PHP - Automatically call one one before another?

Question

Hi, In PHP, is there any way to make class method automatically call some other specified method before the current one? (I'm basically looking to simulate before_filter from Ruby on Rails.

For example, calling function b directly but getting the output 'hello you'.

function a() 
{
echo 'hello';
}

function b() 
{
echo 'you';
}

Any advice appreciated.

Thanks.

Answer 1

See http://stackoverflow.com/questions/1933050/check-if-function-has-been-called-yet/1933087#1933087

Also, why not have a look at the RoR sourcecode to see how it is implemented. Should be easy to port.

Answer 2

PHP does not support filters.However, you could just modefy your own function to ensure that a() is always run before b().

function a() 
{ 
echo 'hello';
}

function b() 
{
a();
echo 'you';
}

Answer 3

Not if you're not willing to override a b() to call both.

You might be interested in AOP for PHP though.

Answer 4

How about this:

function a() 
{
  echo 'hello';
}

function b() 
{
  a();
  echo 'you';
}

If you are under a class and both functions are in that class:

function a() 
{
  echo 'hello';
}

function b() 
{
  $this->a();
  echo 'you';
}

Not sure but possibly that's what you are looking for. thanks

Answer 5

Check this:

class Dispatcher {
    /*
     * somewhere in your framework you will determine the controller/action from path, right?
    */
    protected function getControllerAndActionFromPath($path) {
        /*
         * path parsing logic ...
        */
        if (class_exists($controllerClass)) {
            $controller = new $controllerClass(/*...*/);
            if (is_callable(array($controller, $actionMethod))) {
                $this->beforeFilter($controller);
                call_user_func(array($controller, $actionMethod));
                /*..
                 * $this->afterFilter($controller);
                 * ...*/
            }
        }
    }

    protected function beforeFilter($controller) {
        foreach ($controller->beforeFilter as $filter) {
            if (is_callable(array($controller, $filter))) {
                call_user_func(array($controller, $filter));
            }
        }
    }

    /*...*/
}

class FilterTestController extends Controller {
    protected $beforeFilter = array('a');

    function a() {
        echo 'hello';
    }

    function b() {
        echo 'you';
    }
}