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Diffstat (limited to 'rest_framework/pagination.py')
| -rw-r--r-- | rest_framework/pagination.py | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/rest_framework/pagination.py b/rest_framework/pagination.py new file mode 100644 index 00000000..131718fd --- /dev/null +++ b/rest_framework/pagination.py @@ -0,0 +1,80 @@ +from rest_framework import serializers + +# TODO: Support URLconf kwarg-style paging + + +class NextPageField(serializers.Field): + """ + Field that returns a link to the next page in paginated results. + """ + def to_native(self, value): + if not value.has_next(): + return None + page = value.next_page_number() + request = self.context.get('request') + relative_url = '?page=%d' % page + if request: + return request.build_absolute_uri(relative_url) + return relative_url + + +class PreviousPageField(serializers.Field): + """ + Field that returns a link to the previous page in paginated results. + """ + def to_native(self, value): + if not value.has_previous(): + return None + page = value.previous_page_number() + request = self.context.get('request') + relative_url = '?page=%d' % page + if request: + return request.build_absolute_uri('?page=%d' % page) + return relative_url + + +class PaginationSerializerOptions(serializers.SerializerOptions): + """ + An object that stores the options that may be provided to a + pagination serializer by using the inner `Meta` class. + + Accessible on the instance as `serializer.opts`. + """ + def __init__(self, meta): + super(PaginationSerializerOptions, self).__init__(meta) + self.object_serializer_class = getattr(meta, 'object_serializer_class', + serializers.Field) + + +class BasePaginationSerializer(serializers.Serializer): + """ + A base class for pagination serializers to inherit from, + to make implementing custom serializers more easy. + """ + _options_class = PaginationSerializerOptions + 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 + object_serializer = self.opts.object_serializer_class + self.fields[results_field] = object_serializer(source='object_list') + + def to_native(self, obj): + """ + Prevent default behaviour of iterating over elements, and serializing + each in turn. + """ + return self.convert_object(obj) + + +class PaginationSerializer(BasePaginationSerializer): + """ + A default implementation of a pagination serializer. + """ + count = serializers.Field(source='paginator.count') + next = NextPageField(source='*') + previous = PreviousPageField(source='*') |
