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PHP Factory Pattern Step By Step Tutorial - Part 1: In Object Oriented Programming, we always create new object with new operator. And in some cases, we need call same class for different steps. We can create a factory to avoid always call same class. The factory pattern encapsulates the creation of objects.

This is simple example that we always create new object every function that need it.

<?php
class Vehicle{

  function category($wheel = 0){
  	if($wheel == 2){
		return "Motor";
	}elseif($wheel == 4){
		return "Car";
	}
  }
}

class Spec{
	
  var $wheel = '';
	
  function Spec($wheel){
	$this->wheel = $wheel;	
  }
	
  function name(){
	$wheel = $this->wheel;
  	return Vehicle::category($wheel);
  }

  function brand(){
	$wheel = $this->wheel;  
  	$kind =& Vehicle::category($wheel);
	if($kind == "Motor"){
		return array('Harley','Honda');
	}elseif($kind = "Car"){
		return array('Nisan','Opel');	
	} 
  }
	
}

$kind = new Spec(2);
echo "Kind: ".$kind->name();
echo "<br>";
echo "Brand: ".implode(",",$kind->brand());
?>

This picture show how to implement factory pattern:

This is complete code after changing (implement factory pattern)

<?php
class Vehicle{

  function category($wheel = 0){
  	if($wheel == 2){
		return "Motor";
	}elseif($wheel == 4){
		return "Car";
	}
  }
}

class Spec{
	
  var $wheel = '';
  var $vc    = '';
  	
  function Spec($wheel){
	$this->wheel = $wheel;
	$this->_getVehicle();
  }
  
  function &_getVehicle(){
	$wheel = $this->wheel;
  	$this->vc =& Vehicle::category($wheel);
  }
	
  function name(){
  	return $this->vc;
  }

  function brand(){
	if($this->vc == "Motor"){
		return array('Harley','Honda');
	}elseif($this->vc = "Car"){
		return array('Nisan','Opel');	
	} 
  }
	
}

$kind = new Spec(2);
echo "Kind: ".$kind->name();
echo "<br>";
echo "Brand: ".implode(",",$kind->brand());
?>