DRF 序列化器的 BooleanField returns null for empty ForeignKey field

Question

我想将布尔字段 has_video 和 has_gallery 添加到我的序列化程序。

如果 MyModel（视频、画廊）的 ForeignKey 字段有值，则它们的值应为 true，否则这些值应设置为 false。

models.py

class MyModel(models.Model):
    video = models.ForeignKey(
        to='videos.Video',
        null=True,
        blank=True,
        on_delete=models.SET_NULL,
    )
    gallery = models.ForeignKey(
        to='galleries.Gallery',
        null=True,
        blank=True,
        on_delete=models.SET_NULL,
    )

serializers.py

class MyModelSerializer(serializers.ModelSerializer):
    has_video = serializers.BooleanField(source='video', default=False)
    has_gallery = serializers.BooleanField(source='gallery', default=False)

当 MyModel 对象的视频或画廊值为 null 时出现问题。我希望 returned 值是假的，但它是空的。

        "has_video": null,
        "has_gallery": null,

我尝试将 allow_null 参数设置为 false 但结果是一样的（值仍然是 null）。

has_video = serializers.BooleanField(source='video', default=False, allow_null=False)
has_gallery = serializers.BooleanField(source='gallery', default=False, allow_null=False)

当视频或图库不为 null 时，序列化程序的字段 return 如我所料为真。问题只是关于 null/false 个值。

Answer 1

这是我在我的一个项目中采用的方法。

class MyModelSerializer(serializers.ModelSerializer):
    has_video = serializers.SerializerMethodField('get_has_video', read_only=True)
    has_gallery = serializers.SerializerMethodField(source='get_has_gallery', read_only=True)
    # ... Your other fields 
    class Meta:
        model = "Your model name"
        fields = ("your model fields",
                  ,"has_video", "has_gallery") # include the above two fields
        
    def get_has_video(self, obj):
        # now your object should be having videos then you want True so do this like this
        return True if obj.video else False
    
    def get_has_gallery(self, obj):
        # now your object should be having galleries then you want True so do this like this
        return True if obj.gallery else False

DRF 序列化器的 BooleanField returns null for empty ForeignKey field

DRF serializer's BooleanField returns null for empty ForeignKey field

python

django

django-models

django-rest-framework

foreign-keys