如何在不编写每个视图中的逻辑的情况下呈现值，Django

发布于11月06日

在我看来，我想从数据库请求数据，在其他页面上，我也需要这些信息，但我不想再次编写这个请求逻辑.

Views.py

def account(request):
    user_id = request.user.id
    balance = Customer.objects.filter(name_id=user_id).values("usd").first()
    bonus = Customer.objects.filter(name_id=user_id).values("bonus").first()

    context1 = {'usd':balance['usd'],
                'bonus':bonus['bonus'],

    return render(request, 'account.html', context1)

def main(request):
    (here I also need to request balance and bonus)

In def main(request): and on other pages I also need balance and bonus, but I don't really want to request this values in every view.
Can I somehow write it somewhere once and to render on pages, and do not write it in every view??

推荐答案

首先，我不认为对balance和bonus执行两次相同的Customer模型的查询比查询Customer实例并访问其属性customer.balance/customer.bonus更高效.

尽管如此，有两个主要选项可以使该代码可重用:

Put it in the function个

def get_balance_and_bonus(request):
    customer = Customer.objects.filter(name_id=request.user.id).first()
    return customer.balance, customer.bonus

并在以下情况下使用它:

balance, bonus = get_balance_and_bonus(request)

第二种(更复杂的)方法是将所有需要客户的视图设置为make a decorator.

演绎客户的装饰师:

def add_customer(func):
    def wrap(*args, **kwargs):
        request = args[0]
        user_id = request.user.id
        kwargs['customer'] = Customer.objects.filter(name_id=user_id).first()
        return func(*args, **kwargs)
    return wrap

然后将其添加到需要Customer的所有函数中(请注意，在本例中，视图must中有相应的参数)

@add_customer
def account(request, customer):

    context1 = {'usd': customer.balance,
                'bonus': customer. bonus,

    return render(request, 'account.html', context1)

@add_customer
def main(request, customer):
    # here customer.balance and customer.bonus are available