序列化的另一个思路


# 混入类，提供Model实例to_dict方法
class ModelMixin(object):
    __slots__ = ()

    def to_dict(self, excludes: tuple = None, selects: tuple = None) -> dict:
        if not hasattr(self, '_meta'):
            raise TypeError(
                '<%r> does not a django.db.models.Model object.' % self)
        elif selects:
            return {f: getattr(self, f) for f in selects}
        elif excludes:
            return {f.attname: getattr(self, f.attname) for f in self._meta.fields if f.attname not in excludes}
        else:
            return {f.attname: getattr(self, f.attname) for f in self._meta.fields}

    def update_by_dict(self, data):
        for key, value in data.items():
            setattr(self, key, value)
        self.save()


class App(models.Model, ModelMixin):
    name = models.CharField(max_length=50)
    key = models.CharField(max_length=50, unique=True)
    desc = models.CharField(max_length=255, null=True)
    rel_apps = models.TextField(null=True)
    rel_services = models.TextField(null=True)
    sort_id = models.IntegerField(default=0, db_index=True)
    created_at = models.CharField(max_length=20, default=human_datetime)
    created_by = models.ForeignKey(User, on_delete=models.PROTECT)

    def to_dict(self, *args, **kwargs):
        tmp = super().to_dict(*args, **kwargs)
        tmp['rel_apps'] = json.loads(self.rel_apps) if self.rel_apps else []
        tmp['rel_services'] = json.loads(
            self.rel_services) if self.rel_services else []
        return tmp

    def __repr__(self):
        return f'<App {self.name!r}>'

    class Meta:
        db_table = 'apps'
        ordering = ('-sort_id',)