rest-framework分页器,相应器,解析器,url控制器,版本控制
一、分页器
1、简单分页(查看第n页,每页显示n条)
from rest_framework.pagination import PageNumberPagination
# 一 基本使用:url=url=http://127.0.0.1:8000/pager/?page=2&size=3,size无效
class Pager(APIView):
def get(self,request,*args,**kwargs):
# 获取所有数据
ret=models.Book.objects.all()
# 创建分页对象
page=PageNumberPagination()
# 在数据库中获取分页的数据
page_list=page.paginate_queryset(ret,request,view=self)
# 对分页进行序列化
ser=BookSerializer1(instance=page_list,many=True)
return Response(ser.data)
# 二 自定制 url=http://127.0.0.1:8000/pager/?page=2&size=3
# size=30,无效,最多5条
class Mypage(PageNumberPagination):
page_size = 2
page_query_param = 'page'
# 定制传参
page_size_query_param = 'size'
# 最大一页的数据
max_page_size = 5
class Pager(APIView):
def get(self,request,*args,**kwargs):
# 获取所有数据
ret=models.Book.objects.all()
# 创建分页对象
page=Mypage()
# 在数据库中获取分页的数据
page_list=page.paginate_queryset(ret,request,view=self)
# 对分页进行序列化
ser=BookSerializer1(instance=page_list,many=True)
# return Response(ser.data)
# 这个也是返回Response对象,但是比基本的多了上一页,下一页,和总数据条数(了解即可)
return page.get_paginated_response(ser.data)
setting里
REST_FRAMEWORK = {
# 每页显示两条
'PAGE_SIZE':2
}
路由:
url(r'^pager/$', views.Pager.as_view()),
Serializers
class BookSerializer1(serializers.ModelSerializer):
class Meta:
model=models.Book
# fields="__all__"
exclude=('authors',)
使用方法:
- 1 导入PageNumberPagination类
- 2 实例化产生一个对象
page_pagination = PageNumberPagination() - 3 需要配置四个参数:page_size,page_query_param,page_size_query_param,max_page_size
page_size必须指定:在setting中指定或者直接赋值 - 4 调用下面的方法,返回ret数据
ret = page_pagination.paginate_queryset(book_list, request, self) - 5 再序列化,就是序列化返回的数据,也就是ret
类中需要掌握的几个属性
-page_size:控制每页显示条数
-page_query_param:控制查询第几页的查询参数,
-比如page_query_param='xx'
-http://127.0.0.1:8000/books/?xx=2 表示查询第二页的数据
-page_size_query_param:控制每页最大显示的条数
-比如page_pagination.page_size_query_param='max'
-http://127.0.0.1:8000/books/?xx=2&max=6 表示查询第二页的数据,每页显示6条
-max_page_size:控制每页最大显示的条数
-比如:page_pagination.max_page_size=7
-http://127.0.0.1:8000/books/?max=1000 最多显示7条
2、偏移分页(在第n个位置,向后查看n条数据)
使用方式:
同简单分页
重点的参数:
-default_limit:默认每页显示的条数,默认偏移的数量
-比如:default_limit=5
-http://127.0.0.1:8000/books/ 就会显示5条数据
-limit_query_param:往后偏移多少条
-就用默认值:limit
-offset_query_param:标杆值
-用默认值:offset
limit_query_param+offset_query_param联合起来用:
-访问:http://127.0.0.1:8000/books/?limit=1&offset=5 表示:以数据的第5条作为标杆,往后偏移1条
-max_limit:最大偏移的条数(最大取出的条数)
# http://127.0.0.1:8000/pager/?offset=4&limit=3
from rest_framework.pagination import LimitOffsetPagination
# 也可以自定制,同简单分页
class Pager(APIView):
def get(self,request,*args,**kwargs):
# 获取所有数据
ret=models.Book.objects.all()
# 创建分页对象
page=LimitOffsetPagination()
# 在数据库中获取分页的数据
page_list=page.paginate_queryset(ret,request,view=self)
# 对分页进行序列化
ser=BookSerializer1(instance=page_list,many=True)
# return page.get_paginated_response(ser.data)
return Response(ser.data)
3、 CursorPagination(加密分页,只能看上一页和下一页,速度快)
重点参数:
-page_size:每页显示的条数
-cursor_query_param:不需要动
-ordering:按什么排序
通过get_paginated_response返回结果中带上一页和下一页的链接地址
page_pagination.get_paginated_response(book_ser.data) 方法的用法
from rest_framework.pagination import CursorPagination
# 看源码,是通过sql查询,大于id和小于id
class Pager(APIView):
def get(self,request,*args,**kwargs):
# 获取所有数据
ret=models.Book.objects.all()
# 创建分页对象
page=CursorPagination()
page.ordering='nid'
# 在数据库中获取分页的数据
page_list=page.paginate_queryset(ret,request,view=self)
# 对分页进行序列化
ser=BookSerializer1(instance=page_list,many=True)
# 可以避免页码被猜到
return page.get_paginated_response(ser.data)
二、url控制器
1、自定义路由
from django.conf.urls import url
from app01 import views
urlpatterns = [
url(r'^books/$', views.BookView.as_view()),
url(r'^books/(?P<pk>\d+)$', views.BookDetailView.as_view()),
]
class BookView(APIView):
def get(self, request):
book_list = models.Book.objects.all()
bs = BookSerializers(book_list, many=True)
return Response(bs.data)
def post(self, request):
# 添加一条数据
print(request.data)
bs=BookSerializers(data=request.data)
if bs.is_valid():
bs.save() # 生成记录
return Response(bs.data)
else:
return Response(bs.errors)
class BookDetailView(APIView):
def get(self,request,pk):
book_obj=models.Book.objects.filter(pk=pk).first()
bs=BookSerializers(book_obj,many=False)
return Response(bs.data)
def put(self,request,pk):
book_obj = models.Book.objects.filter(pk=pk).first()
bs=BookSerializers(data=request.data,instance=book_obj)
if bs.is_valid():
bs.save() # update
return Response(bs.data)
else:
return Response(bs.errors)
def delete(self,request,pk):
models.Book.objects.filter(pk=pk).delete()
return Response("")
2、半自动路由(试图类继承ModelViewSet)
from django.conf.urls import url
from app01 import views
urlpatterns = [
url(r'^publish/$', views.PublishView.as_view({'get':'list','post':'create'})),
url(r'^publish/(?P<pk>\d+)/$', views.PublishView.as_view({'get':'retrieve','put':'update','delete':'destroy'})),
]
from rest_framework.viewsets import ModelViewSet
class PublishView(ModelViewSet):
queryset=models.Publish.objects.all()
serializer_class=PublishSerializers
3、全自动路由(自动路由生成)
from django.conf.urls import url,include
from app01 import views
from rest_framework import routers
#生成一个router对象
router=routers.DefaultRouter()
# 两个参数,一个是匹配的路由,一个是视图中写的CBV的类
router.register('publish',views.PublishView)
urlpatterns = [
# http://127.0.0.1:8000/publish/format=json(渲染器通过这个判断,返回渲染的页面)
# url(r'^publish/', views.PublishView.as_view({'get':'list','post':'create'})),
# http://127.0.0.1:8000/publish.json(渲染器通过这个判断,返回渲染的页面)
# url(r'^publish\.(?P<format>\w+)$', views.PublishView.as_view({'get':'list','post':'create'})),
# 可以用 以下方式访问
# 1 http://127.0.0.1:8000/publish/
# 2 http://127.0.0.1:8000/publish.json
# 3 http://127.0.0.1:8000/publish/3
# 4 http://127.0.0.1:8000/publish/3.json
url(r'',include(router.urls))
]
from rest_framework.viewsets import ModelViewSet
class PublishView(ModelViewSet):
queryset=models.Publish.objects.all()
serializer_class=PublishSerializers
三、响应器
1、 作用
根据 用户请求URL 或 用户可接受的类型,筛选出合适的 渲染组件。
用户请求URL:
http://127.0.0.1:8000/test/?format=json
http://127.0.0.1:8000/test.json
2、 内置渲染器
显示json格式:JSONRenderer
访问URL:
- http://127.0.0.1:8000/test/?format=json
- http://127.0.0.1:8000/test.json
- http://127.0.0.1:8000/test/
默认显示格式:BrowsableAPIRenderer(可以修改它的html文件)
访问URL:
- http://127.0.0.1:8000/test/?format=api
- http://127.0.0.1:8000/test.api
- http://127.0.0.1:8000/test/
表格方式:AdminRenderer
访问URL:
- http://127.0.0.1:8000/test/?format=admin
- http://127.0.0.1:8000/test.admin
- http://127.0.0.1:8000/test/
form表单方式:HTMLFormRenderer
访问URL:
- http://127.0.0.1:8000/test/?format=form
- http://127.0.0.1:8000/test.form
- http://127.0.0.1:8000/test/
3、局部使用
from rest_framework.renderers import HTMLFormRenderer,BrowsableAPIRenderer
class BookDetailView(APIView):
renderer_classes = [HTMLFormRenderer,BrowsableAPIRenderer ]
def get(self,request,pk):
book_obj=models.Book.objects.filter(pk=pk).first()
bs=BookSerializers(book_obj,many=False)
return Response(bs.data)
def put(self,request,pk):
book_obj = models.Book.objects.filter(pk=pk).first()
bs=BookSerializers(data=request.data,instance=book_obj)
if bs.is_valid():
bs.save() # update
return Response(bs.data)
else:
return Response(bs.errors)
def delete(self,request,pk):
models.Book.objects.filter(pk=pk).delete()
return Response("")
4、全局使用
settings里配置:
REST_FRAMEWORK = {
'DEFAULT_RENDERER_CLASSES':['rest_framework.renderers.JSONRenderer']
}
5、自定义显示模版
from rest_framework.renderers import TemplateHTMLRenderer
class BookDetailView(APIView):
renderer_classes = [TemplateHTMLRenderer]
def get(self,request,pk):
book_obj=models.Book.objects.filter(pk=pk).first()
bs=BookSerializers(book_obj,many=False)
return Response(bs.data,template_name='aa.html')
