Django路由与视图¶

路由说白了就是视图(函数)的对应关系,一个路由对应一个视图,如上面文章所提到的,当打开/users/路径的时候会让users这个函数来进行逻辑处理,把处理的结果再返回到前端

路由的配置文件入口在 settings.py 文件中已经定义.

ROOT_URLCONF = 'yang.urls'

路由¶

路由的配置¶

绝对地址访问¶

# 访问地址必须是http://127.0.0.1:8000/hello/
url(r'^hello/$', views.hello),

使用正则与分组¶

# http://127.0.0.1:8000/detail-2-2.html
# url(r'^detail-(\d+)-(\d+).html', views.detail),
# 括号内匹配到的内容会当做参数传给detail函数
def detail(request, nid, uid):
    print(nid, uid)
    return HttpResponse(nid)

# 分组匹配
# url(r'^detail-(?P<uid>\d+)-(?P<nid>\d+).html', views.detail),
# 使用 *args, **kwargs 接受所有参数
def detail(request, *args, **kwargs):
    print(nid, uid)
    return HttpResponse(nid)

在函数内需要接受year,month,day参数

url(r'^(?P<year>[0-9]{4})/(?P<month>[0-9]{2})/(?P<day>[0-9]{2})/$', views.date),
# 使用分组匹配就不用考虑视图函数的参数位置了

date视图必须接收以下参数

def date(request, year, month, day):

访问地址为: http://127.0.0.1:8000/2017/3/14/

传值¶

url(r'^(?P<year>[0-9]{4})/$', views.id, {'foo': 'bar'}),

id函数必须接受year和foo参数

别名¶

对URL路由关系进行命名,以后可以通过此名字获取URL(通过别名获取URL,就算URL调整也不会影响之前所有的别名)

可用于前端的from表单验证,如下实例,URLs地址的时候,因为from表单提交的地址使用了别名,所以会自动替换

# urls.py
from django.conf.urls import url
from app01 import views
urlpatterns = [
    url(r'^index/$', views.index, name='bieming'),
]

# views.py
from django.shortcuts import render,HttpResponse
def index(request):
    if request.method=='POST':
        username=request.POST.get('username')
        password=request.POST.get('password')
        if username=='as' and password=='123':
            return HttpResponse("登陆成功")
    return render(request, 'index.html')

# index.html
<form action="{% url 'bieming' %}" method="post">
     用户名:<input type="text" name="username">
     密码:<input type="password" name="password">
     <input type="submit" value="submit">
</form>

CBV¶

url(r'^home/', views.Home.as_view()),

路由分发¶

include分发,有利于解耦

# 当访问二级路由是cmdb的时候转发给app01.urls处理
url(r'^cmdb/$', include('app01.urls')),

路由分发实例¶

可以使用incloud把很多个路由进行拆封,然后把不同的业务放到不同的urls中,首先我们创建项目及应用

# 创建DjangoProjects项目
django-admin.py startproject DjangoProjects
cd DjangoProjects
# 在项目内创建app1和app2应用
python3 manage.py startapp app1
python3 manage.py startapp app2

项目的urls.py文件内容

# DjangoProjects/DjangoProjects/urls.py
from django.conf.urls import url, include
from django.contrib import admin
urlpatterns = [
    # 当路由匹配到一级路径为app1时，就把这个URL交给app1.urls再次进行匹配
    url(r'^app1/', include('app1.urls')),
    url(r'^app2/', include('app2.urls')),
]

应用urls.py和view.py文件内容

# DjangoProjects/app1/urls.py
from django.conf.urls import url,include
from django.contrib import admin
from app1 import views
urlpatterns = [
    url(r'^hello/$', views.hello),
]
# DjangoProjects/app1/views.py
from django.shortcuts import render,HttpResponse
def hello(request):
    return HttpResponse("Hello App1")
# DjangoProjects/app2/urls.py
from django.conf.urls import url
from django.contrib import admin
from app2 import views
urlpatterns = [
    url(r'^hello/$', views.hello),
]
# DjangoProjects/app2/views.py
from django.shortcuts import render,HttpResponse
def hello(request):
    return HttpResponse("Hello App2")

当访问 http://127.0.0.1:8000/app1/hello/ 时返回内容 Hello App1
当访问 http://127.0.0.1:8000/app2/hello/ 时返回内容 Hello App2

视图¶

FBV & CBV¶

Django两者都支持

function base view
class base view

请求与响应¶

http请求: HttpRequest对象

http响应: HttpResponse对象

HttpRequest对象属性

属性	描述
request.path	请求页面的路径,不包括域名
request.path_info	可用于跳转到当前页面
request.get_full_path()	获取带参数的路径
request.method	页面的请求方式
request.GET	GET请求方式的数据
request.POST	POST请求方式的数据

