Django -- URLconf 配置技巧
本章我们将对视图和URL配置使用一些高超的小技巧。
【流线型化函数导入(streamlining)】
方法一:传统方法
from django.conf.urls.defaults import * from mysite.views import hello, current_datetime, hours_ahead urlpatterns = patterns('', (r'^hello/$', hello), (r'^time/$', current_datetime), (r'^time/plus/(\d{1,2})/$', hours_ahead), )
方法二:导入views函数,维护较简单,针对import的视图模块
from django.conf.urls.defaults import * **from mysite import views** urlpatterns = patterns('', (r'^hello/$', views.hello'), (r'^time/$', views.current_datetime ), (r'^time/plus/(d{1,2})/$', views.hours_ahead ), )
方法三:导入模块名和视图函数名,注意用引号括起来
from django.conf.urls.defaults import * urlpatterns = patterns('', (r'^hello/$', 'mysite.views.hello' ), (r'^time/$', 'mysite.views.current_datetime' ), (r'^time/plus/(d{1,2})/$', 'mysite.views.hours_ahead' ), )
方法四:提取公共视图前缀,不要再前缀后面和视图字符串前面放点号,django会自动处理
from django.conf.urls.defaults import * urlpatterns = patterns('mysite.views' , (r'^hello/$', 'hello' ), (r'^time/$', 'current_datetime' ), (r'^time/plus/(d{1,2})/$', 'hours_ahead' ), )
方法四(2):如果我们URLconf没有一个公共前缀时呢?如下
from django.conf.urls.defaults import * urlpatterns = patterns('', (r'^hello/$', 'mysite.views.hello'), (r'^time/$', 'mysite.views.current_datetime'), (r'^time/plus/(\d{1,2})/$', 'mysite.views.hours_ahead'), (r'^tag/(\w+)/$', 'weblog.views.tag'), )
解决:整个框架关注的是urlpatterns模块级别的变量,patterns返回对象是可相加的。
from django.conf.urls.defaults import * urlpatterns = patterns('mysite.views', (r'^hello/$', 'hello'), (r'^time/$', 'current_datetime'), (r'^time/plus/(\d{1,2})/$', 'hours_ahead'), ) urlpatterns += patterns('weblog.views', (r'^tag/(\w+)/$', 'tag'), )
特例:django调试模式下修改URLconf的行为技术,链接debuginfo只在DEBUG配置项为True时才有效。
from django.conf import settings from django.conf.urls.defaults import * from mysite import views urlpatterns = patterns('', ..... ) if settings.DEBUG: urlpatterns += patterns('', (r'^debuginfo/$', views.debug), )
【url的命名法匹配模式】
方法一:使用命名组,好比python函数中位置参数和关键字参数的对应关系,其语法 (?P<组名字>匹配模式)。
## 传统方法 from django.conf.urls.defaults import * from mysite import views urlpatterns = patterns('', (r'^articles/(\d{4})/$', views.year_archive), (r'^articles/(\d{4})/(\d{2})/$', views.month_archive), ) ## 使用命名组 from django.conf.urls.defaults import * from mysite import views urlpatterns = patterns('', (r'^articles/(?P<year>\d{4})/$', views.year_archive), (r'^articles/(?P<year>\d{4})/(?P<month>\d{2})/$', views.month_archive), )
为了区分它们的区别,以请求/archive/2016/12为例,函数都进行了怎样的调用?
