Question

我想将非平面结构序列化为一个扁平对象。这是我收到的API调用的一个例子（遗憾的是我无法控制它）：

{
"webhookEvent": "jira:issue_updated",
"user": {
        "id": 2434,
        "name": "Ben",
    },
"issue": {
      "id": "33062",
      "key": "jira-project-key-111",
      "fields": {
          "summary": "The week ahead",
      },
"changelog": {
    "id": "219580",
    "items": [{
         "field": "status",
         "fieldtype": "jira",
         "from": "10127",
         "fromString": "Submitted",
         "to": "10128",
         "toString": "Staged"
    }]
},
"timestamp": 1423234723378
}

我想把它序列化为这样的模型：

class Issue(models.Model):
    jira_id = models.IntegerField()
    jira_id = models.CharField()
    summary = models.CharField()

class Change(models.Model):
    issue = models.ForeignKey(Issue)
    timestamp = models.DataTimeField()

如您所见，模型Issue的字段summary与id和key位于同一对象上，与JSON数据不同。

My Serializer是下一个：

    class ChangeSerializer(serializers.ModelSerializer):
        """Receives complex data from jira and converts into objects."""

        issue = JiraIssueSerializer()
        timestamp = TimestampField(source='created_at')

        class Meta:
            model = Change
            fields = ('issue', 'timestamp')

        def create(self, validated_data):
            super(serializers.ModelSerializer, self).create(validated_data=validated_data)
            jira_issue = JiraIssueSerializer(data=validated_data)
            issue = Issue.objects.get(jira_issue)
            self.created_at = datetime.utcnow()
            change = Change(**validated_data)
            return change



    class JiraIssueSerializer(serializers.ModelSerializer):
        """Issue serializer."""
        id = serializers.IntegerField(source='jira_id')
        key = serializers.CharField(source='jira_key')
        summary = serializers.CharField()   ### I want field to work!
        # fields = serializers.DictField(child=serializers.CharField())

        class Meta:
            model = Issue
            fields = ('id', 'key',
               'summary',
            )

        def to_internal_value(self, data):
           # ret = super(serializers.ModelSerializer,   self).to_internal_value(data)
           ret = {}
           # ret = super().to_internal_value(data)
           ret['jira_id'] = data.get('id', None)
           ret['jira_key'] = data.get('key', None)
           jira_issue_fields_data = data.get('fields')
           if jira_issue_fields_data or 1:
               summary = jira_issue_fields_data.get('summary', None)
               ret.update(summary=summary)
            print('to_internal_value', ret)
            return ret

         def to_representation(self, instance):
            ret = {}
            ret = super().to_representation(instance)
            fields = {}
            fields['summary'] = instance.summary
            ret.update(fields=fields)
            print(ret)
            return ret

我适用于JSON中issue对象中的字段。但是，我如何向JiraIssueSerializer添加一些字段，如summary？它们不是issue对象的直接字段，而是位于子结构fields中。我看到了这些方式：

再制作一个模型Fields来保留它们，但这太荒谬了。我不需要它，我的API严格依赖于外来结构。
制作一些.to_internal_fields()转换器。但在这种情况下，我必须手动验证并准备我Issue中的所有字段并重复几次。此外，如果字段summary未在Serializer中登记，则后者无法使用它或验证失败。
将DictField添加到Serializer（在代码中注释）并从中获取数据。好吗？如何验证？同样，我有一个干净的代码结构。

接下来，我想解析并保存更改日志数据。

如何更好地处理此类结构？

谢谢！

Answer 1

最后，在django-rest-framework的测试中发现了解决方案 https://github.com/tomchristie/django-rest-framework/blob/master/tests/test_serializer.py#L149

您可以轻松定义嵌套序列化程序，它们将充当容器并将数据提取到普通对象。像这样：

    class NestedSerializer1(serializers.Serializer):
        a = serializers.IntegerField()
        b = serializers.IntegerField()

    class NestedSerializer2(serializers.Serializer):
        c = serializers.IntegerField()
        d = serializers.IntegerField()

    class TestSerializer(serializers.Serializer):
        nested1 = NestedSerializer1(source='*')
        nested2 = NestedSerializer2(source='*')

    data = {
        'nested1': {'a': 1, 'b': 2},
        'nested2': {'c': 3, 'd': 4}
     }

     serializer = TestSerializer(data=self.data)
     assert serializer.is_valid()

     assert serializer.validated_data == {
        'a': 1, 
        'b': 2,
        'c': 3, 
        'd': 4
    }

Answer 2

我建议你创建自己的自定义序列化程序来接收数据。你可以这样做：

from rest_framework import serializers

class MySerializer(serializers.Serializer):
    """
    Custom serializer
    """
    id = serializers.IntegerField(read_only=True)
    name = serializers.CharField()


    def create(self, validated_data):
        """Create a new object"""
        validated_data['custom_value'] = 0 # you can manipulate and restructure data here if you wish
        return MyModel.objects.create(**validated_data)

然后，您可以根据需要在create()功能中操作数据。您还可以创建嵌套的自定义序列化程序来解析此数据。

Answer 3

文档是处理nesting in serialisation的重要部分。

基本上，您要创建一个具有如下嵌套值的单独类：

class UserSerializer(serializers.Serializer):
    email = serializers.EmailField()
    username = serializers.CharField(max_length=100)

class CommentSerializer(serializers.Serializer):
    user = UserSerializer()
    content = serializers.CharField(max_length=200)
    created = serializers.DateTimeField()

Django Rest Framework：将数据从嵌套的json字段序列化为普通对象

3 个答案: