grails - Grails - cross controller code, execute on every request

Question

Is there a way of executing some piece of code before any controller action gets called?

I need to set a session variable based on the value of a get parameter, without taking into account which controller gets called.

Of course, once this processing is done, the request needs to follow its normal way to the corresponding controller/action.

Thanks

Answer 1

听起来您想使用过滤器。

例如grails-app/conf/MyFilter.groovy

class MyFilter {
    def filters = {
        extractSomething(controller: '*', action: '*') {
            before = {
                session.setAttribute('foo', params['paramName'])
            }
        }
    }
}

Answer 2

如果与多个或所有控制器一起使用，过滤器很好，但可能会变得昂贵。您也可以尝试拦截器：

def beforeInterceptor = {
       session.setAttribute('foo', params['paramName'])
}

http://www.grails.org/Controllers++-+拦截器