如何在Django中创建装饰器来装饰视图

Question

我有看法:

@decorator
def func(request):
  hello = "hello"
  return render_to_responce("test.html", locals() )

和模板test.html:

{{ hello }}
{{ username }}

我想编写decorator for func(request),它为函数添加一个变量USERNAME,并在模板中返回两个参数.我试着按如下方式做到:

def decorator(func):
    def wrapper( request, *args, **kwargs):
        username = request.user.username
        q = func(request, *args, **kwargs)
        #what I need add here I do not know ...
        return q   
    return wrapper

Answer 1

如果您的视图如下所示:

def func(request, username):
    hello = "hello"
    return render_to_responce("test.html", locals() )

你可以这样写一个装饰器:

from functools import wraps
def pass_username(view):
    @wraps(view)
    def wrapper(request, *args, **kwargs):
        return view(request, request.user.username, *args, **kwargs)
    return wrapper

然后像这样使用它:

@pass_username
def func(request, username):
    hello = "hello"
    return render_to_response("test.html", locals())

(只是确保你会像对待它urls.py一样对待它- def func(request):没有username- 这个参数将由装饰者提供)

但实际上这是非常简单的情况,并不需要单独的装饰器(无论如何,它只是视图定义中的一个额外的行).