详解从Django Rest Framework响应中删除空字段
我使用django-rest-framework开发了一个API.
我正在使用ModelSerializer返回模型的数据.
models.py
class MetaTags(models.Model):
title = models.CharField(_('Title'), max_length=255, blank=True, null=True)
name = models.CharField(_('Name'), max_length=255, blank=True, null=True)
serializer.py
class MetaTagsSerializer(serializers.ModelSerializer): class Meta: model = MetaTags
响应
{
"meta": {
"title": null,
"name": "XYZ"
}
}
理想情况下,在API响应中,不应在响应中发送任何不存在的值.
当标题为null时,我希望响应为：
{
"meta": {
"name": "XYZ"
}
}
您可以尝试覆盖to_native函数：
class MetaTagsSerializer(serializers.ModelSerializer):
class Meta:
model = MetaTags
def to_native(self, obj):
"""
Serialize objects -> primitives.
"""
ret = self._dict_class()
ret.fields = self._dict_class()
for field_name, field in self.fields.items():
if field.read_only and obj is None:
continue
field.initialize(parent=self, field_name=field_name)
key = self.get_field_key(field_name)
value = field.field_to_native(obj, field_name)
# Continue if value is None so that it does not get serialized.
if value is None:
continue
method = getattr(self, 'transform_%s' % field_name, None)
if callable(method):
value = method(obj, value)
if not getattr(field, 'write_only', False):
ret[key] = value
ret.fields[key] = self.augment_field(field, field_name, key, value)
return ret
我基本上从serializers.BaseSerializer复制了基本的to_native函数,并添加了一个值的检查.
更新：
至于DRF 3.0,to_native()被重命名为to_representation(),其实现稍有改变.这是DRF 3.0的代码,它忽略空值和空字符串值：
def to_representation(self, instance): """ Object instance -> Dict of primitive datatypes. """ ret = OrderedDict() fields = self._readable_fields for field in fields: try: attribute = field.get_attribute(instance) except SkipField: continue # KEY IS HERE: if attribute in [None, '']: continue # We skip `to_representation` for `None` values so that fields do # not have to explicitly deal with that case. # # For related fields with `use_pk_only_optimization` we need to # resolve the pk value. check_for_none = attribute.pk if isinstance(attribute, PKOnlyObject) else attribute if check_for_none is None: ret[field.field_name] = None else: ret[field.field_name] = field.to_representation(attribute) return ret
翻译自：https://stackoverflow.com/questions/27015931/remove-null-fields-from-django-rest-framework-response
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