mirror of
https://github.com/encode/django-rest-framework.git
synced 2024-11-23 01:57:00 +03:00
90 lines
2.9 KiB
Python
90 lines
2.9 KiB
Python
"""
|
|
Pagination serializers determine the structure of the output that should
|
|
be used for paginated responses.
|
|
"""
|
|
from __future__ import unicode_literals
|
|
from rest_framework import serializers
|
|
from rest_framework.templatetags.rest_framework import replace_query_param
|
|
|
|
|
|
class NextPageField(serializers.Field):
|
|
"""
|
|
Field that returns a link to the next page in paginated results.
|
|
"""
|
|
page_field = 'page'
|
|
|
|
def to_representation(self, value):
|
|
if not value.has_next():
|
|
return None
|
|
page = value.next_page_number()
|
|
request = self.context.get('request')
|
|
url = request and request.build_absolute_uri() or ''
|
|
return replace_query_param(url, self.page_field, page)
|
|
|
|
|
|
class PreviousPageField(serializers.Field):
|
|
"""
|
|
Field that returns a link to the previous page in paginated results.
|
|
"""
|
|
page_field = 'page'
|
|
|
|
def to_representation(self, value):
|
|
if not value.has_previous():
|
|
return None
|
|
page = value.previous_page_number()
|
|
request = self.context.get('request')
|
|
url = request and request.build_absolute_uri() or ''
|
|
return replace_query_param(url, self.page_field, page)
|
|
|
|
|
|
class DefaultObjectSerializer(serializers.ReadOnlyField):
|
|
"""
|
|
If no object serializer is specified, then this serializer will be applied
|
|
as the default.
|
|
"""
|
|
|
|
def __init__(self, source=None, many=None, context=None):
|
|
# Note: Swallow context and many kwargs - only required for
|
|
# eg. ModelSerializer.
|
|
super(DefaultObjectSerializer, self).__init__(source=source)
|
|
|
|
|
|
class BasePaginationSerializer(serializers.Serializer):
|
|
"""
|
|
A base class for pagination serializers to inherit from,
|
|
to make implementing custom serializers more easy.
|
|
"""
|
|
results_field = 'results'
|
|
|
|
def __init__(self, *args, **kwargs):
|
|
"""
|
|
Override init to add in the object serializer field on-the-fly.
|
|
"""
|
|
super(BasePaginationSerializer, self).__init__(*args, **kwargs)
|
|
results_field = self.results_field
|
|
|
|
try:
|
|
object_serializer = self.Meta.object_serializer_class
|
|
except AttributeError:
|
|
object_serializer = DefaultObjectSerializer
|
|
|
|
try:
|
|
list_serializer_class = object_serializer.Meta.list_serializer_class
|
|
except AttributeError:
|
|
list_serializer_class = serializers.ListSerializer
|
|
|
|
self.fields[results_field] = list_serializer_class(
|
|
child=object_serializer(),
|
|
source='object_list'
|
|
)
|
|
self.fields[results_field].bind(field_name=results_field, parent=self)
|
|
|
|
|
|
class PaginationSerializer(BasePaginationSerializer):
|
|
"""
|
|
A default implementation of a pagination serializer.
|
|
"""
|
|
count = serializers.ReadOnlyField(source='paginator.count')
|
|
next = NextPageField(source='*')
|
|
previous = PreviousPageField(source='*')
|