Format array using callback method

ArrayFormatter.php

<?php

/**
 * Formatter of Array
 * @author Jimmy Werder <jimmy.werder@gmail.com>
 * @version 0.1
 */
class ArrayFormatter
{

    const KEY = 1;
    const VALUE = 2;

    /**
     * @static
     * @access public
     * @param array $array Array
     * @param callable $funcName Static Method Callback Ex: "MyClass::myCallbackMethod"
     * @param mixed $funcParam [optional] Parameter of Method Callback. Default empty array
     * @param int $walkInto [optional] Choice to change array keys or values. Default Keys
     * @return array Formatted Array
     * @author Jimmy Werder <jimmy.werder@gmail.com>
     * @since 2015-04-28
     * @version 0.1
     * @throws Exception In case to param $change invalid.
     */
    public static function formatRecursive( array $array, callable $funcName, array $funcParam = array(), $walkInto = self::KEY )
    {
        $arrayFormatted = array();

        foreach ( $array as $k => $v ) {

            switch ( $walkInto ) {

                case self::KEY:

                    $funcParam[0] = $k;
                    $formattedKey = call_user_func_array( $funcName, $funcParam );

                    if ( is_array( $v ) )
                        $arrayFormatted[$formattedKey] = self::formatRecursive( $v, $funcName, $funcParam, $walkInto );
                    else
                        $arrayFormatted[$formattedKey] = $v;

                    break;

                case self::VALUE:

                    if ( is_array( $v ) ) {
                        $arrayFormatted[$k] = self::formatRecursive( $v, $funcName, $funcParam, $walkInto );
                    } else {
                        $funcParam[0] = $v;

                        $formattedValue = call_user_func_array( $funcName, $funcParam );
                        $arrayFormatted[$k] = $formattedValue;
                    }

                    break;

                default:
                    throw new \Exception( 'Invalid value in param "$walkTo" in ' . __CLASS__ );
            }
        }

        return $arrayFormatted;
    }

}