Design pattern examples using PHP. These are a bit dated, but hey. It's a gist.

php-design-patterns.php

<h1>Design Patterns</h1>

<h2>Singleton classes ( persist one object over multiple calls )</h2>

<?php



class Database
{

	private $connection = null ;

	public static function getDB()
	{
		static $database = null;
		if ( $database == null ) 
		{
			$database = new Database();
		}
		return $database;
	}

	private function __construct()
	{
		$this->connection = "Hurray, a database connection!" ;
	}

	public function databaseConnection()
	{
		return $this->connection;
	}
}

echo Database::getDB()->databaseConnection() ;

?>

<h2>Creating a factory ( seperating the logic gruntwork from the "creating"</h2>

<?php

 

interface BirthdaySong {
	function createSong();
}

class Song implements BirthdaySong {

	private $name ;

	public function __construct( $name_parameter ) 
	{
		$this->name = $name_parameter ;
	}

	public function createSong() 
	{
		$song = 'Happy birthday to you! <br/>' ;
		$song .= 'Happy birthday to you! <br/>' ;
		$song .= 'Happy birthday dear ' . $this->name ;
		$song .= '! <br/>' ;
		$song .= 'Happy birthday to you! <br/>' ;
		return $song;	
	}
	
}

class SongFactory {

	public static function Create( $name ) 
	{
		return new Song( $name );
	}
	
}

$userSong = SongFactory::Create( "Tony" );
echo $userSong->createSong() ;

?>

<h2>States ( very simple example of altering object states based on calls, and call order )</h2>

<?php 

class FluxCapacitor {

	private $state;

	public function timeJump()
	{
		if ( $this->state == "ready" )
		{
			echo("Jumping to 1985<br/>");
			
		} else if ( $this->state == "nopower" ) {
			echo("Needs more Plutonium<br/>");
		}
	}

	public function __construct() 
	{
		$this->state = "nopower";
	}

	public function nuke()
	{
		if ( $this->state == "ready" )
		{
			echo("Already has Plutonium");
		} else {
			$this->state = "ready" ;
			echo("Added Plutonium<br/>");
		}
	}

}

$delorean = new FluxCapacitor();
$delorean->timeJump();
$delorean->nuke();
$delorean->timeJump();




?>