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
{{ title }}
{{ publishDate }}
</body>
</html>
注意:如果同时多个存在时,自动根据URL后缀来选择渲染器。
四、解析器
1、解析器的作用
根据请求头 content-type 选择对应的解析器对请求体内容进行处理。
有application/json,x-www-form-urlencoded,form-data等格式
2、全局使用解析器
setting里
REST_FRAMEWORK = {
'DEFAULT_PARSER_CLASSES':[
'rest_framework.parsers.JSONParser'
'rest_framework.parsers.FormParser'
'rest_framework.parsers.MultiPartParser'
]
}
路由:
urlpatterns = [
url(r'test/', TestView.as_view()),
]
视图函数:
from rest_framework.views import APIView
from rest_framework.response import Response
class TestView(APIView):
def post(self, request, *args, **kwargs):
print(request.content_type)
# 获取请求的值,并使用对应的JSONParser进行处理
print(request.data)
# application/x-www-form-urlencoded 或 multipart/form-data时,request.POST中才有值
print(request.POST)
print(request.FILES)
return Response('POST请求,响应内容')
def put(self, request, *args, **kwargs):
return Response('PUT请求,响应内容')
3、局部使用解析器
a. 仅处理请求头content-type为application/json的请求体
from django.conf.urls import url, include
from web.views.s5_parser import TestView
urlpatterns = [
url(r'test/', TestView.as_view(), name='test'),
]
#!/usr/bin/env python
# -*- coding:utf-8 -*-
from rest_framework.views import APIView
from rest_framework.response import Response
from rest_framework.request import Request
from rest_framework.parsers import JSONParser
class TestView(APIView):
parser_classes = [JSONParser, ]
def post(self, request, *args, **kwargs):
print(request.content_type)
# 获取请求的值,并使用对应的JSONParser进行处理
print(request.data)
# application/x-www-form-urlencoded 或 multipart/form-data时,request.POST中才有值
print(request.POST)
print(request.FILES)
return Response('POST请求,响应内容')
def put(self, request, *args, **kwargs):
return Response('PUT请求,响应内容')
b. 仅处理请求头content-type为application/x-www-form-urlencoded 的请求体
from django.conf.urls import url, include
from web.views import TestView
urlpatterns = [
url(r'test/', TestView.as_view(), name='test'),
]
#!/usr/bin/env python
# -*- coding:utf-8 -*-
from rest_framework.views import APIView
from rest_framework.response import Response
from rest_framework.request import Request
from rest_framework.parsers import FormParser
class TestView(APIView):
parser_classes = [FormParser, ]
def post(self, request, *args, **kwargs):
print(request.content_type)
# 获取请求的值,并使用对应的JSONParser进行处理
print(request.data)
# application/x-www-form-urlencoded 或 multipart/form-data时,request.POST中才有值
print(request.POST)
print(request.FILES)
return Response('POST请求,响应内容')
def put(self, request, *args, **kwargs):
return Response('PUT请求,响应内容')
c. 仅处理请求头content-type为multipart/form-data的请求体
from django.conf.urls import url, include
from web.views import TestView
urlpatterns = [
url(r'test/', TestView.as_view(), name='test'),
]
#!/usr/bin/env python
# -*- coding:utf-8 -*-
from rest_framework.views import APIView
from rest_framework.response import Response
from rest_framework.request import Request
from rest_framework.parsers import MultiPartParser
class TestView(APIView):
parser_classes = [MultiPartParser, ]
def post(self, request, *args, **kwargs):
print(request.content_type)
# 获取请求的值,并使用对应的JSONParser进行处理
print(request.data)
# application/x-www-form-urlencoded 或 multipart/form-data时,request.POST中才有值
print(request.POST)
print(request.FILES)
return Response('POST请求,响应内容')
def put(self, request, *args, **kwargs):
return Response('PUT请求,响应内容')
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<form action="http://127.0.0.1:8000/test/" method="post" enctype="multipart/form-data">
<input type="text" name="user" />
<input type="file" name="img">
<input type="submit" value="提交">
</form>
</body>
</html>
d. 仅上传文件
from django.conf.urls import url, include
from web.views import TestView
urlpatterns = [
url(r'test/(?P<filename>[^/]+)', TestView.as_view(), name='test'),
]
#!/usr/bin/env python
