document.py 文件源码

def from_json(cls, json_str, created=False, *args, **kwargs):
        """
        Decode from human-readable json.

        Parameters:
            json_str: JSON string that should be passed to the serialized
            created: a parameter that is passed to cls._from_son.
            *args, **kwargs: Any additional arguments that is passed to
                json.loads.
        """
        from .fields import FollowReferenceField
        hook = generate_object_hook(cls)
        if "object_hook" not in kwargs:
            kwargs["object_hook"] = hook
        dct = json.loads(json_str, *args, **kwargs)
        for name, fld in cls._fields.items():
            if any([
                getattr(fld, "exclude_from_json", None),
                getattr(fld, "exclude_json", None)
            ]):
                dct.pop(name, None)
        from_son_result = cls._from_son(SON(dct), created=created)

        @singledispatch
        def normalize_reference(ref_id, fld):
            """Normalize Reference."""
            return ref_id and fld.to_python(ref_id) or None

        @normalize_reference.register(dict)
        def normalize_reference_dict(ref_id, fld):
            """Normalize Reference for dict."""
            return fld.to_python(ref_id["id"])

        @normalize_reference.register(list)
        def normalize_reference_list(ref_id, fld):
            """Normalize Reference for list."""
            return [
                normalize_reference(ref.id, fld) for ref in ref_id
            ]

        for fldname, fld in cls._fields.items():
            target = fld.field if isinstance(fld, db.ListField) else fld

            if not isinstance(target, db.ReferenceField) or \
                    isinstance(target, FollowReferenceField):
                continue

            value = dct.get(fldname)
            setattr(
                from_son_result, fldname,
                normalize_reference(getattr(value, "id", value), target)
            )
        return from_son_result