DRF - 整数数组

Question

我需要将整数数组发送到 DRF 序列化器。

序列化器是：

class ItemSerializer(serializers.Serializer):
    id = serializers.IntegerField(required = False)
    selected_items = serializers.ListField(child = serializers.IntegerField())

在 FE 中，我只需通过打字稿发布一个数组：

createItem () {
    let tmp: any = {};
    const itemData = new FormData();
    itemData.append('id',1);
    itemData.append('selected_items', this.current.selected_items.map( e => e.id))

    return this.itemService.createItem( itemData )
        .subscribe( data => this.goBack( data ),
            err => {
                console.log( err );
                this.toastr.error( 'Item not saved', 'Error' )
            } );
}

itemService.createItem只做一个http.post

当 FE 发送数据到 BE 时，selected_items 字段被编码为selected_items=1,2（通过wireshark验证）。当从 DRF 解析数据时，该字段被编码为selected_items=['1,2']. 因此该字段未经过验证，因为 1,2 不是有效整数。

Answer 1

如果您在请求中获取逗号分隔值，那么您可能需要在进行验证之前将其转换为实际列表。

只需重写to_internal_value()序列化器中的方法即可转换值。

class ItemSerializer(serializers.Serializer):
    id = serializers.IntegerField(required = False)
    selected_items = serializers.ListField(child = serializers.IntegerField())

    def to_internal_value(self, data):
        """
        method is called to restore a primitive datatype into its internal python representation. This method should raise a serializers.ValidationError if the data is invalid. 
        reference: https://www.django-rest-framework.org/api-guide/fields/#custom-fields
        """
        # Convert comma separated digits to list of integers
        data['selected_items'] = data['selected_items'].split(',') if data['selected_items'] else []
        return data

否则，您可以编写自定义字段级验证：

class ItemSerializer(serializers.Serializer):
    id = serializers.IntegerField(required = False)
    selected_items = serializers.ListField(child = serializers.IntegerField())

    def validate_selected_items(self, value):
        """
        You can specify custom field-level validation by adding .validate_<field_name> methods to your Serializer subclass.
        reference: https://www.django-rest-framework.org/api-guide/serializers/#field-level-validation
        """
        # Convert comma separated digits to list of integers
        return value.split(',') if value else []