WordPress - class to extract your post meta in the form of an object; more elegant, easier to cache

class.viewoptions.php

/**
 * wp_view_options - extracts post meta as object members
 * @author Adrian S. (http://www.gridwave.co.uk/)
 * @version 1.0
 * 
 * Basic usage example: 
 *
 * $view_options = new wp_view_options( get_the_ID() );
 * ...
 * if( $view_options->background_color ) 
 *     echo ('#' . $view_options->background_color );
 *
 * Advanced usage example: 
 * 
 * $convert      =  array('yes'=>true, 'no'=>false); 
 * $view_options = new wp_view_options( get_the_ID(), $convert);
 * ...
 * if( $view_options->is_featured ) //in DB, is_featured may be yes or no, however because we have convert on, the value will be converted accordingly;
 *    echo 'post-featured';
 */

class wp_view_options{

    private $store    = array();
    private $multi    = array();

    private $conversions = array();

    private $post_id = 0;

    public function __construct($post_id=0, $multi=array(), $conversions=array()){
        global $post; if( empty($post_id) ) $post_id = $post->ID; $this->post_id = $post_id;  $this->multi = $multi; $this->conversions = array_change_key_case($conversions, CASE_LOWER);
    }

    public function convert($value){
        $unit = strtolower($value); return strlen($value) ? ( isset($this->conversions[$unit]) ? $this->conversions[$unit] : $value ) : null;
    }

    public function __get($name){

        if( $name == 'post_id' )
            return $this->post_id;

        if(  isset($this->store[$name]) ) return $this->store[$name];

        $value = get_post_meta($this->post_id, $name, in_array($name, $this->multi, true) ? false : true);
        $value = $this->convert($value);

        $this->{$name} = $value;

        return $value;
    }

    public function __set($name, $value){

        if( $name == 'post_id' )
            _doing_it_wrong(__CLASS__ . '->__set()', 'Post ID cannot be reset this way. Please create another instance of the class', '1.0');

        $this->store[$name] = $value;

    }

}