Python rest_framework.serializers 模块，PrimaryKeyRelatedField() 实例源码

def serializer_factory(endpoint=None, fields=None, base_class=None, model=None):

    if model is not None:
        assert endpoint is None, "You cannot specify both a model and an endpoint"
        from .endpoints import Endpoint
        endpoint = Endpoint(model=model)
    else:
        assert endpoint is not None, "You have to specify either a model or an endpoint"

    if base_class is None:
        base_class = endpoint.base_serializer

    meta_attrs = {
        'model': endpoint.model,
        'fields': fields if fields is not None else endpoint.get_fields_for_serializer()
    }
    meta_parents = (object, )
    if hasattr(base_class, 'Meta'):
        meta_parents = (base_class.Meta, ) + meta_parents

    Meta = type('Meta', meta_parents, meta_attrs)

    cls_name = '{}Serializer'.format(endpoint.model.__name__)
    cls_attrs = {
        'Meta': Meta,
    }

    for meta_field in meta_attrs['fields']:
        if meta_field not in base_class._declared_fields:
            try:
                model_field = endpoint.model._meta.get_field(meta_field)
                if isinstance(model_field, OneToOneRel):
                    cls_attrs[meta_field] = serializers.PrimaryKeyRelatedField(read_only=True)
                elif isinstance(model_field, ManyToOneRel):
                    cls_attrs[meta_field] = serializers.PrimaryKeyRelatedField(many=True, read_only=True)
            except FieldDoesNotExist:
                cls_attrs[meta_field] = serializers.ReadOnlyField()

    return type(cls_name, (NullToDefaultMixin, base_class, ), cls_attrs)

def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)

        for i in range(1, settings.STECHEC_NPLAYERS + 1):
            f = serializers.PrimaryKeyRelatedField(queryset=models.Champion.objects.all(), write_only=True)
            self.fields['champion_%d' % i] = f

        if settings.STECHEC_USE_MAPS:
            self.fields['map'] = serializers.PrimaryKeyRelatedField(queryset=models.Map.objects.all(), write_only=True)

def _extract_field_info(self, model, field_name, field, fields, relationships, adapter, target_app, allow_recursion=False):
        if field_name == 'id':
            return None
        field_item = {
            'name': field_name,
            'type': adapter.field_type_mapping[field.__class__.__name__]
        }
        if isinstance(field, PrimaryKeyRelatedField) or isinstance(field, ManyRelatedField) \
                or isinstance(field, ModelSerializer):
            if model is None:
                field_item['related_model'] = field.queryset.model._meta.model_name.lower()
                field_item['app'] = target_app if target_app is not None else \
                    field.queryset.model._meta.app_label.lower()
                relationships.append(field_item)
            else:
                model_field = model._meta.get_field(field_name)
                field_item['related_model'] = model_field.related_model._meta.model_name.lower()
                field_item['app'] = target_app if target_app is not None else \
                    model_field.related_model._meta.app_label.lower()
                relationships.append(field_item)
                if hasattr(model_field, 'field'):
                    field_item['inverse'] = model_field.field.name
                elif hasattr(model_field, 'remote_field') and \
                        getattr(model_field.remote_field, 'related_name', None) is not None:
                    field_item['inverse'] = model_field.remote_field.related_name
                if field_item.get('inverse', '-')[-1] == '+':
                    field_item.pop('inverse')
            if isinstance(field, ModelSerializer):
                if hasattr(field, 'many') and field.many:
                    field_item['type'] = adapter.field_type_mapping['ManyRelatedField']
                else:
                    field_item['type'] = adapter.field_type_mapping['PrimaryKeyRelatedField']
        elif isinstance(field, ModelSerializer):
            field_item['related_model'] = field.queryset.model._meta.model_name.lower()
            field_item['app'] = target_app if target_app is not None else \
                field.queryset.model._meta.app_label.lower()
            relationships.append(field_item)
            if field.many:
                field_item['type'] = adapter.field_type_mapping['ManyRelatedField']
            else:
                field_item['type'] = adapter.field_type_mapping['PrimaryKeyRelatedField']
        elif isinstance(field, ListSerializer):
            child_rels = []
            child_fields = []
            self._extract_field_info(model, field_name, field.child, child_fields, child_rels, adapter, target_app)
            if len(child_rels) > 0:
                for item in child_rels:
                    item['type'] = adapter.field_type_mapping['ManyRelatedField']
                    item.pop('inverse', None)
                    relationships.append(item)
            else:
                field_item['type'] = adapter.field_type_mapping('ListField')
                fields.append(field_item)

        else:
            fields.append(field_item)

        return field_item