django3-视图函数进阶

1.视图函数的分类

　　FBV(fucntion base view)

　　CBV(class base view) ,CBV根据定义的方法名 ,判断什么请求执行什么函数

 

2.FBV转换CBV (不太对劲)

　　在CBV的url中指定执行类名.as_view()方法 ,根据源码得知dispatch函数中执行了我们自定义的类中方法 !

####################FBV
def pressedit(request, edit_id, test_id):
    obj = models.presslist.objects.get(pk=edit_id)
    print(test_id, edit_id)
    msg = ''
    if request.method == 'POST':
        obj.name = request.POST.get('pressname')

        if models.presslist.objects.filter(name=obj.name):
            msg = '已存在'

        if not obj.name:
            msg = '不能为空'

        if not models.presslist.objects.filter(name=obj.name) and obj.name:
            obj.save()

            return redirect(reverse('presslist'))
    return render(request, 'cbsadd-edit.html', {'obj': obj, 'msg': msg})
#######################CBV
class pressedit1(View):
    def get(self, request, edit_id, test_id):
        obj = models.presslist.objects.get(pk=edit_id)
        msg = ''
        print(edit_id, test_id)
        print(id(obj))

        return render(request, 'cbsadd-edit.html', {'obj': obj, 'msg': msg})

    def post(self, request, edit_id, test_id):
        msg = ''
        obj = models.presslist.objects.get(pk=edit_id)
        obj.name = request.POST.get('pressname')
        print(id(obj))
        if models.presslist.objects.filter(name=obj.name):
            msg = '已存在'

        if not obj.name:
            msg = '不能为空'

        if not models.presslist.objects.filter(name=obj.name) and obj.name:
            obj.save()

            return redirect(reverse('presslist'))
        return render(request, 'cbsadd-edit.html', {'obj': obj, 'msg': msg})

 

3.视图函数使用装饰器

import time
import functools
from django.utils.decorators import method_decorator

def wapp(func):
    @functools.wraps(func)
    def inner(*args, **kwargs):
        time1 = time.time()
        ret = func(*args, **kwargs)
        print(time.time() - time1)
        return ret

    return inner

#######FBV
#url

url(r'^press/edit/(?P<edit_id>\d+)/(?P<test_id>\d+)/', views.pressedit, name='pressedit'),

#views
@wapp
def presslist(request):
    msg_all = models.presslist.objects.all()
    return render(request, 'cbs.html', {'msg': msg_all})


#######CBV
#url

url(r'^press/edit/(?P<edit_id>\d+)/(?P<test_id>\d+)/', views.pressedit1.as_view(), name='pressedit'),

　#views

@method_decorator(wapp, name='get')　　　　###通过method_decorator这个装饰器指定自己的装饰器 和要装饰的函数 ,可以直接作用dispatch函数,对所有函数生效
class pressedit1(View):

    def get(self, request, edit_id, test_id, msg=''):
        obj = models.presslist.objects.get(pk=edit_id)
        return render(request, 'cbsadd-edit.html', {'obj': obj, 'msg': msg})

    def post(self, request, edit_id, test_id):
        msg = ''
        obj = models.presslist.objects.get(pk=edit_id)
        obj.name = request.POST.get('pressname')
        if models.presslist.objects.filter(name=obj.name):
            msg = '已存在'
        if not obj.name:
            msg = '不能为空'
        if not models.presslist.objects.filter(name=obj.name) and obj.name:
            obj.save()
            return redirect(reverse('presslist'))
        return self.get(request, edit_id, test_id, msg)