# -*- coding:utf-8 -*-
from rest_framework.views import APIView
from rest_framework.response import Response
from rest_framework.request import Request
from rest_framework.parsers import FileUploadParser
class TestView(APIView):
parser_classes = [FileUploadParser, ]
def post(self, request, filename, *args, **kwargs):
print(filename)
print(request.content_type)
# 获取请求的值,并使用对应的JSONParser进行处理
print(request.data)
# application/x-www-form-urlencoded 或 multipart/form-data时,request.POST中才有值
print(request.POST)
print(request.FILES)
return Response('POST请求,响应内容')
def put(self, request, *args, **kwargs):
return Response('PUT请求,响应内容')
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<form action="http://127.0.0.1:8000/test/f1.numbers" method="post" enctype="multipart/form-data">
<input type="text" name="user" />
<input type="file" name="img">
<input type="submit" value="提交">
</form>
</body>
</html>
e. 同时多个Parser
当同时使用多个parser时,rest framework会根据请求头content-type自动进行比对,并使用对应parser
from django.conf.urls import url, include
from web.views import TestView
urlpatterns = [
url(r'test/', TestView.as_view(), name='test'),
]
#!/usr/bin/env python
# -*- coding:utf-8 -*-
from rest_framework.views import APIView
from rest_framework.response import Response
from rest_framework.request import Request
from rest_framework.parsers import JSONParser, FormParser, MultiPartParser
class TestView(APIView):
parser_classes = [JSONParser, FormParser, MultiPartParser, ]
def post(self, request, *args, **kwargs):
print(request.content_type)
# 获取请求的值,并使用对应的JSONParser进行处理
print(request.data)
# application/x-www-form-urlencoded 或 multipart/form-data时,request.POST中才有值
print(request.POST)
print(request.FILES)
return Response('POST请求,响应内容')
def put(self, request, *args, **kwargs):
return Response('PUT请求,响应内容')
4、源码分析
1 在调用request.data时,才进行解析,由此入手
@property
def data(self):
if not _hasattr(self, '_full_data'):
self._load_data_and_files()
return self._full_data
2 查看self._load_data_and_files()方法---->self._data, self._files = self._parse()
def _parse(self):
#用户请求头里content_type的值
media_type = self.content_type
#self.parsers 就是用户配置的parser_classes = [FileUploadParser,FormParser ]
#self里就有content_type,传入此函数
parser = self.negotiator.select_parser(self, self.parsers)
3 查看self.negotiator.select_parser(self, self.parsers)
def select_parser(self, request, parsers):
#同过media_type和request.content_type比较,来返回解析器,然后调用解析器的解析方法
#每个解析器都有media_type = 'multipart/form-data'属性
for parser in parsers:
if media_type_matches(parser.media_type, request.content_type):
return parser
return None
4 最终调用parser的解析方法来解析parsed = parser.parse(stream, media_type, self.parser_context)
1 Request实例化,parsers=self.get_parsers()
Request(
request,
parsers=self.get_parsers(),
authenticators=self.get_authenticators(),
negotiator=self.get_content_negotiator(),
parser_context=parser_context
)
2 get_parsers方法,循环实例化出self.parser_classes中类对象
def get_parsers(self):
return [parser() for parser in self.parser_classes]
3 self.parser_classes 先从类本身找,找不到去父类找即APIVIew 中的
parser_classes = api_settings.DEFAULT_PARSER_CLASSES
4 api_settings是一个对象,对象里找DEFAULT_PARSER_CLASSES属性,找不到,会到getattr方法
def __getattr__(self, attr):
if attr not in self.defaults:
raise AttributeError("Invalid API setting: '%s'" % attr)
try:
#调用self.user_settings方法,返回一个字典,字典再取attr属性
val = self.user_settings[attr]
except KeyError:
# Fall back to defaults
val = self.defaults[attr]
# Coerce import strings into classes
if attr in self.import_strings:
val = perform_import(val, attr)
# Cache the result
self._cached_attrs.add(attr)
setattr(self, attr, val)
return val
5 user_settings方法 ,通过反射去setting配置文件里找REST_FRAMEWORK属性,找不到,返回空字典
@property
def user_settings(self):
if not hasattr(self, '_user_settings'):
self._user_settings = getattr(settings, 'REST_FRAMEWORK', {})
return self._user_settings