枚举Django Rest Framework序列化程序中的模型选择

时间:2015-03-25 02:43:19

标签: django angularjs rest django-rest-framework

我有一个使用Django选择字段的模型,如下所示:

class Question(models.Model):
QUESTION_TYPES = (
    (10,'Blurb'),
    (20,'Group Header'),
    (21,'Group Footer'),
    (30,'Sub-Group Header'),
    (31,'Sub-Group Footer'),
    (50,'Save Button'),
    (100,'Standard Question'),
    (105,'Text-Area Question'),
    (110,'Multiple-Choice Question'),
    (120,'Standard Sub-Question'),
    (130,'Multiple-Choice Sub-Question')
)
type = models.IntegerField(default=100,choices=QUESTION_TYPES)

我使用Django Rest Framework将此模型作为API呈现给Angular Web应用程序。在我的Angular Web应用程序中,我想要一个组合框小部件,随着所有这些选择而下降。不是整数,而是文本选择,例如" blurb","标准问题"等等。

现在,我可以将组合框手动编写到Angular应用程序中,但是根据DRY的精神,是否可以编写只返回这些选择的DRF序列化程序(即QUESTION_TYPES对象),这样我就可以填充组合带有ReST查询的框?

通过"可能",我想我的意思是"简单而优雅"。也许我的意思是" ReSTful"。 (以这种方式这样做是否很重要?)

只是想知道。 。

由于

约翰

3 个答案:

答案 0 :(得分:4)

我可能会尝试以下内容:

# models.py
class Question(models.Model):
    QUESTION_NAMES = (
        'Blurb',
        'Group Header',
        'Group Footer',
        'Sub-Group Header',
        'Sub-Group Footer',
        'Save Button',
        'Standard Question',
        'Text-Area Question',
        'Multiple-Choice Question',
        'Standard Sub-Question',
        'Multiple-Choice Sub-Question')
    QUESTION_VALS = (10, 20, 21, 30,
                     31, 50, 100, 105, 110,
                     120, 130)
    QUESTION_TYPES = tuple(zip(QUESTION_VALS, QUESTION_NAMES))
    # Personal choice here: I never name attribs after Python built-ins:
    qtype = models.IntegerField(default=100,choices=QUESTION_TYPES)

以下内容无法正常工作

(以下是我对序列化对象列表的原始直觉,但它不起作用。无论如何我都把它留在这里,因为它似乎应该有效。)

好的,我们有办法自己访问字符串,现在我们只需要序列化它们,为此,我可能会尝试使用ListField in DRF3,应该支持source kwarg,我想?

# serializers.py
from .models import Question
class YourSerializer(ModelSerializer):
    names = serializers.ListField(
       child=serializers.CharField(max_length=40),
       source=Question.QUESTION_NAMES
    )
    class Meta:
        model = Question
        fields = ('names', etc.)

以下内容会返回结果列表

后备:使用SerializerMethodField

from .models import Question

class YourSerializer(serializers.ModelSerializer):
    ...
    names = serializers.SerializerMethodField()

    def get_names(self, obj):
        return Question.QUESTION_NAMES

    class Meta:
        model = Question

<强>演示:

In [1]: q = Question.objects.create()
Out[1]: <Question: Question object>  

In [2]: ser = YourSerializer(q)

In [3]: ser.data
Out[3]: {'id': 1, 'names': ['Blurb', 'Group Header', 'Group Footer', 'Sub-Group Header', 'Sub-Group Footer', 'Save Button', 'Standard Question', 'Text-Area Question', 'Multiple-Choice Question', 'Standard Sub-Question', 'Multiple-Choice Sub-Question'], 'qtype': 100}

答案 1 :(得分:2)

如果您将ModelViewSetModelSerializer结合使用,OPTIONS请求将返回可用于获取选项的元数据。

from models import Question
from rest_framework import serializers

class QuestionSerializer(serializers.ModelSerializer):
    class Meta:
        model = Question


from rest_framework.viewsets import ModelViewSet
class QuestionChoicesViewSet(ModelViewSet):
    queryset = Question.objects.all()
    serializer_class = QuestionSerializer

这将为您提供包含actions属性的响应,该属性可能如下所示:

"actions": {
    "POST": {
        "id": {
            "type": "integer",
            "required": false,
            "read_only": true,
            "label": "ID"
        },
        "qtype": {
            "type": "choice",
            "required": false,
            "read_only": false,
            "label": "Qtype",
            "choices": [
                {
                    "display_name": "Blurb",
                    "value": 10
                },
                {
                    "display_name": "Group Header",
                    "value": 20
                },
                {
                    "display_name": "Group Footer",
                    "value": 21
                },
                {
                    "display_name": "Sub-Group Header",
                    "value": 30
                },
                //...
        }
    }
}

您可以对choices上的qtype属性进行迭代,以获取所有可用选项。

要更熟悉此主题,您可以阅读:Metadata

答案 2 :(得分:0)

我通过为仅使用GET动词的选项创建API端点来实现此目的。

models.py

QUESTION_TYPES = (
    (10,'Blurb'),
    (20,'Group Header'),
    (21,'Group Footer'),
    (30,'Sub-Group Header'),
    (31,'Sub-Group Footer'),
    (50,'Save Button'),
    (100,'Standard Question'),
    (105,'Text-Area Question'),
    (110,'Multiple-Choice Question'),
    (120,'Standard Sub-Question'),
    (130,'Multiple-Choice Sub-Question')
)

class Question(models.Model):
    type = models.IntegerField(default=100,choices=QUESTION_TYPES)

viewsets.py

from models import QUESTION_NAMES, Question
from rest_framework import serializers
class QuestionSerializer(serializers.ModelSerializer):
    type = serializers.ChoiceField(choices=QUESTION_NAMES, default=100)
    class Meta:
        model = Question

from rest_framework.response import Response
from rest_framework.views import APIView
class QuestionChoicesViewSet(APIView):
    def get(self, request):
        return Response(QUESTION_NAMES)

from rest_framework import viewsets
class QuestionViewSet(viewsets.ModelViewSet):
    queryset = Question.objects.all()
    serializer_class = QuestionSerializer