67 lines
2.6 KiB
Python
67 lines
2.6 KiB
Python
from rest_framework import pagination, serializers
|
|
|
|
|
|
class PaginationSerializer(pagination.PaginationSerializer):
|
|
"""
|
|
Custom PaginationSerializer for openedx.
|
|
|
|
Adds the following fields:
|
|
- num_pages: total number of pages
|
|
- current_page: the current page being returned
|
|
- start: the index of the first page item within the overall collection
|
|
"""
|
|
start_page = 1 # django Paginator.page objects have 1-based indexes
|
|
num_pages = serializers.Field(source='paginator.num_pages')
|
|
current_page = serializers.SerializerMethodField('get_current_page')
|
|
start = serializers.SerializerMethodField('get_start')
|
|
sort_order = serializers.SerializerMethodField('get_sort_order')
|
|
|
|
def get_current_page(self, page):
|
|
"""Get the current page"""
|
|
return page.number
|
|
|
|
def get_start(self, page):
|
|
"""Get the index of the first page item within the overall collection"""
|
|
return (self.get_current_page(page) - self.start_page) * page.paginator.per_page
|
|
|
|
def get_sort_order(self, page): # pylint: disable=unused-argument
|
|
"""Get the order by which this collection was sorted"""
|
|
return self.context.get('sort_order')
|
|
|
|
|
|
class CollapsedReferenceSerializer(serializers.HyperlinkedModelSerializer):
|
|
"""Serializes arbitrary models in a collapsed format, with just an id and url."""
|
|
id = serializers.CharField(read_only=True) # pylint: disable=invalid-name
|
|
url = serializers.HyperlinkedIdentityField(view_name='')
|
|
|
|
def __init__(self, model_class, view_name, id_source='id', lookup_field=None, *args, **kwargs):
|
|
"""Configures the serializer.
|
|
|
|
Args:
|
|
model_class (class): Model class to serialize.
|
|
view_name (string): Name of the Django view used to lookup the
|
|
model.
|
|
id_source (string): Optional name of the id field on the model.
|
|
Defaults to 'id'.
|
|
lookup_field (string): Optional name of the model field used to
|
|
lookup the model in the view. Defaults to the value of
|
|
id_source.
|
|
"""
|
|
if not lookup_field:
|
|
lookup_field = id_source
|
|
|
|
self.Meta.model = model_class
|
|
|
|
super(CollapsedReferenceSerializer, self).__init__(*args, **kwargs)
|
|
|
|
self.fields['id'].source = id_source
|
|
self.fields['url'].view_name = view_name
|
|
self.fields['url'].lookup_field = lookup_field
|
|
|
|
class Meta(object):
|
|
"""Defines meta information for the ModelSerializer.
|
|
|
|
model is set dynamically in __init__.
|
|
"""
|
|
fields = ("id", "url")
|