Extending Class with self::

[Marcus]

When I extend a class with self:: and reusing something of its code at the beginning to check (calling the parent function later), from my understanding I should have to change self:: with $this, is that correct?

Or has self:: also access to the parent functions my class is extending?

 

[Chris D]

self:: refers to the current class.

$this refers to the current object.

 

[Marcus]

class Alerts_Model_Alert extends XFCP_Alerts_Model_Alert
{
public function markAllAlertsReadForUser($userId, $time = null)
  {
  if (self::PREVENT_MARK_READ)
  {
  return;
  }

So this code in my addon would also check against the extended classes constant PREVENT_MARK_THREAD, is that right?