
     """

From a6983565f87b6c40130ba4102e9f3cd89286712e Mon Sep 17 00:00:00 2001
From: homm <homm86@gmail.com>
Date: Fri, 12 Jun 2015 19:21:57 +0300
Subject: [PATCH 3/8] allow cursor format customization

---
 rest_framework/pagination.py | 28 +++++++++++++++++-----------
 1 file changed, 17 insertions(+), 11 deletions(-)

diff --git a/rest_framework/pagination.py b/rest_framework/pagination.py
index d5718dfc3..b5e890914 100644
--- a/rest_framework/pagination.py
+++ b/rest_framework/pagination.py
@@ -506,15 +506,10 @@ class CursorPagination(PageSizePaginationMixin, BasePagination):
         self.base_url = request.build_absolute_uri()
         self.ordering = self.get_ordering(request, queryset, view)
 
-        # Determine if we have a cursor, and if so then decode it.
-        encoded = request.query_params.get(self.cursor_query_param)
-        if encoded is None:
-            self.cursor = None
+        self.cursor = self.decode_cursor(request)
+        if self.cursor is None:
             (offset, reverse, current_position) = (0, False, None)
         else:
-            self.cursor = _decode_cursor(encoded)
-            if self.cursor is None:
-                raise NotFound(self.invalid_cursor_message)
             (offset, reverse, current_position) = self.cursor
 
         # Cursor pagination always enforces an ordering.
@@ -626,8 +621,7 @@ class CursorPagination(PageSizePaginationMixin, BasePagination):
                 position = self.previous_position
 
         cursor = Cursor(offset=offset, reverse=False, position=position)
-        encoded = _encode_cursor(cursor)
-        return replace_query_param(self.base_url, self.cursor_query_param, encoded)
+        return self.encode_cursor(cursor)
 
     def get_previous_link(self):
         if not self.has_previous:
@@ -675,8 +669,7 @@ class CursorPagination(PageSizePaginationMixin, BasePagination):
                 position = self.next_position
 
         cursor = Cursor(offset=offset, reverse=True, position=position)
-        encoded = _encode_cursor(cursor)
-        return replace_query_param(self.base_url, self.cursor_query_param, encoded)
+        return self.encode_cursor(cursor)
 
     def get_ordering(self, request, queryset, view):
         """
@@ -718,6 +711,19 @@ class CursorPagination(PageSizePaginationMixin, BasePagination):
             return (ordering,)
         return tuple(ordering)
 
+    def decode_cursor(self, request):
+        # Determine if we have a cursor, and if so then decode it.
+        encoded = request.query_params.get(self.cursor_query_param)
+        if encoded is not None:
+            cursor = _decode_cursor(encoded)
+            if cursor is None:
+                raise NotFound(self.invalid_cursor_message)
+            return cursor
+
+    def encode_cursor(self, cursor):
+        encoded = _encode_cursor(cursor)
+        return replace_query_param(self.base_url, self.cursor_query_param, encoded)
+
     def _get_position_from_instance(self, instance, ordering):
         attr = getattr(instance, ordering[0].lstrip('-'))
         return six.text_type(attr)

From 33e73632033be2abd1ddbb364d61a87b281cd726 Mon Sep 17 00:00:00 2001
From: homm <homm86@gmail.com>
Date: Sun, 14 Jun 2015 01:52:30 +0300
Subject: [PATCH 4/8] make MockObject, MockQuerySet and ExamplePagination
 visible outside of setup

---
 tests/test_pagination.py | 68 ++++++++++++++++++++--------------------
 1 file changed, 34 insertions(+), 34 deletions(-)

diff --git a/tests/test_pagination.py b/tests/test_pagination.py
index 1c23c91bb..63b909bea 100644
--- a/tests/test_pagination.py
+++ b/tests/test_pagination.py
@@ -186,6 +186,7 @@ class TestPageNumberPagination:
     def setup(self):
         class ExamplePagination(pagination.PageNumberPagination):
             page_size = 5
+
         self.pagination = ExamplePagination()
         self.queryset = range(1, 101)
 
@@ -475,54 +476,53 @@ class TestCursorPagination:
     """
     Unit tests for `pagination.CursorPagination`.
     """
+    class MockObject(object):
+        def __init__(self, idx):
+            self.created = idx
 
-    def setup(self):
-        class MockObject(object):
-            def __init__(self, idx):
-                self.created = idx
+    class MockQuerySet(object):
+        def __init__(self, items):
+            self.items = items
 
-        class MockQuerySet(object):
-            def __init__(self, items):
-                self.items = items
-
-            def filter(self, created__gt=None, created__lt=None):
-                if created__gt is not None:
-                    return MockQuerySet([
-                        item for item in self.items
-                        if item.created > int(created__gt)
-                    ])
-
-                assert created__lt is not None
-                return MockQuerySet([
+        def filter(self, created__gt=None, created__lt=None):
+            if created__gt is not None:
+                return type(self)([
                     item for item in self.items
-                    if item.created < int(created__lt)
+                    if item.created > int(created__gt)
                 ])
 
