Unprovoked rewrite of Schwippy Tree script.

light_controller.php

<?php
// create the light controller and assign the color codes.
$lights = new LightController(
  //-- our color codes
  array(
    'blue'  => 'G5',
    'white' => 'G6',
    'green' => 'G7',
    'red'   => 'G8'
  )
);


// 'fluent' interface.  We can just string things together here.
// $lights->green('off')->green('on')->white('on')->red('off');
// 
// or, to make it a little more readable.
// $lights->green('off')
//        ->green('on')
//        ->white('on')
//        ->red('off');
//        
// BUT, we're going to do it as a simple API.

// another way to do this would be for urls like: 
// light_controller.php?red=on&blue=off
// doing it this way will allow us to specify several colors/states at once.
// could be used for an animation.
if (!empty($_GET)) {
  foreach ($_GET as $color => $state)
    $lights->{$color}($state);
}

// this will result in the API url being: light_controller.php?color=red&state=on
// if (isset($_GET['color']) && isset($_GET['state'])) {
//   $lights->{$_GET['color']}($_GET['state']);
// }

// here is the magic.
// "something about dragons below"
class LightController
{
    private $_colors   = array();
    private $_states  = array('on', 'off');

    public function __construct(array $colors=array())
    {
      $this->_colors = $colors;
    }

    public function __call($color, $arguments)
    {
      $state = $arguments[0];
      // check for a valid color and a valid state
      if (in_array($state, $this->_states) AND array_key_exists($color, $this->_colors))
        // do work
        $this->send($color, $state);
      
      return $this;
    }

    private function send($color, $state)
    {
      // compile the command string
      $command = sprintf('heyu %s %s', 
                         $state, 
                         $this->_colors[$color]
                 );

       passthru($command);
      
      // you could also echo something out here.  
      // It would be display (or returned in your ajax call)
      echo sprintf('The color %s has been turned %s (using "%s")', $color, $state, $command);
      return $this;
    }
}
?>