PHP Class get by class

[KingIsulgard]

Is there a way in PHP to protect certain classes to only be created via another class?

 

So you can't access them directly, it should first pass another class before it gets created.

 

So CLASSA->do(); will return an instance of CLASSB

but CLASSB() shouldn't work to get an instance.

 

Is something like this possible? I want to create something like packages in java.

[Mchl]

Make CLASSB constructor private.

 

Also create a static method CLASSB::getInstance($CLASSAobject) that will return an instance if $CLASSAobject is implementing the correct interface.

(I don't like this solution, but can't think of anything bbetter right now)

[KingIsulgard]

I already made the static function and made the constructors protected, but that didn't work eather.

[MadTechie]

I'm probably missing thing here but

can't  you just make class B abstract

ie

<?php
abstract class ClassB{
function __construct(){}

function test(){
	return "Class B";
}
}

class ClassA extends ClassB{
function DoIT(){
	return $this;
}
}

$A = new ClassA();
$B = $A->DoIT();
echo $B->test();
// returns "Class B"

$X = new ClassB();
// return Fatal error:  Cannot instantiate abstract class ClassB

[Mchl]

How about this?

<?php
interface interfaceA {}

class CLASSA {

public function doSomething() {
	return CLASSB::returnInstance($this);
}

}

class CLASSAi implements interfaceA {

public function doSomething() {
	return CLASSB::returnInstance($this);
}

}

class CLASSB {

private function __construct() {}

public static function returnInstance($obj) {
	if($obj instanceof interfaceA) {
		return new CLASSB();
	} else {
		return false;
	}

}

}

$objA = new CLASSA();

var_dump($objA->doSomething()); //bool(false)

$objAi = new CLASSAi();

var_dump($objAi->doSomething());  //object(CLASSB)