diff --git a/rest_framework/pagination.py b/rest_framework/pagination.py index bea10d036..081760e1c 100644 --- a/rest_framework/pagination.py +++ b/rest_framework/pagination.py @@ -449,13 +449,26 @@ class CursorPagination(BasePagination): http://cramer.io/2011/03/08/building-cursors-for-the-disqus-api/ """ cursor_query_param = 'cursor' + + # The default page size. + # Defaults to `None`, meaning pagination is disabled. page_size = api_settings.PAGE_SIZE + + # 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 + 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 = self.get_page_size(request) + if not self.page_size: return None self.base_url = request.build_absolute_uri() @@ -530,6 +543,19 @@ class CursorPagination(BasePagination): return self.page + 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.has_next: return None diff --git a/tests/test_pagination.py b/tests/test_pagination.py index 03c4fdf47..0ab149d07 100644 --- a/tests/test_pagination.py +++ b/tests/test_pagination.py @@ -513,6 +513,8 @@ class TestCursorPagination: class ExamplePagination(pagination.CursorPagination): page_size = 5 + page_size_query_param = 'page_size' + max_page_size = 20 ordering = 'created' self.pagination = ExamplePagination() @@ -648,6 +650,24 @@ 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(): """