前者:month_archive(request, '2016', '12')
后者:month_archive(request, year='2016', month='12')
缺点:虽然这样可读性强了,而且更准确了,但是冗余性也变差了;而且一个URLconf模式中不允许同时存在命名组和非命名组格式,优先顺序:命名组>非命名组>关键字传递额外参数。
【传递额外参数信息】
在我们写的视图函数中,我们会发现有好多视图函数类似,但又有不同,我们怎么样才能将它写的更简洁,原始模板如下:
# urls.py from django.conf.urls.defaults import * from mysite import views urlpatterns = patterns('', (r'^foo/$', views.foo_view), (r'^bar/$', views.bar_view), ) # views.py from django.shortcuts import render_to_response from mysite.models import MyModel def foo_view(request): m_list = MyModel.objects.filter(is_new=True) return render_to_response('template1.html', {'m_list': m_list}) def bar_view(request): m_list = MyModel.objects.filter(is_new=True) return render_to_response('template2.html', {'m_list': m_list})
方法一:添加if 判断,缺点还是把url耦合到代码里了,更改url的话还得去改视图函数。
# views.py from django.shortcuts import render_to_response from mysite.models import MyModel def foobar_view(request, url): m_list = MyModel.objects.filter(is_new=True) if url == 'foo': template_name = 'template1.html' elif url == 'bar': template_name = 'template2.html' return render_to_response(template_name, {'m_list': m_list})
方法二:URLconf中包含第三个位置参数:关键字参数
# urls.py from django.conf.urls.defaults import * from mysite import viewsurlpatterns = patterns('', (r'^foo/$', views.foobar_view, {'template_name': 'template1.html'}), (r'^bar/$', views.foobar_view, {'template_name': 'template2.html'}), ) # views.py from django.shortcuts import render_to_response from mysite.models import MyModel def foobar_view(request, template_name): m_list = MyModel.objects.filter(is_new=True) return render_to_response(template_name, {'m_list': m_list})
举例:我们要访问如下规则的url
/mydata/jan/01/
/mydata/jan/02/
/mydata/jan/03/
# ...
/mydata/dec/30/
/mydata/dec/31/
我们可以设置URLconf 和 视图函数如下:
urlpatterns = patterns('',
(r'^mydata/(?P<month>\w{3})/(?P<day>\d\d)/$', views.my_view),
)
def my_view(request, month, day):
# ....
但当如果我们想增加访问一个/mydata/birthday/的url,正常我们要给他一个视图函数,但我们可以用上面传递额外参数解决
urlpatterns = patterns('',
(r'^mydata/birthday/$', views.my_view, {'month': 'jan', 'day': '06'}),
(r'^mydata/(?P<month>\w{3})/(?P<day>\d\d)/$', views.my_view),
)
【include其他URLconf】
有时我们希望我们的代码用于多个django站点,于是我们就要考虑将我们的URLconf以包含的方式处理。
from django.conf.urls.defaults import * urlpatterns = patterns('', (r'^weblog/', include('mysite.blog.urls')), (r'^photos/', include('mysite.photos.urls')), (r'^about/$', 'mysite.views.about'), )
注:在包含其他urls的url没有$符,但包含有/,他的意思是当django遇到include,它将截断匹配的URL,把剩余的字符串发往包含的URLconf进一步处理。
比如我们访问/weblog/2007/ weblog被此URLconf匹配,/ 截断的2007就交给了包含的URLconf中的urls。
1、捕获的参数与include
# root urls.py from django.conf.urls.defaults import * urlpatterns = patterns('', (r'^(?P<username>\w+)/blog/', include('foo.urls.blog')), ) # foo/urls/blog.py from django.conf.urls.defaults import * urlpatterns = patterns('', (r'^$', 'foo.views.blog_index'), (r'^archive/$', 'foo.views.blog_archive'), )
本例中,被捕获的username变量将传递给被包含的URLconf,进而传递给那个URLconf中每一个视图函数。
2、额外的URLconf与include
就像上边提到的,URLconf有一个第三位置的参数,用字典表示,即下面两个配置时等效的:
# urls.py from django.conf.urls.defaults import * urlpatterns = patterns('', (r'^blog/', include('inner'), {'blogid': 3}), ) # inner.py from django.conf.urls.defaults import * urlpatterns = patterns('', (r'^archive/$', 'mysite.views.archive'), (r'^about/$', 'mysite.views.about'), (r'^rss/$', 'mysite.views.rss'), )
# urls.py from django.conf.urls.defaults import * urlpatterns = patterns('', (r'^blog/', include('inner')), ) # inner.py from django.conf.urls.defaults import * urlpatterns = patterns('', (r'^archive/$', 'mysite.views.archive', {'blogid': 3}), (r'^about/$', 'mysite.views.about', {'blogid': 3}), (r'^rss/$', 'mysite.views.rss', {'blogid': 3}), )