Ubuntu12.04系统下写你的第一个Django1.5应用(三)--view

Ubuntu12.04系统下写你的第一个Django1.5应用(三)--view

写你的第一个视图函数:

第一步,编写视图函数:

jiangge@ubuntu:~/mysite/polls$ vim views.py 

加入以下内容:

#coding:utf-8from django.http import HttpResponsedef index(request):    return HttpResponse("Hello, world. You are at the poll index.")

第二步,ULRConf:

在polls目录下创建urls.py文件,填写以下内容:

from django.conf.urls import patterns, urlfrom polls import viewsurlpatterns = patterns('',    url(r'^$', views.index, name='index'))

现在你的app目录是这个样子的:

jiangge@ubuntu:~/mysite$ tree polls/polls/├── admin.py├── __init__.py├── models.py├── tests.py├── urls.py└── views.py0 directories, 6 files

第三步:to point the root URLconf at the polls.urls module. Inmysite/urls.py insert aninclude()

from django.conf.urls import patterns, include, urlfrom django.contrib import adminadmin.autodiscover()urlpatterns = patterns('',     url(r'^polls/', include('polls.urls')),     url(r'^admin/', include(admin.site.urls)),)

第四步:浏览器地址栏输入:

http://localhost:8000/polls/

可以看到 Hello, world. You are at the poll index. 显示出来了.

Note:

  url()方法第一个参数,regular expression 匹配.

  Note that these regular expressions do not search GET and POST parameters, or the domain name. For example, in a request tohttp://www.example.com/myapp/, the URLconf will look for myapp/. In a request tohttp://www.example.com/myapp/?page=3, the URLconf willalso look formyapp/.

  url()方法第二个参数:view 视图函数

  url()方法第三个参数:kwargs(可选的)

  url()方法第三个参数:name(可选的)

写更多的视图函数

jiangge@ubuntu:~/mysite$ vim polls/views.py

#coding:utf-8from django.http import HttpResponsedef index(request):    return HttpResponse("Hello, world. You are at the poll index.")def detail(request, poll_id):    return HttpResponse("You're looking at poll %s." % poll_id)def results(request, poll_id):    return HttpResponse("You're looking at the results of poll %s." % poll_id)def vote(request, poll_id):    return HttpResponse("You're voting on poll %s." % poll_id)

修改urls:

jiangge@ubuntu:~/mysite$ vim polls/urls.py

from django.conf.urls import patterns, urlfrom polls import viewsurlpatterns = patterns('',    # ex: /polls/    url(r'^$', views.index, name='index'),        # ex: /polls/5/    url(r'^(?P<poll_id>\d+)/$', views.detail, name='detail'),        # ex: /polls/5/results/    url(r'^(?P<poll_id>\d+)/results/$', views.results, name='results'),        # ex: /polls/5/vote/    url(r'^(?P<poll_id>\d+)/vote/$', views.vote, name='vote'),)

浏览器分别访问:

http://localhost:8000/polls/34/

显示结果:You're looking at poll 34.

http://localhost:8000/polls/34/results/

显示结果:You're looking at the results of poll 34.

http://localhost:8000/polls/34/vote/

显示结果:You're voting on poll 34.

Write views that actually do something

#coding:utf-8from django.http import HttpResponsefrom polls.models import Polldef index(request):    latest_poll_list = Poll.objects.order_by('-pub_date')[:5]    output = ', '.join([p.question for p in latest_poll_list])    return HttpResponse(output)def detail(request, poll_id):    return HttpResponse("You're looking at poll %s." % poll_id)def results(request, poll_id):    return HttpResponse("You're looking at the results of poll %s." % poll_id)def vote(request, poll_id):    return HttpResponse("You're voting on poll %s." % poll_id)

页面的设计是在view中写死的(硬代码),以后要修改会引起不必要的麻烦.

所以考虑将其分开写.

在polls目录下创建templates目录:

jiangge@ubuntu:~/mysite/polls$ mkdir templates

Note:(polls/templates) rather than the project’s (templates)

在polls/templates目录下创建polls目录

jiangge@ubuntu:~/mysite/polls/templates$ mkdir polls

在新创建的polls目录下创建index.html

Note:your template should be at polls/templates/polls/index.html.Because of how theapp_directoriestemplate loader works as described above, you can refer to this template within Django simply aspolls/index.html.  这体现了,Django 模板命名空间的思想哦.

