Django REST Framework：ModelSerializer 是否可以选择通过 GET 或 (POST, PUT, DELETE) 动态更改字段？

Question

ModelSerializer 是否可以选择通过 GET 或（POST、PUT、DELETE）动态更改字段？

虽然 GET 需要复杂的字段，例如嵌套序列化程序，但 (POST、PUT、DELETE) 不需要这些。

我认为解决方案是为 GET 和（POST、PUT、DELETE）使用单独的序列化程序。但在那种情况下，我将不得不创建很多无用的序列化程序。有什么好的解决办法吗？

class PlaylistSerializer(serializers.ModelSerializer):
    user = UserDetailSerializer(read_only=True)
    tracks = serializers.SerializerMethodField()
    is_owner = serializers.SerializerMethodField()
    is_added = serializers.SerializerMethodField()
    is_favorited = serializers.BooleanField()

    class Meta:
        model = Playlist
        fields = (
            "pk",
            "user",
            "title",
            "views",
            "is_public",
            "is_wl",
            "created_at",
            "updated_at",
            "tracks",
            "is_owner",
            "is_added",
            "is_favorited",
        )

    def get_is_owner(self, obj):
        return obj.user == self.context["request"].user

    def get_tracks(self, obj):
        queryset = obj.track_set
        if queryset.exists():
            tracks = TrackSerializer(queryset, context=self.context, many=True).data
            return tracks
        else:
            return []

    def get_is_added(self, obj):
        try:
            return obj.is_added
        except AttributeError:
            return False


class PlaylistUpdateSerializer(serializers.ModelSerializer):
    class Meta:
        model = Playlist
        fields = ("title", "is_public")

Answer 1

首先您需要创建一个 class 并从此 class 继承您的序列化程序，如下所示：

from rest_framework import serializers


class DynamicFieldsModelSerializer(serializers.ModelSerializer):
    """To be used alongside DRF's serializers.ModelSerializer"""
    @classmethod
    def default_fieldset(cls):
       return cls.Meta.fields

    def __init__(self, *args, **kwargs):
        self.requested_fields = self._extract_fieldset(**kwargs)
        # Fields should be popped otherwise next line complains about 
unexpected kwarg
        kwargs.pop('fields', None)
        super().__init__(*args, **kwargs)
        self._limit_fields(self.requested_fields)

    def _extract_fieldset(self, **kwargs):
        requested_fields = kwargs.pop('fields', None)
        if requested_fields is not None:
            return requested_fields

        context = kwargs.pop('context', None)
        if context is None:
            return None

        return context.get('fields')

    def _limit_fields(self, allowed_fields=None):
        if allowed_fields is None:
            to_exclude = set(self.fields.keys()) - set(self.default_fieldset())
        else:
            to_exclude = set(self.fields.keys()) - set(allowed_fields)
        for field_name in to_exclude or []:
            self.fields.pop(field_name)

    @classmethod
    def all_fields_minus(cls, *removed_fields):
        return set(cls.Meta.fields) - set(removed_fields)

那么你的序列化程序将是这样的：

class PlaylistSerializer(DynamicFieldsModelSerializer):
    class Meta:
        model = Playlist
        fields = ("pk", "user", "title", "views", "is_public",
        "is_wl", "created_at", "updated_at", "tracks", "is_owner",
        "is_added", "is_favorited",)

    @classmethod
    def update_serializer(cls):
        return ("title", "is_public")
    
    @classmethod
    def view_serializer(cls):
        return ("title", "is_public", "is_owner", "is_added")

然后你将调用你的序列化程序如下：

PlaylistSerializer(instance, fields=PlaylistSerializer.update_serializer()).data

Django REST Framework：ModelSerializer 是否可以选择通过 GET 或 (POST, PUT, DELETE) 动态更改字段？

Django REST Framework: Does ModelSerializer have an option to change the fields dynamically by GET or (POST, PUT, DELETE)?

django

django-rest-framework