-            def order_by(self, *ordering):
-                if ordering[0].startswith('-'):
-                    return MockQuerySet(list(reversed(self.items)))
-                return self
+            assert created__lt is not None
+            return type(self)([
+                item for item in self.items
+                if item.created < int(created__lt)
+            ])
 
-            def __getitem__(self, sliced):
-                return self.items[sliced]
+        def order_by(self, *ordering):
+            if ordering[0].startswith('-'):
+                return type(self)(list(reversed(self.items)))
+            return self
 
-        class ExamplePagination(pagination.CursorPagination):
-            page_size = 5
-            page_size_query_param = 'page_size'
-            max_page_size = 20
-            ordering = 'created'
+        def __getitem__(self, sliced):
+            return self.items[sliced]
 
-        self.pagination = ExamplePagination()
-        self.queryset = MockQuerySet([
-            MockObject(idx) for idx in [
+    class ExamplePagination(pagination.CursorPagination):
+        page_size = 5
+        page_size_query_param = 'page_size'
+        max_page_size = 20
+        ordering = 'created'
+
+    def setup(self):
+        self.pagination = self.ExamplePagination()
+        self.queryset = self.MockQuerySet(
+            map(self.MockObject, [
                 1, 1, 1, 1, 1,
                 1, 2, 3, 4, 4,
                 4, 4, 5, 6, 7,
                 7, 7, 7, 7, 7,
                 7, 7, 7, 8, 9,
                 9, 9, 9, 9, 9
-            ]
-        ])
+            ])
+        )
 
     def get_pages(self, url):
         """

From 692893cda83afca8626e75473b8cdbc8c5497422 Mon Sep 17 00:00:00 2001
From: homm <homm86@gmail.com>
Date: Sun, 14 Jun 2015 01:53:11 +0300
Subject: [PATCH 5/8] test custom cursor format

---
 tests/test_pagination.py | 87 +++++++++++++++++++++++++++++++++++++++-
 1 file changed, 86 insertions(+), 1 deletion(-)

diff --git a/tests/test_pagination.py b/tests/test_pagination.py
index 63b909bea..402ee328c 100644
--- a/tests/test_pagination.py
+++ b/tests/test_pagination.py
@@ -2,8 +2,9 @@
 from __future__ import unicode_literals
 from rest_framework import exceptions, generics, pagination, serializers, status, filters
 from rest_framework.request import Request
-from rest_framework.pagination import PageLink, PAGE_BREAK
+from rest_framework.pagination import PageLink, PAGE_BREAK, Cursor
 from rest_framework.test import APIRequestFactory
+from rest_framework.utils.urls import replace_query_param, remove_query_param
 import pytest
 
 factory = APIRequestFactory()
@@ -511,6 +512,30 @@ class TestCursorPagination:
         max_page_size = 20
         ordering = 'created'
 
+    class CustomCursorPagination(ExamplePagination):
+        cursor_query_param = 'since'
+        reverse_query_param = 'before'
+
+        def decode_cursor(self, request):
+            rev = False
+            if self.reverse_query_param in request.query_params:
+                rev = True
+                query_param = self.reverse_query_param
+            elif self.cursor_query_param in request.query_params:
+                query_param = self.cursor_query_param
+            else:
+                return
+            return Cursor(0, rev, request.query_params[query_param])
+
+        def encode_cursor(self, cursor):
+            if cursor.reverse:
+                query_param = self.reverse_query_param
+                base_url = remove_query_param(self.base_url, self.cursor_query_param)
+            else:
+                query_param = self.cursor_query_param
+                base_url = remove_query_param(self.base_url, self.reverse_query_param)
+            return replace_query_param(base_url, query_param, cursor.position)
+
     def setup(self):
         self.pagination = self.ExamplePagination()
         self.queryset = self.MockQuerySet(
@@ -663,6 +688,66 @@ class TestCursorPagination:
         assert 'page_size=4' in previous_url
         assert 'page_size=4' in next_url
 
