drf Response浅析
响应
Rsponse
当一个请求完成后，我们一般都会返回drf中的Rsponse对象，那么该对象其中最重要的作用就是序列化。
将需要返回给页面的数据进行JSON处理，除此之外还会对返回的页面等进行包装，它的内部其实也挺有趣儿的。
下面是Rsponse的签名：
def __init__(self, data=None, status=None,
template_name=None, headers=None,
exception=False, content_type=None):
参数详解：
| 参数 | 描述 |
|---|---|
| data | 返回的数据，内部会进行序列化，需传入一个字典 |
| status | 返回的状态码，默认是200 |
| template_name | 渲染并返回的模板 |
| headers | 返回的响应头，可以组织一个字典往响应头中放入token信息等 |
| content_type | 响应的编码格式，入application/json以及text/html等 |
有了这些参数，我们可以这样做：
from rest_framework.response import Response
from rest_framework.views import APIView
class Test(APIView):
def get(self,request):
ret_Msg = {"status":"100","message":""} # 返回的信息
return Response(
data=ret_Msg,
status=200, # 代表成功
headers={"token":"xxxx"},
)
这样的话在postman中就能拿到返回的token：
返回状态码
drf中内置了很多状态码的常量，我们在返回状态码时可以使用它们。
# from rest_framework import status
HTTP_100_CONTINUE = 100
HTTP_101_SWITCHING_PROTOCOLS = 101
HTTP_200_OK = 200
HTTP_201_CREATED = 201
HTTP_202_ACCEPTED = 202
HTTP_203_NON_AUTHORITATIVE_INFORMATION = 203
HTTP_204_NO_CONTENT = 204
HTTP_205_RESET_CONTENT = 205
HTTP_206_PARTIAL_CONTENT = 206
HTTP_207_MULTI_STATUS = 207
HTTP_208_ALREADY_REPORTED = 208
HTTP_226_IM_USED = 226
HTTP_300_MULTIPLE_CHOICES = 300
HTTP_301_MOVED_PERMANENTLY = 301
HTTP_302_FOUND = 302
HTTP_303_SEE_OTHER = 303
HTTP_304_NOT_MODIFIED = 304
HTTP_305_USE_PROXY = 305
HTTP_306_RESERVED = 306
HTTP_307_TEMPORARY_REDIRECT = 307
HTTP_308_PERMANENT_REDIRECT = 308
HTTP_400_BAD_REQUEST = 400
HTTP_401_UNAUTHORIZED = 401
HTTP_402_PAYMENT_REQUIRED = 402
HTTP_403_FORBIDDEN = 403
HTTP_404_NOT_FOUND = 404
HTTP_405_METHOD_NOT_ALLOWED = 405
HTTP_406_NOT_ACCEPTABLE = 406
HTTP_407_PROXY_AUTHENTICATION_REQUIRED = 407
HTTP_408_REQUEST_TIMEOUT = 408
HTTP_409_CONFLICT = 409
HTTP_410_GONE = 410
HTTP_411_LENGTH_REQUIRED = 411
HTTP_412_PRECONDITION_FAILED = 412
HTTP_413_REQUEST_ENTITY_TOO_LARGE = 413
HTTP_414_REQUEST_URI_TOO_LONG = 414
HTTP_415_UNSUPPORTED_MEDIA_TYPE = 415
HTTP_416_REQUESTED_RANGE_NOT_SATISFIABLE = 416
HTTP_417_EXPECTATION_FAILED = 417
HTTP_418_IM_A_TEAPOT = 418
HTTP_422_UNPROCESSABLE_ENTITY = 422
HTTP_423_LOCKED = 423
HTTP_424_FAILED_DEPENDENCY = 424
HTTP_426_UPGRADE_REQUIRED = 426
HTTP_428_PRECONDITION_REQUIRED = 428
HTTP_429_TOO_MANY_REQUESTS = 429
HTTP_431_REQUEST_HEADER_FIELDS_TOO_LARGE = 431
HTTP_451_UNAVAILABLE_FOR_LEGAL_REASONS = 451
HTTP_500_INTERNAL_SERVER_ERROR = 500
HTTP_501_NOT_IMPLEMENTED = 501
HTTP_502_BAD_GATEWAY = 502
HTTP_503_SERVICE_UNAVAILABLE = 503
HTTP_504_GATEWAY_TIMEOUT = 504
HTTP_505_HTTP_VERSION_NOT_SUPPORTED = 505
HTTP_506_VARIANT_ALSO_NEGOTIATES = 506
HTTP_507_INSUFFICIENT_STORAGE = 507
HTTP_508_LOOP_DETECTED = 508
HTTP_509_BANDWIDTH_LIMIT_EXCEEDED = 509
HTTP_510_NOT_EXTENDED = 510
HTTP_511_NETWORK_AUTHENTICATION_REQUIRED = 511
配置Rsponse
如果你在浏览器中访问该页面，可以发现它返回的其实是一个页面：
但是在postman中，返回的则是json格式的字符串。
{
"status": "100",
"message": ""
}
原因是因为它会根据request对象中的请求头accept来自动转换对应的数据格式，如果前端请求中未进行Accept声明，则会采用默认方式处理响应数据，我们可以通过配置来修改默认响应格式。
可以在rest_framework.settings查找所有的drf默认配置项
DEFAULTS = {
'DEFAULT_RENDERER_CLASSES': [
'rest_framework.renderers.JSONRenderer', # 返回json
'rest_framework.renderers.BrowsableAPIRenderer', # 返回页面
],
}
如果我们想让浏览器访问页面时也返回JSON格式，则可以进行下面两种配置方法。
局部配置
只指定某一个视图返回规定的数据格式：
from rest_framework.response import Response
from rest_framework.views import APIView
from rest_framework import settings
from rest_framework.renderers import JSONRenderer
class Test(APIView):
renderer_classes=[JSONRenderer,] # 该视图只返回JSON数据
def get(self,request):
ret_Msg = {"status":"100","message":""} # 返回的信息
return Response(
data=ret_Msg,
status=200, # 代表成功
headers={"token":"xxxx"},
)
全局配置
由于它返回时查找顺序是先找局部，再找Django.settings.py，最后再找rest_framework.settings.py，所以我们可以再Django.settings.py下进行覆写：
REST_FRAMEWORK = {
'DEFAULT_RENDERER_CLASSES': [
'rest_framework.renderers.JSONRenderer', # 所有视图均返回JSON格式数据
],
}
