02_Tutorial 2: Requests and Responses 请求和响应

# ## Tutorial 2: Requests and Responses

from rest_framework import status               # status模块中的每个状态代码
from rest_framework.decorators import api_view
from rest_framework.response import Response
from snippets.models import Snippet
from snippets.serializers import SnippetSerializer


@api_view([‘GET‘, ‘POST‘])      # 基于函数视图, 编写API视图的包装器  等价于  基于类视图的APIView类
def snippet_list(request, format=None):     # 可选的格式后缀
    """
    列出所有的snippets，或者创建一个新的snippet。
    """
    if request.method == ‘GET‘:
        snippets = Snippet.objects.all()
        serializer = SnippetSerializer(snippets, many=True)
        return Response(serializer.data)                    # return Response(data) 渲染成客户端请求的内容类型。

    elif request.method == ‘POST‘:
        serializer = SnippetSerializer(data=request.data)   # request.data  # 处理任意数据  适用于‘POST‘，‘PUT‘和‘PATCH‘方法
        if serializer.is_valid():
            serializer.save()
            return Response(serializer.data, status=status.HTTP_201_CREATED)    # status模块中的每个状态代码

        return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)


@api_view([‘GET‘, ‘PUT‘, ‘DELETE‘])
def snippet_detail(request, pk, format=None):       # 可选的格式后缀
    """
    获取，更新或删除一个snippet实例。
    """
    try:
        snippet = Snippet.objects.get(pk=pk)
    except Snippet.DoesNotExist:
        return Response(status=status.HTTP_404_NOT_FOUND)

    if request.method == ‘GET‘:
        serializer = SnippetSerializer(snippet)
        return Response(serializer.data, status=status.HTTP_200_OK)

    elif request.method == ‘POST‘:
        serializer = SnippetSerializer(snippet, data=request.data)   # request.data可以处理传入的json请求，但它也可以处理其他格式。
        if serializer.is_valid():
            serializer.save()
            return Response(serializer.data, status=status.HTTP_200_OK)
        return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)

    elif request.method == ‘DELETE‘:
        snippet.delete()
        return Response(status=status.HTTP_204_NO_CONTENT)