+    def test_custom_cursor_format(self):
+        # setup
+        self.pagination = self.CustomCursorPagination()
+        # The CustomCursorPagination expects unique keys
+        self.queryset = self.MockQuerySet(
+            map(self.MockObject, [
+                1, 2, 4, 8, 10,
+                11, 12, 13, 14, 15,
+                18, 33, 35, 36, 37,
+                38, 39, 40, 41,
+            ])
+        )
+
+        # actual test
+        (previous, current, next, previous_url, next_url) = self.get_pages('/')
+
+        assert previous is None
+        assert current == [1, 2, 4, 8, 10]
+        assert next == [11, 12, 13, 14, 15]
+        assert previous_url is None
+        assert 'since=10' in next_url
+
+        (previous, current, next, previous_url, next_url) = self.get_pages(next_url)
+
+        assert previous == [1, 2, 4, 8, 10]
+        assert current == [11, 12, 13, 14, 15]
+        assert next == [18, 33, 35, 36, 37]
+        assert 'before=11' in previous_url
+        assert 'since' not in previous_url
+        assert 'since=15' in next_url
+
+        (previous, current, next, previous_url, next_url) = self.get_pages(next_url)
+        (previous, current, next, previous_url, next_url) = self.get_pages(next_url)
+
+        assert previous == [18, 33, 35, 36, 37]
+        assert current == [38, 39, 40, 41]
+        assert next is None
+        assert 'before=38' in previous_url
+        assert 'since' not in previous_url
+        assert next_url is None
+
+        (previous, current, next, previous_url, next_url) = self.get_pages(previous_url)
+
+        assert previous == [11, 12, 13, 14, 15]
+        assert current == [18, 33, 35, 36, 37]
+        assert next == [38, 39, 40, 41]
+        assert 'before=18' in previous_url
+        assert 'since=37' in next_url
+        assert 'before' not in next_url
+
+        (previous, current, next, previous_url, next_url) = self.get_pages(previous_url)
+        (previous, current, next, previous_url, next_url) = self.get_pages(previous_url)
+
+        assert previous is None
+        assert current == [1, 2, 4, 8, 10]
+        assert next == [11, 12, 13, 14, 15]
+        assert previous_url is None
+        assert 'since=10' in next_url
+        assert 'before' not in next_url
+
 
 def test_get_displayed_page_numbers():
     """

From bacc29fb96d54359a60ac7b9e533b657691a9ce5 Mon Sep 17 00:00:00 2001
From: homm <homm86@gmail.com>
Date: Sun, 14 Jun 2015 14:35:39 +0300
Subject: [PATCH 6/8] fix tests on python3

---
 tests/test_pagination.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/test_pagination.py b/tests/test_pagination.py
index 402ee328c..18feb22f3 100644
--- a/tests/test_pagination.py
+++ b/tests/test_pagination.py
@@ -483,7 +483,7 @@ class TestCursorPagination:
 
     class MockQuerySet(object):
         def __init__(self, items):
-            self.items = items
+            self.items = list(items)
 
         def filter(self, created__gt=None, created__lt=None):
             if created__gt is not None:

From f899670afa38847c9449a8726ab77c806fc33745 Mon Sep 17 00:00:00 2001
From: homm <homm86@gmail.com>
Date: Tue, 23 Jun 2015 16:30:37 +0300
Subject: [PATCH 7/8] change classes hierarchy

---
 rest_framework/pagination.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/rest_framework/pagination.py b/rest_framework/pagination.py
index b5e890914..592786eea 100644
--- a/rest_framework/pagination.py
+++ b/rest_framework/pagination.py
@@ -201,7 +201,7 @@ class BasePagination(object):
         raise NotImplementedError('to_html() must be implemented to display page controls.')
 
 
-class PageSizePaginationMixin(object):
+class BasePageSizePagination(BasePagination):
     # The default page size.
     # Defaults to `None`, meaning pagination is disabled.
     page_size = api_settings.PAGE_SIZE
@@ -228,7 +228,7 @@ class PageSizePaginationMixin(object):
         return self.page_size
 
 
-class PageNumberPagination(PageSizePaginationMixin, BasePagination):
+class PageNumberPagination(BasePageSizePagination):
     """
     A simple page number based style that supports page numbers as
     query parameters. For example:
@@ -487,7 +487,7 @@ class LimitOffsetPagination(BasePagination):
         return template.render(context)
 
 
-class CursorPagination(PageSizePaginationMixin, BasePagination):
+class CursorPagination(BasePageSizePagination):
     """
     The cursor pagination implementation is neccessarily complex.
     For an overview of the position/offset style we use, see this post:

From d9ab8f5799196531542c2f96631a669b44643ced Mon Sep 17 00:00:00 2001
From: homm <homm86@gmail.com>
Date: Tue, 23 Jun 2015 16:32:06 +0300
Subject: [PATCH 8/8] do not use local page_size var

---
 rest_framework/pagination.py | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/rest_framework/pagination.py b/rest_framework/pagination.py
index 592786eea..586e7298d 100644
--- a/rest_framework/pagination.py
+++ b/rest_framework/pagination.py
@@ -499,8 +499,8 @@ class CursorPagination(BasePageSizePagination):
     template = 'rest_framework/pagination/previous_and_next.html'
 
     def paginate_queryset(self, queryset, request, view=None):
-        self.page_size = page_size = self.get_page_size(request)
-        if not page_size:
+        self.page_size = self.get_page_size(request)
+        if self.page_size is None:
             return None
 
         self.base_url = request.build_absolute_uri()
@@ -535,8 +535,8 @@ class CursorPagination(BasePageSizePagination):
         # If we have an offset cursor then offset the entire page by that amount.
         # We also always fetch an extra item in order to determine if there is a
         # page following on from this one.
-        results = list(queryset[offset:offset + page_size + 1])
-        self.page = list(results[:page_size])
+        results = list(queryset[offset:offset + self.page_size + 1])
+        self.page = list(results[:self.page_size])
 
         # Determine the position of the final item following the page.
         if len(results) > len(self.page):