Source code for marshmallow_mongoengine.schema

# -*- coding: utf-8 -*-
import copy

from mongoengine.base import BaseDocument
import marshmallow as ma
from marshmallow.compat import with_metaclass
from marshmallow_mongoengine.convert import ModelConverter


DEFAULT_SKIP_VALUES = (None, [], {})


[docs]class SchemaOpts(ma.SchemaOpts): """Options class for `ModelSchema`. Adds the following options: - ``model``: The Mongoengine Document model to generate the `Schema` from (required). - ``model_fields_kwargs``: Dict of {field: kwargs} to provide as additionals argument during fields creation. - ``model_build_obj``: If true, :Schema load: returns a :model: objects instead of a dict (default: True). - ``model_converter``: `ModelConverter` class to use for converting the Mongoengine Document model to marshmallow fields. - ``model_dump_only_pk``: If the document autogenerate it primary_key (default behaviour in Mongoengine), ignore it from the incomming data (default: False) - ``model_skip_values``: Skip the field if it contains one of the given values (default: None, [] and {}) """ def __init__(self, meta): super(SchemaOpts, self).__init__(meta) self.model = getattr(meta, 'model', None) if self.model and not issubclass(self.model, BaseDocument): raise ValueError("`model` must be a subclass of mongoengine.base.BaseDocument") self.model_fields_kwargs = getattr(meta, 'model_fields_kwargs', {}) self.model_dump_only_pk = getattr(meta, 'model_dump_only_pk', False) self.model_converter = getattr(meta, 'model_converter', ModelConverter) self.model_build_obj = getattr(meta, 'model_build_obj', True) self.model_skip_values = getattr(meta, 'model_skip_values', DEFAULT_SKIP_VALUES)
class SchemaMeta(ma.schema.SchemaMeta): """Metaclass for `ModelSchema`.""" # override SchemaMeta @classmethod def get_declared_fields(mcs, klass, *args, **kwargs): """Updates declared fields with fields converted from the Mongoengine model passed as the `model` class Meta option. """ declared_fields = kwargs.get('dict_class', dict)() # Generate the fields provided through inheritance opts = klass.opts model = getattr(opts, 'model', None) if model: converter = opts.model_converter() declared_fields.update(converter.fields_for_model( model, fields=opts.fields )) # Generate the fields provided in the current class base_fields = super(SchemaMeta, mcs).get_declared_fields( klass, *args, **kwargs ) declared_fields.update(base_fields) # Customize fields with provided kwargs for field_name, field_kwargs in klass.opts.model_fields_kwargs.items(): field = declared_fields.get(field_name, None) if field: # Copy to prevent alteration of a possible parent class's field field = copy.copy(field) for key, value in field_kwargs.items(): setattr(field, key, value) declared_fields[field_name] = field if opts.model_dump_only_pk and opts.model: # If primary key is automatically generated (nominal case), we # must make sure this field is read-only if opts.model._auto_id_field is True: field_name = opts.model._meta['id_field'] id_field = declared_fields.get(field_name) if id_field: # Copy to prevent alteration of a possible parent class's field id_field = copy.copy(id_field) id_field.dump_only = True declared_fields[field_name] = id_field return declared_fields
[docs]class ModelSchema(with_metaclass(SchemaMeta, ma.Schema)): """Base class for Mongoengine model-based Schemas. Example: :: from marshmallow_mongoengine import ModelSchema from mymodels import User class UserSchema(ModelSchema): class Meta: model = User """ OPTIONS_CLASS = SchemaOpts @ma.post_dump def _remove_skip_values(self, data): to_skip = self.opts.model_skip_values return { key: value for key, value in data.items() if value not in to_skip } @ma.post_load def _make_object(self, data): if self.opts.model_build_obj and self.opts.model: return self.opts.model(**data) else: return data
[docs] def update(self, obj, data): """Helper function to update an already existing document instead of creating a new one. :param obj: Mongoengine Document to update :param data: incomming payload to deserialize :return: an :class UnmarshallResult: Example: :: from marshmallow_mongoengine import ModelSchema from mymodels import User class UserSchema(ModelSchema): class Meta: model = User def update_obj(id, payload): user = User.objects(id=id).first() result = UserSchema().update(user, payload) result.data is user # True Note: Given the update is done on a existing object, the required param on the fields is ignored """ # TODO: find a cleaner way to skip required validation on update required_fields = [k for k, f in self.fields.items() if f.required] for field in required_fields: self.fields[field].required = False loaded_data, errors = self._do_load(data, postprocess=False) for field in required_fields: self.fields[field].required = True if not errors: # Update the given obj fields for k, v in loaded_data.items(): # Skip default values that have been automatically # added during unserialization if k in data: setattr(obj, k, v) return ma.UnmarshalResult(data=obj, errors=errors)