php snippet to easily get a list of constant key/values from a class. easy in a util class for reuse.

gistfile1.php

    /**
     * gets the constants from a class. this is useful if the constants are part
     * of a logical group (especially when prefixed with the same value)
     * @param string $from the classname (can be __CLASS__)
     * @param string $prefix the prefix for the constants
     * @param string $values_only do we want a key=>value array or values only
     * @return array
     */
    public static function getConstants($from, $prefix = null, $values_only = false) 
    {
        $reflection = new ReflectionClass($from);
        $constants = $reflection->getConstants();
        
        //filter constants on prefix if necessary
        if($prefix !== null) {
            $filtered = array();
            foreach($constants as $key => $value)
            {
                if( substr($key,0 ,strlen($prefix)) === $prefix){
                    $filtered[$key] = $value;
                }
            }
            //swap
            $constants = $filtered;
        }
        
        if($values_only) {
            $constants =  array_values($constants);
        }
        
        return $constants;
    }