from collections import OrderedDict
from django.shortcuts import get_object_or_404
from rest_framework import serializers
import graphene
from graphene.relay.mutation import ClientIDMutation
from graphene.types import Field, InputField
from graphene.types.mutation import MutationOptions
from graphene.types.objecttype import yank_fields_from_attrs
from ..types import ErrorType
from .serializer_converter import convert_serializer_field
class SerializerMutationOptions(MutationOptions):
lookup_field = None
model_class = None
model_operations = ["create", "update"]
serializer_class = None
def fields_for_serializer(
serializer,
only_fields,
exclude_fields,
is_input=False,
convert_choices_to_enum=True,
):
fields = OrderedDict()
for name, field in serializer.fields.items():
is_not_in_only = only_fields and name not in only_fields
is_excluded = any(
[
name in exclude_fields,
field.write_only
and not is_input, # don't show write_only fields in Query
field.read_only and is_input, # don't show read_only fields in Input
]
)
if is_not_in_only or is_excluded:
continue
fields[name] = convert_serializer_field(
field, is_input=is_input, convert_choices_to_enum=convert_choices_to_enum
)
return fields
class SerializerMutation(ClientIDMutation):
class Meta:
abstract = True
errors = graphene.List(
ErrorType, description="May contain more than one error for same field."
)
@classmethod
def __init_subclass_with_meta__(
cls,
lookup_field=None,
serializer_class=None,
model_class=None,
model_operations=("create", "update"),
only_fields=(),
exclude_fields=(),
convert_choices_to_enum=True,
**options
):
if not serializer_class:
raise Exception("serializer_class is required for the SerializerMutation")
if "update" not in model_operations and "create" not in model_operations:
raise Exception('model_operations must contain "create" and/or "update"')
serializer = serializer_class()
if model_class is None:
serializer_meta = getattr(serializer_class, "Meta", None)
if serializer_meta:
model_class = getattr(serializer_meta, "model", None)
if lookup_field is None and model_class:
lookup_field = model_class._meta.pk.name
input_fields = fields_for_serializer(
serializer,
only_fields,
exclude_fields,
is_input=True,
convert_choices_to_enum=convert_choices_to_enum,
)
output_fields = fields_for_serializer(
serializer,
only_fields,
exclude_fields,
is_input=False,
convert_choices_to_enum=convert_choices_to_enum,
)
_meta = SerializerMutationOptions(cls)
_meta.lookup_field = lookup_field
_meta.model_operations = model_operations
_meta.serializer_class = serializer_class
_meta.model_class = model_class
_meta.fields = yank_fields_from_attrs(output_fields, _as=Field)
input_fields = yank_fields_from_attrs(input_fields, _as=InputField)
super(SerializerMutation, cls).__init_subclass_with_meta__(
_meta=_meta, input_fields=input_fields, **options
)
@classmethod
def get_serializer_kwargs(cls, root, info, **input):
lookup_field = cls._meta.lookup_field
model_class = cls._meta.model_class
if model_class:
if "update" in cls._meta.model_operations and lookup_field in input:
instance = get_object_or_404(
model_class, **{lookup_field: input[lookup_field]}
)
partial = True
elif "create" in cls._meta.model_operations:
instance = None
partial = False
else:
raise Exception(
'Invalid update operation. Input parameter "{}" required.'.format(
lookup_field
)
)
return {
"instance": instance,
"data": input,
"context": {"request": info.context},
"partial": partial,
}
return {"data": input, "context": {"request": info.context}}
@classmethod
def mutate_and_get_payload(cls, root, info, **input):
kwargs = cls.get_serializer_kwargs(root, info, **input)
serializer = cls._meta.serializer_class(**kwargs)
if serializer.is_valid():
return cls.perform_mutate(serializer, info)
else:
errors = ErrorType.from_errors(serializer.errors)
return cls(errors=errors)
@classmethod
def perform_mutate(cls, serializer, info):
obj = serializer.save()
kwargs = {}
for f, field in serializer.fields.items():
if not field.write_only:
if isinstance(field, serializers.SerializerMethodField):
kwargs[f] = field.to_representation(obj)
else:
kwargs[f] = field.get_attribute(obj)
return cls(errors=None, **kwargs)
