自定义django class based view 的一个例子

By：Roy.LiuLast updated：2014-05-22

Django 从 1.3 版本开始进引入了 class based view 的方式，以这种方式处理视图，可以在一些基类中写一些公用方法。我查看 Django 相关文档，感觉有点麻烦。其实如果要将现有的基于 function 的 view 变成 class based view 应该是比较简单的。完全可以自定义个实现。虽然这不是 django 所要求的方式，但对我来说，这样的改动也许是最小的。举个例子
原来的处理方法如下，这是基于 function 的 view

    def index(self, request, *args, **kwargs):
        return render_to_response('index.html',{},context_instance=RequestContext(request))


    def get(self, request, *args, **kwargs):
        print 'execute get methos'
        print kwargs
        context = {}
        return render_to_response('get.html',context,context_instance=RequestContext(request))

url 的配置:

urlpatterns = patterns('',
    url(r'^$', views.index),
    url(r'^restview/(?P\d{1,15}).html$',views.get ),
    url(r'^restview/head.html$',views.head ),     
)

以上是传统的配置方式，如果要变成 class based view 最简单的方法是什么样的呢，就目前来说，我觉得如下方法或许是最简单的，改动也最小的. 总结为如下:
视图view class 的代码

'''
Created on 2014-5-22
@author: Administrator
'''
from django import http
from django.shortcuts import render_to_response
from django.template.context import RequestContext

class RestView(object):
    methods = ('GET', 'HEAD', 'INDEX')

    @classmethod
    def dispatch(cls, request, *args, **kwargs):       
        print kwargs
        exec_method = kwargs.get('method','')
        resource = cls()
        if exec_method.lower() not in (method.lower() for method in resource.methods):
            return http.HttpResponseNotAllowed(resource.methods)
        try:
            method = getattr(resource, exec_method.lower())
        except AttributeError:
            raise Exception("View method `%s` does not exist." % exec_method.lower())
        if not callable(method):
            raise Exception("View method `%s` is not callable." % exec_method.lower())
        return method(request, *args, **kwargs)
    
    def index(self, request, *args, **kwargs):
        return render_to_response('index.html',{},context_instance=RequestContext(request))


    def get(self, request, *args, **kwargs):
        print 'execute get methos'
        print kwargs
        context = {}
        return render_to_response('get.html',context,context_instance=RequestContext(request))

    def head(self, request, *args, **kwargs):
        print 'execute head method'
        response = self.get(request, *args, **kwargs)
        response.content = 'head method testing'
        return response

同样 urls.py 的配置也要相应改变

from django.conf.urls import patterns, include, url
from views import RestView
# Uncomment the next two lines to enable the admin:
# from django.contrib import admin
# admin.autodiscover()
urlpatterns = patterns('',
    url(r'^$', RestView.dispatch, {"method":"index"}),
    url(r'^restview/(?P\d{1,15}).html$', RestView.dispatch, {"method":"get"} ),
    url(r'^restview/head.html$', RestView.dispatch, {"method":"head"} ),   
  
)

在这样的配置之后，运行程序，可以看到如下界面,说明成功运行，并且找到各自的方法，而且改动并不大，只是将原来的方法放到一个类中就可以了。