serializerMixin

mixin.py

class SerializerMixin(object):
    """
    Mixin class for models.
    Model define::
        class User(SerializerMixin):
            id = None
            name = None
            fields = ('id', 'name')
            def __init__(self, _id, name):
                self.id = _id
                self.name = name
    Model serialize::
        u = User(1, 'Loup')
        u.serialize()
    """

    def serialize(self, fields=[], origin_class=None):
        result = dict()
        exclude_fields = []
        if hasattr(self, 'exclude_fields'):
            exclude_fields = getattr(self, 'exclude_fields')
        if not fields:
            if hasattr(self, '_sa_class_manager'):
                fields = getattr(self, '_sa_class_manager').keys()
            elif hasattr(self, 'fields'):
                fields = getattr(self, 'fields')
            else:
                return result
        for field in fields:
            if field in exclude_fields:
                continue
            if hasattr(self, field):
                value = getattr(self, field)
            else:
                continue
            value = self._get_cleaned_value(value, origin_class)
            if value is not None:
                result[field] = value

        if hasattr(self, 'get_external_data'):
            f = getattr(self, 'get_external_data')
            result.update(f())
        return result

    def _get_cleaned_value(self, value, origin_class=None):
        if origin_class is not None and isinstance(value, origin_class):
            return None
        if isinstance(value, self.__class__):
            if hasattr(self, 'self_fields'):
                fields = getattr(self, 'self_fields')
                return value.serialize(fields)
            else:
                return value.serialize()
        elif isinstance(value, list):
            return [v.serialize(origin_class=self.__class__) for v in value]
        elif isinstance(value, datetime.date):
            return value.strftime('%Y-%m-%d %H:%M:%S')
        elif SerializerMixin in value.__class__.__bases__:
            return value.serialize()
        else:
            return value