Django REST Framework基础：序列化

一、表结构：

class Article(models.Model):
    id = models.AutoField(primary_key=True)
    title = models.CharField(max_length=64)
    create_time = models.DateField(auto_now=True)
    type = models.SmallIntegerField(
        choices=((1, '原创'), (2, '转载')),
        default=1
    )
    source = models.ForeignKey(to='Source', on_delete=models.CASCADE)
    tag = models.ManyToManyField(to='Tag')

class Source(models.Model):
    id = models.AutoField(primary_key=True)
    name = models.CharField(max_length=32, unique=True, error_messages={"unique": '校区名称不能重复'})

class Tag(models.Model):
    id = models.AutoField(primary_key=True)
    name = models.CharField(max_length=32)

class Comment(models.Model):
    content = models.CharField(max_length=255)
    article = models.ForeignKey(to='Article', on_delete=models.CASCADE)

二、单表的GET和POST:

1、路由：

url(r'source/', views.SourceView.as_view()),

2、序列化类：

class SourceSerializer(serializers.ModelSerializer):

    def validate_name(self, value):
        if '草' in value:
            raise ValidationError('不符合社会主义核心价值观')
        return value

    class Meta:
        model = models.Source
        fields = "__all__"

3、视图：

class SourceView(APIView):

    def get(self, request, *args, **kwargs):
        res = {"code": 0}
        all_source = models.Source.objects.all()
        ser_obj = SourceSerializer(all_source, many=True)
        res["data"] = ser_obj.data
        return Response(res)

    def post(self, request, *args, **kwargs):
        res = {"code": 0}
        ser_obj = SourceSerializer(data=request.data)
        if ser_obj.is_valid():
            # 数据没问题
            ser_obj.save()
            return Response(res)
        else:
            res["code"] = 1
            res["error"] = ser_obj.errors
            return Response(res)

三、外键的GET和POST:

1、路由：

url(r'comment/', views.Comment.as_view()),

2、序列化：

class CommentSerializer(serializers.ModelSerializer):
    class Meta:
        model = models.Comment
        fields = "__all__"
        extra_kwargs = {
            "content": {"error_messages": {"required": "评论内容不能为空"}},
            "article": {"error_messages": {"required": "文章不能为空"}}
        }

3、视图：

class Comment(APIView):
    def get(self, request, *args, **kwargs):
        res = {"code": 0}
        all_data = models.Comment.objects.all()
        ser_obj = CommentSerializer(all_data, many=True)
        res["data"] = ser_obj.data
        return Response(res)

    def post(self, request, *args, **kwargs):
        res = {"code": 0}
        ser_obj = CommentSerializer(data=request.data)
        if ser_obj.is_valid():
            ser_obj.save()
        else:
            res["code"] = 1
            res["error"] = ser_obj.errors
        return Response(res)

四、多对多的GET和POST:

1、路由：

url(r'article/', views.ArticleList.as_view()),

2、序列化：

class TagSerializer(serializers.ModelSerializer):

    class Meta:
        model = models.Tag
        fields = "__all__"

class ArticleSerializer(serializers.ModelSerializer):
    type = serializers.CharField(source="get_type_display")
    tag = TagSerializer(many=True)

    class Meta:
        model = models.Article
        fields = ["id", "title", "type", "source", "tag"]

class ArticleWriteSerializer(serializers.ModelSerializer):

    class Meta:
        model = models.Article
        fields = "__all__"
        extra_kwargs = {
            "tag": {
                "error_messages": {
                    "does_not_exist": '"{pk_value}"对应的tag对象不存在。'
                }
            }
        }

3、视图：

class ArticleList(APIView):
    def get(self, request, *args, **kwargs):
        res = {"code": 0}
        article_list = models.Article.objects.all()
        ser_obj = ArticleSerializer(article_list, many=True)
        res["data"] = ser_obj.data
        return Response(res)

    def post(self, request, *args, **kwargs):
        res = {"code": 0}
        ser_obj = ArticleWriteSerializer(data=request.data)
        if ser_obj.is_valid():
            ser_obj.save()
        else:
            res["code"] = 1
            res["error"] = ser_obj.errors
        return Response(res)

五、超链接的序列化：

1、路由：

urlpatterns = [
    url(r'articlelinked/', views.ArticleLinked.as_view()),,
    url(r'source/(?P<pk>\d+)', views.SourceDetailView.as_view(), name='source-detail'),
]

2、序列化：

class ArticleHyperlinkedSerializer(serializers.HyperlinkedModelSerializer):
    source = serializers.HyperlinkedIdentityField(view_name='source-detail', lookup_field='source_id', lookup_url_kwarg='pk')

    class Meta:
        model = models.Article
        fields = ["id", "type", "title", "source"]
        depth = 1

3、视图：

class ArticleLinked(APIView):
    def get(self, request, *args, **kwargs):
        res = {"code": 0}
        article_list = models.Article.objects.all()
        ser_obj = ArticleHyperlinkedSerializer(article_list, many=True, context={'request': request})
        res["data"] = ser_obj.data
        return Response(res)