Python rest_framework.settings.api_settings.PAGE_SIZE Examples

def get_previous_link(request):
    """ Generate URL of previous page in pagination. """
    limit = int(request.query_params.get('limit', api_settings.PAGE_SIZE))
    offset = int(request.query_params.get('offset', 0))

    if offset <= 0:
        return None

    url = request.build_absolute_uri()
    url = replace_query_param(url, 'limit', limit)

    if offset - limit <= 0:
        return remove_query_param(url, 'offset')

    offset = offset - limit
    return replace_query_param(url, 'offset', offset) 

def pagination_system_check(app_configs, **kwargs):
    errors = []
    # Use of default page size setting requires a default Paginator class
    from rest_framework.settings import api_settings
    if api_settings.PAGE_SIZE and not api_settings.DEFAULT_PAGINATION_CLASS:
        errors.append(
            Warning(
                "You have specified a default PAGE_SIZE pagination rest_framework setting,"
                "without specifying also a DEFAULT_PAGINATION_CLASS.",
                hint="The default for DEFAULT_PAGINATION_CLASS is None. "
                     "In previous versions this was PageNumberPagination. "
                     "If you wish to define PAGE_SIZE globally whilst defining "
                     "pagination_class on a per-view basis you may silence this check.",
                id="rest_framework.W001"
            )
        )
    return errors 

def paginate_results(request, *qs_serializers):
    """
    Custom pagination to handle multiple querysets and renderers.
    Supports serializing 1 to many different querysets. Based of DRF's
    LimitOffsetPagination. Useful when adding pagination to a regular
    APIView.

    qs_serializers - tuple of a queryset/array and respective serializer
    """
    limit = int(request.query_params.get('limit', api_settings.PAGE_SIZE))
    offset = int(request.query_params.get('offset', 0))

    count = 0
    cur_offset = offset
    out = []
    for qs, serializer in qs_serializers:
        len_func = ('__len__' if isinstance(qs, list) else 'count')
        qs_len = getattr(qs, len_func)()
        count += qs_len
        if (len(out) < limit):
            end_index = min([limit - len(out) + cur_offset, qs_len])
            qs = qs[cur_offset:end_index]
            if qs:
                out += serializer(qs, many=True).data
            cur_offset = max([cur_offset - end_index, 0])

    return OrderedDict([
        ('count', count),
        ('next', get_next_link(request, count)),
        ('previous', get_previous_link(request)),
        ('results', out),
    ]) 

def get_next_link(request, count):
    """ Generate URL of next page in pagination. """
    limit = int(request.query_params.get('limit', api_settings.PAGE_SIZE))
    offset = int(request.query_params.get('offset', 0))

    if offset + limit >= count:
        return None

    url = request.build_absolute_uri()
    url = replace_query_param(url, 'limit', limit)

    offset = offset + limit
    return replace_query_param(url, 'offset', offset) 

def test_next_link(self):
        req = self._get_request('/foo')
        assert (
            get_next_link(req, 200) ==
            'http://testserver/foo?limit={}&offset=100'.format(
                api_settings.PAGE_SIZE)) 

def test_previous_link(self):
        req = self._get_request('/foo', {'offset': 200})
        resp = get_previous_link(req)
        assert (
            resp == 'http://testserver/foo?limit={}&offset=100'.format(
                api_settings.PAGE_SIZE))

        req = self._get_request('/foo', {'offset': api_settings.PAGE_SIZE})
        resp = get_previous_link(req)
        assert (
            resp == 'http://testserver/foo?limit={}'.format(
                api_settings.PAGE_SIZE)) 

def __init__(
            self,
            results=None,
            count=None,
            current_page=None,
            page_size=api_settings.PAGE_SIZE,
    ):
        self.results = results
        self.count = count
        self.current_page = current_page
        self.page_size = page_size 

def test_response_count_matches_results(self):
        """
        Tests to ensure that the value in the count field matches the number of results returned in
        the response.
        :return: None
        """
        response = self.send(user=self.auth_user)
        content = response.json()
        if content["count"] <= api_settings.PAGE_SIZE:
            self.assertEqual(content["count"], len(content["results"]))