The Shape Example in PHP 5

Contributed by Marcus Cavalcanti

I saw your article about OO examples in many languages and I would like to contribute in a new version of PHP implementation.

The current OO PHP implementation in your article does not include the new OO features in PHP 5 (or >) version, so I made an example with a new implementation based in the original problem.

My implementation has 5 files: the interface (Shape.php), the classes (Circle.php and Rectangle.php), the script to run/test the problem (main.php) and finally the results output (output.txt).

If you have problems with the files, please contact me.

Regards,

Marcus Cavalcanti
www.marcuscavalcanti.net

Code for PHP 5

File: Shape.php

<?php

interface Shape {
	public function Draw();
	public function MoveTo($x, $y);
	public function RMoveTo($dx, $dy);
}

?>

File: Rectangle.php

<?php

class Rectangle implements Shape {
	// If a method can be static, declare it static. Speed improvement is by a factor of 4. (http://vega.rd.no/article/php-static-method-performance)
	private static $width;
	private static $height;
	private static $x;
	private static $y;
	
	function __construct ($x, $y, $width, $height) {
		self::$x      = (float) $x;
		self::$y      = (float) $y;
		self::$width  = (float) $width;
		self::$height = (float) $height;
	}
	
	public function Draw () {
		echo sprintf("Drawing a Rectangle at %d, %d, width %d, height %d<br>", self::$x, self::$y, self::$width, self::$height);
	}
	
	public function MoveTo ($x, $y) {
		self::$x = $x;
		self::$y = $y;
	}
	
	public function RMoveTo ($dx, $dy) {
		self::$x += $dx;
		self::$y += $dy;
	}
	
	public static function __set ($var, $val) {		
       self::$$var = (float) $val; // note the '$$'
	}
	
    public static function __get ($var) {
        return  self::$$var; // note the '$$'
    }
}

?>

File: Circle.php

<?php

class Circle implements Shape {
	// if a method can be static, declare it static. Speed improvement is by a factor of 4. (http://vega.rd.no/article/php-static-method-performance)
	private static $radius;
	private static $x;
	private static $y;
	
	function __construct($x, $y, $radius) {
		self::$x      = (float) $x;
		self::$y      = (float) $y;
		self::$radius = (float) $radius;
	}
	
	public function Draw () {
		echo sprintf("Drawing a Circle at %d, %d, radius %d<br>", self::$x, self::$y, self::$radius);
	}
	
	public function MoveTo ($x, $y) {
		self::$x = $x;
		self::$y = $y;		
	}
	
	public function RMoveTo ($dx, $dy) {
		self::$x += $dx;
		self::$y += $dy;
	}	
	
	public static function __set ($var, $val) {		
       self::$$var = (float) $val; // note the '$$'
    }

    public static function __get ($var) {
        return  self::$$var; // note the '$$'
    }
}

?>

File: main.php

<?php
	
	// load the Circle and Rectangle classes and Shape interface
	function __autoload ($className) {    
		require $className . '.php';
	}
	
	// set up an array with some shape instances	 
    $shapes = array(new Rectangle(10, 20, 5, 6), new Circle(15, 25, 8));
    
    // iterate through the shapes
   	for ($i = 0; $i < 2; $i++) {
    	$shapes[$i]->Draw();
      	$shapes[$i]->RMoveTo(100, 100);
      	$shapes[$i]->Draw();
   	}
	
   	echo "<br><br>";
	
   	// circle specific functions
	$circle = new Circle(10, 20, 30);
	$circle->Draw();
	$circle->radius = 100; // set new value with __set "magic method"
	$circle->Draw();
	$circle->MoveTo(200, 200);
	$circle->Draw();
	
	echo "<br><br>";
	
	// rectangle specific functions
	$rectangle = new Rectangle(10, 20, 30, 40);
	$rectangle->Draw();
	$rectangle->width  = 100; // set new value with __set "magic method"
	$rectangle->height = 195; // set new value with __set "magic method"
	$rectangle->Draw();
	$rectangle->RMoveTo(10, 10);
	$rectangle->Draw();

?>

Output

Drawing a Rectangle at 10, 20, width 5, height 6
Drawing a Rectangle at 110, 120, width 5, height 6
Drawing a Circle at 15, 25, radius 8
Drawing a Circle at 115, 125, radius 8


Drawing a Circle at 10, 20, radius 30
Drawing a Circle at 10, 20, radius 100
Drawing a Circle at 200, 200, radius 100


Drawing a Rectangle at 10, 20, width 30, height 40
Drawing a Rectangle at 10, 20, width 100, height 195
Drawing a Rectangle at 20, 30, width 100, height 195