HttpResponse对象属性

属性	描述
render(request, ‘index.html’)	返回一个模板页面
render_to_response( ‘index.html’)	返回一个模板页面
redirect(‘/login’)	页面跳转
HttpResponseRedirect(‘/login’)	页面跳转
HttpResponse(‘yang’)	给页面返回一个字符串

简单实例¶

创建项目¶

➜  django_xxx git:(master) ✗ django-admin startproject mysite
➜  django_xxx git:(master) ✗ cd mysite
➜  mysite git:(master) ✗ tree
.
├── manage.py
└── mysite
    ├── __init__.py
    ├── settings.py
    ├── urls.py
    └── wsgi.py

1 directory, 5 files

创建app¶

新建app,名称为learn,会自动生成一个learn目录

➜  mysite git:(master) ✗ python3 manage.py startapp learn
➜  mysite git:(master) ✗ tree
.
├── learn
│   ├── __init__.py
│   ├── admin.py
│   ├── apps.py    # Django 1.9.x 以上会在Django 1.8基础上多出此文件
│   ├── migrations # Django 1.8.x 以上会生成此目录
│   │   └── __init__.py
│   ├── models.py
│   ├── tests.py
│   └── views.py
├── manage.py
└── mysite
    ├── __init__.py
    ├── __pycache__
    │   ├── __init__.cpython-35.pyc
    │   └── settings.cpython-35.pyc
    ├── settings.py
    ├── urls.py
    └── wsgi.py

4 directories, 14 files

将新定义的app添加到settings.py中的INSTALL_APPS中¶

➜  mysite git:(master) ✗ ls
learn     manage.py mysite
➜  mysite git:(master) ✗ vim mysite/settings.py

# 修改内容如下

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'learn',
]

定义视图函数¶

➜  mysite git:(master) ✗ vim learn/views.py

from django.shortcuts import render

# Create your views here.
from django.http import HttpResponse

def index(request):
    return HttpResponse('Hello World')

定义视图函数相关的url¶

即规定访问什么网址对应什么内容

Django 1.8.x以后,官方要求以如下方式导入,再使用

from learn.views import index   # 导入

urlpatterns = [
    url(r'^admin/', admin.site.urls),
    url(r'^$', index),   # 使用index
]

运行¶

python manage.py runserver

打开 http://127.0.0.1:8000/ 即可看到效果,页面会显示 Hello World

如需修改监听IP,及端口

python manage.py runserver 0.0.0.0:8000

视图及url进阶¶

通过url传值,做加减法

/add?a=4&b=5¶

url 通过 /add?a=4&b=5方式传值

➜  mysite git:(master) ✗ ls
db.sqlite3 learn      manage.py  mysite
➜  mysite git:(master) ✗ python3 manage.py startapp calc

➜  mysite git:(master) ✗ tree calc
calc
├── __init__.py
├── admin.py
├── apps.py
├── migrations
│   └── __init__.py
├── models.py
├── tests.py
└── views.py

1 directory, 7 files

将 calc 这个app加入到 mysite/settings.py

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    ...
    'calc',
]

修改 calc/views.py

➜  mysite git:(master) ✗ vim calc/views.py

from django.shortcuts import render

# Create your views here.
from django.http import HttpResponse

def add(request):
    a = request.GET['a']
    b = request.GET['b']
    c = int(a) + int(b)
    return HttpResponse(str(c))

request.GET 类似于一个字典，更好的办法是用 request.GET.get(‘a’, 0) 当没有传递 a 的时候默认 a 为 0

修改 mysite/urls.py

➜  mysite git:(master) ✗ vim mysite/urls.py

from django.conf.urls import url
from django.contrib import admin
from learn.views import index
from calc.views import add

urlpatterns = [
    url(r'^admin/', admin.site.urls),
    url(r'^$', index),
    url(r'^add/$',add,name='add'),
]

运行

➜  mysite git:(master) ✗ python3 manage.py runserver

访问

http://127.0.0.1:8000/add/?a=4&b=5

会显示 a + b 的结果

试试 http://127.0.0.1:8000/add/?a=157&b=5

/add/3/4/¶

url 通过 /add/3/4/ 传值

修改 calc/views.py

vim calc/views.py

def add2(request,a,b):
    c = int(a) + int(b)
    return HttpResponse(str(c))

修改 mysite/urls.py

url(r'^add/(\d+)/(\d+)/$',add2,name='add2'),

访问 http://127.0.0.1:8000/add/100/200/

新地址自动跳转到旧地址的一种方式:

from django.http import HttpResponseRedirect
# from django.core.urlresolvers import reverse  # django 1.4.x - django 1.10.x
from django.urls import reverse

def old_add2_redirect(request,a,b):
    return HttpResponseRedirect(reverse('add2',args=(a,b)))

urls.py

url(r'^new_add/(\d+)/(\d+)/$',add2,name='add2'),
url(r'^add/(\d+)/(\d+)/$',old_add2_redirect),