Hello,

The example that follows this little description should, as far as my understanding of PHP goes, demonstrate proper passing of multilayered objects, by reference, to independent sub-objects.  The more understandable description, there exists a super-class that has two sub-classes.  The first sub-class, upon construction, is linked to the second sub-class (via a parameter passed to the first class' constructor).  The first sub-class' constructor sets a variable, local to that first sub-class, to be a reference to the second sub-class.  The second sub-class is comprised only of a variable that will be changed by functionality defined in the first sub-class.

The first code snippet does not function properly.  It seems that the first sub-class does not truly create a reference, but creates a copy of the second sub-class (as it exists upon construction of the first sub-class).  Therefore, it can not be changed, only read.

The second code snippet functions properly and implements what I label a hack around.  This code snippet accesses the second sub-class within the constructor of the first sub-class.  In other words, it seems that PHP does not create a reference, unless something within that reference is accessed within the function defining the reference.  <<Confusing, ain't it.>>

Please tell me if there is a more "correct" solution, or if I'm simply confused to oblivion. =)

--- [FIRST CODE SNIPPET] ---

<?
	class Test0_t
	{
		var $oTest1;
		var $oTest2;

		function Test0_t ()
		{
			$this->oTest1 = new Test1_t($this);
			$this->oTest2 = new Test2_t();
		}
	}

	class Test1_t
	{
		var $oLnk;

		function Test1_t ( &$_oLnk )
		{
			$this->oLnk = &$_oLnk;
		}

		function Test ()
		{
			echo("0:[".$this->oLnk->oTest2->nVal."]<BR>");
			$this->oLnk->oTest2->nVal++;
			echo("1:[".$this->oLnk->oTest2->nVal."]<BR>");
		}
	}

	class Test2_t {
		var $nVal;

		function Test2_t ()
		{
			$this->nVal = 0;
		}
	}

	$oTest0 = new Test0_t();

	$oTest0->oTest1->Test();

	echo("2:[".$oTest0->oTest2->nVal."]<BR>");
?>

--- [SECOND CODE SNIPPET] ---

<?
	class Test0_t
	{
		var $oTest1;
		var $oTest2;

		function Test0_t ()
		{
			$this->oTest2 = new Test2_t();
			$this->oTest1 = new Test1_t($this);
		}
	}

	class Test1_t
	{
		var $oLnk;

		function Test1_t ( &$_oLnk )
		{
			$this->oLnk = &$_oLnk;
			$this->oLnk->oTest2->Test();
		}

		function Test ()
		{
			echo("0:[".$this->oLnk->oTest2->nVal."]<BR>");
			$this->oLnk->oTest2->nVal++;
			echo("1:[".$this->oLnk->oTest2->nVal."]<BR>");
		}
	}

	class Test2_t {
		var $nVal;

		function Test2_t ()
		{
			$this->nVal = 0;
		}

		function Test ()
		{
		}
	}

	$oTest0 = new Test0_t();

	$oTest0->oTest1->Test();

	echo("2:[".$oTest0->oTest2->nVal."]<BR>");
?>

Thank you,
-Andrew Immerman