把以下内容下入文件:

jiangge@ubuntu:~/mysite/polls/templates/polls$ vim index.html

{% if latest_poll_list %}    <ul>    {% for poll in latest_poll_list %}        <li><a href="/polls/{{ poll.id }}/">{{ poll.question }}</a></li>    {% endfor %}    </ul>{% else %}    <p>No polls are available.</p>{% endif %}

在index视图函数中使用上述模板文件:

jiangge@ubuntu:~/mysite$ vim polls/views.py

#coding:utf-8from django.http import HttpResponsefrom django.template import Context, loaderfrom polls.models import Polldef index(request):    latest_poll_list = Poll.objects.order_by('-pub_date')[:5]    template = loader.get_template('polls/index.html')    context = Context({        'latest_poll_list': latest_poll_list,    })    return HttpResponse(template.render(context))def detail(request, poll_id):    return HttpResponse("You're looking at poll %s." % poll_id)def results(request, poll_id):    return HttpResponse("You're looking at the results of poll %s." % poll_id)def vote(request, poll_id):    return HttpResponse("You're voting on poll %s." % poll_id)

一个快捷方式: render()

jiangge@ubuntu:~/mysite$ vim polls/views.py

#coding:utf-8from django.http import HttpResponsefrom django.template import Context, loaderfrom polls.models import Pollfrom django.shortcuts import renderdef index(request):    latest_poll_list = Poll.objects.all().order_by('-pub_date')[:5]    context = {'latest_poll_list': latest_poll_list}    return render(request, 'polls/index.html', context)def detail(request, poll_id):    return HttpResponse("You're looking at poll %s." % poll_id)def results(request, poll_id):    return HttpResponse("You're looking at the results of poll %s." % poll_id)def vote(request, poll_id):    return HttpResponse("You're voting on poll %s." % poll_id)

404error页面:

jiangge@ubuntu:~/mysite$ vim polls/views.py

#coding:utf-8from django.http import HttpResponsefrom django.template import Context, loaderfrom polls.models import Pollfrom django.shortcuts import renderfrom django.http import Http404def index(request):    latest_poll_list = Poll.objects.all().order_by('-pub_date')[:5]    context = {'latest_poll_list': latest_poll_list}    return render(request, 'polls/index.html', context)def detail(request, poll_id):    try:        poll = Poll.objects.get(pk=poll_id)    except Poll.DoesNotExist:        raise Http404    return render(request, 'polls/detail.html', {'poll': poll})def results(request, poll_id):    return HttpResponse("You're looking at the results of poll %s." % poll_id)def vote(request, poll_id):    return HttpResponse("You're voting on poll %s." % poll_id)

编写模板文件:

jiangge@ubuntu:~/mysite/polls/templates/polls$ vim detail.html

{{ poll }}

A shortcut: get_object_or_404():

#coding:utf-8from django.http import HttpResponsefrom django.template import Context, loaderfrom polls.models import Pollfrom django.shortcuts import render, get_object_or_404def index(request):    latest_poll_list = Poll.objects.all().order_by('-pub_date')[:5]    context = {'latest_poll_list': latest_poll_list}    return render(request, 'polls/index.html', context)def detail(request, poll_id):    poll = get_object_or_404(Poll, pk=poll_id)    return render(request, 'polls/detail.html', {'poll': poll})sdef results(request, poll_id):    return HttpResponse("You're looking at the results of poll %s." % poll_id)def vote(request, poll_id):    return HttpResponse("You're voting on poll %s." % poll_id)

再次编写detail.html模板文件:

jiangge@ubuntu:~/mysite/polls/templates/polls$ vim detail.html

<h1>{{ poll.question }}</h1><ul>{% for choice in poll.choice_set.all %}    <li>{{ choice.choice_text }}</li>{% endfor %}</ul>

移除模板中的URLs硬代码(Removing hardcoded URLs in templates)

参考文献:官方文档 https://docs.djangoproject.com/en/1.5/intro/tutorial03/点击打开链接