Look at this code, which is some kind of "default value initializer" for a property.

This is used in my development of a framework including some getters that read linked data on the fly : the property value is read from the DAO only when someone want to read it.

The example above is a simplified version of what I do, with a static initialization.

class Classy
{
    public $prop;
}

function propInit(AopJoinpoint $joinpoint)
{
    $object = $joinpoint->getObject();
    $property = $joinpoint->getPropertyName();
    if (!isset($object->$property)) {
        $object->$property = array("my", "default", "values");
    }
}

$object = new Classy();
echo print_r($object->prop, true);

// Will display :
// array(0 => my, 1 => default, 2 => values)

But now I replace my echo by something more complicated. In some cases I need call-by-reference. Remove the echo and replace it with it :

function propDisplay(&$prop)
{
    echo print_r($prop, true);
}

$object = new Classy();
propDisplay($object->prop);

// Should display the same :
// array(0 => my, 1 => default, 2 => values)
// Will display :
// nothing !

In this case the advice is not called on propDisplay($object->prop) call, because the value of the property is not read by PHP, but it's reference is sent to the called function.

When inside the function, I do not access to a property but to a local variable, and the hook does not work. propInit() will never be called in this case.

My workaround :

$object->prop;
propDisplay($object->prop);

But I have to think about it each time I call a function that awaits references... not very transparent.

What answer should you provide ?

If possible, please make AOP joinpoints work when I call propDisplay($object->prop), even if the parameters are passed by reference. Could you do that ?