django-rest-framework/rest_framework/utils/serializer_helpers.py
2015-06-25 16:10:17 -04:00

123 lines
3.7 KiB
Python

from __future__ import unicode_literals
import collections
from rest_framework.compat import OrderedDict, unicode_to_repr
class ReturnDict(OrderedDict):
"""
Return object from `serialier.data` for the `Serializer` class.
Includes a backlink to the serializer instance for renderers
to use if they need richer field information.
"""
def __init__(self, *args, **kwargs):
self.serializer = kwargs.pop('serializer')
super(ReturnDict, self).__init__(*args, **kwargs)
def copy(self):
return ReturnDict(self, serializer=self.serializer)
def __repr__(self):
return dict.__repr__(self)
def __reduce__(self):
# Pickling these objects will drop the .serializer backlink,
# but preserve the raw data.
return (dict, (dict(self),))
class ReturnList(list):
"""
Return object from `serialier.data` for the `SerializerList` class.
Includes a backlink to the serializer instance for renderers
to use if they need richer field information.
"""
def __init__(self, *args, **kwargs):
self.serializer = kwargs.pop('serializer')
super(ReturnList, self).__init__(*args, **kwargs)
def __repr__(self):
return list.__repr__(self)
def __reduce__(self):
# Pickling these objects will drop the .serializer backlink,
# but preserve the raw data.
return (list, (list(self),))
class BoundField(object):
"""
A field object that also includes `.value` and `.error` properties.
Returned when iterating over a serializer instance,
providing an API similar to Django forms and form fields.
"""
def __init__(self, field, value, errors, prefix=''):
self._field = field
self.value = value
self.errors = errors
self.name = prefix + self.field_name
def __getattr__(self, attr_name):
return getattr(self._field, attr_name)
@property
def _proxy_class(self):
return self._field.__class__
def __repr__(self):
return unicode_to_repr('<%s value=%s errors=%s>' % (
self.__class__.__name__, self.value, self.errors
))
class NestedBoundField(BoundField):
"""
This `BoundField` additionally implements __iter__ and __getitem__
in order to support nested bound fields. This class is the type of
`BoundField` that is used for serializer fields.
"""
def __iter__(self):
for field in self.fields.values():
yield self[field.field_name]
def __getitem__(self, key):
field = self.fields[key]
value = self.value.get(key) if self.value else None
error = self.errors.get(key) if self.errors else None
if hasattr(field, 'fields'):
return NestedBoundField(field, value, error, prefix=self.name + '.')
return BoundField(field, value, error, prefix=self.name + '.')
class BindingDict(collections.MutableMapping):
"""
This dict-like object is used to store fields on a serializer.
This ensures that whenever fields are added to the serializer we call
`field.bind()` so that the `field_name` and `parent` attributes
can be set correctly.
"""
def __init__(self, serializer):
self.serializer = serializer
self.fields = OrderedDict()
def __setitem__(self, key, field):
self.fields[key] = field
field.bind(field_name=key, parent=self.serializer)
def __getitem__(self, key):
return self.fields[key]
def __delitem__(self, key):
del self.fields[key]
def __iter__(self):
return iter(self.fields)
def __len__(self):
return len(self.fields)
def __repr__(self):
return dict.__repr__(self.fields)