"""
Ordering backend.
"""
from six import string_types
from rest_framework.filters import BaseFilterBackend
from rest_framework.settings import api_settings
__title__ = 'django_elasticsearch_dsl_drf.filter_backends.ordering.common'
__author__ = 'Artur Barseghyan <artur.barseghyan@gmail.com>'
__copyright__ = '2017-2018 Artur Barseghyan'
__license__ = 'GPL 2.0/LGPL 2.1'
__all__ = (
'DefaultOrderingFilterBackend',
'OrderingFilterBackend',
)
[docs]class OrderingFilterBackend(BaseFilterBackend):
"""Ordering filter backend for Elasticsearch.
Example:
>>> from django_elasticsearch_dsl_drf.filter_backends import (
>>> OrderingFilterBackend
>>> )
>>> from django_elasticsearch_dsl_drf.views import BaseDocumentViewSet
>>>
>>> # Local article document definition
>>> from .documents import ArticleDocument
>>>
>>> # Local article document serializer
>>> from .serializers import ArticleDocumentSerializer
>>>
>>> class ArticleDocumentView(BaseDocumentViewSet):
>>>
>>> document = ArticleDocument
>>> serializer_class = ArticleDocumentSerializer
>>> filter_backends = [OrderingFilterBackend,]
>>> ordering_fields = {
>>> 'id': 'id',
>>> 'title': 'title.raw',
>>> 'date_submitted': 'date_submitted',
>>> 'state': {
>>> 'field': 'state.raw',
>>> }
>>> }
>>> ordering = ('id', 'name',)
"""
ordering_param = api_settings.ORDERING_PARAM
# TODO: Either use or remove.
# @classmethod
# def prepare_ordering_fields(cls, view):
# """Prepare ordering fields.
#
# :param view: View.
# :type view: rest_framework.viewsets.ReadOnlyModelViewSet
# :return: Ordering options.
# :rtype: dict
# """
# ordering_fields = view.ordering_fields
# for field, options in ordering_fields.items():
# if options is None or isinstance(options, string_types):
# ordering_fields[field] = {
# 'field': options or field
# }
# elif 'field' not in ordering_fields[field]:
# ordering_fields[field]['field'] = field
# return ordering_fields
[docs] def get_ordering_query_params(self, request, view):
"""Get ordering query params.
:param request: Django REST framework request.
:param view: View.
:type request: rest_framework.request.Request
:type view: rest_framework.viewsets.ReadOnlyModelViewSet
:return: Ordering params to be used for ordering.
:rtype: list
"""
# TODO: Support `mode` argument.
query_params = request.query_params.copy()
ordering_query_params = query_params.getlist(self.ordering_param, [])
__ordering_params = []
# Remove invalid ordering query params
for query_param in ordering_query_params:
__key = query_param.lstrip('-')
__direction = '-' if query_param.startswith('-') else ''
if __key in view.ordering_fields:
__field_name = view.ordering_fields[__key] or __key
__ordering_params.append(
'{}{}'.format(__direction, __field_name)
)
# This is no longer needed. If you want to have a fallback, make use
# of ``DefaultOrderingFilterBackend``.
# # If no valid ordering params specified, fall back to `view.ordering`
# if not __ordering_params:
# return self.get_default_ordering_params(view)
return __ordering_params
# @classmethod
# def get_default_ordering_params(cls, view):
# """Get the default ordering params for the view.
#
# :param view: View.
# :type view: rest_framework.viewsets.ReadOnlyModelViewSet
# :return: Ordering params to be used for ordering.
# :rtype: list
# """
# ordering = getattr(view, 'ordering', None)
# if isinstance(ordering, string_types):
# return [ordering]
# return ordering
[docs] def filter_queryset(self, request, queryset, view):
"""Filter the queryset.
:param request: Django REST framework request.
:param queryset: Base queryset.
:param view: View.
:type request: rest_framework.request.Request
:type queryset: elasticsearch_dsl.search.Search
:type view: rest_framework.viewsets.ReadOnlyModelViewSet
:return: Updated queryset.
:rtype: elasticsearch_dsl.search.Search
"""
ordering_query_params = self.get_ordering_query_params(request, view)
if ordering_query_params:
return queryset.sort(*ordering_query_params)
return queryset
[docs]class DefaultOrderingFilterBackend(BaseFilterBackend):
"""Default ordering filter backend for Elasticsearch.
Make sure this is your last ordering backend.
Example:
>>> from django_elasticsearch_dsl_drf.filter_backends import (
>>> DefaultOrderingFilterBackend,
>>> OrderingFilterBackend
>>> )
>>> from django_elasticsearch_dsl_drf.views import BaseDocumentViewSet
>>>
>>> # Local article document definition
>>> from .documents import ArticleDocument
>>>
>>> # Local article document serializer
>>> from .serializers import ArticleDocumentSerializer
>>>
>>> class ArticleDocumentView(BaseDocumentViewSet):
>>>
>>> document = ArticleDocument
>>> serializer_class = ArticleDocumentSerializer
>>> filter_backends = [
>>> DefaultOrderingFilterBackend,
>>> OrderingFilterBackend,
>>> ]
>>> ordering_fields = {
>>> 'id': 'id',
>>> 'title': 'title.raw',
>>> 'date_submitted': 'date_submitted',
>>> 'state': {
>>> 'field': 'state.raw',
>>> }
>>> }
>>> ordering = 'name'
"""
ordering_param = api_settings.ORDERING_PARAM
[docs] def get_ordering_query_params(self, request, view):
"""Get ordering query params.
:param request: Django REST framework request.
:param view: View.
:type request: rest_framework.request.Request
:type view: rest_framework.viewsets.ReadOnlyModelViewSet
:return: Ordering params to be used for ordering.
:rtype: list
"""
query_params = request.query_params.copy()
ordering_query_params = query_params.getlist(self.ordering_param, [])
ordering_params_present = False
# Remove invalid ordering query params
for query_param in ordering_query_params:
__key = query_param.lstrip('-')
if __key in view.ordering_fields:
ordering_params_present = True
break
# If no valid ordering params specified, fall back to `view.ordering`
if not ordering_params_present:
return self.get_default_ordering_params(view)
return {}
[docs] @classmethod
def get_default_ordering_params(cls, view):
"""Get the default ordering params for the view.
:param view: View.
:type view: rest_framework.viewsets.ReadOnlyModelViewSet
:return: Ordering params to be used for ordering.
:rtype: list
"""
ordering = getattr(view, 'ordering', None)
if isinstance(ordering, string_types):
return [ordering]
return ordering
[docs] def filter_queryset(self, request, queryset, view):
"""Filter the queryset.
:param request: Django REST framework request.
:param queryset: Base queryset.
:param view: View.
:type request: rest_framework.request.Request
:type queryset: elasticsearch_dsl.search.Search
:type view: rest_framework.viewsets.ReadOnlyModelViewSet
:return: Updated queryset.
:rtype: elasticsearch_dsl.search.Search
"""
ordering_query_params = self.get_ordering_query_params(request, view)
if ordering_query_params:
return queryset.sort(*ordering_query_params)
return queryset