recursively zip a folder with php

recursive_zip.php

<?php

function Zip($source, $destination)
{
    if (extension_loaded('zip') === true)
    {
        if (file_exists($source) === true)
        {
                $zip = new ZipArchive();

                if ($zip->open($destination, ZIPARCHIVE::CREATE) === true)
                {
                        $source = realpath($source);

                        if (is_dir($source) === true)
                        {
                                $files = new RecursiveIteratorIterator(new RecursiveDirectoryIterator($source), RecursiveIteratorIterator::SELF_FIRST);

                                foreach ($files as $file)
                                {
                                        $file = realpath($file);

                                        if (is_dir($file) === true)
                                        {
                                                $zip->addEmptyDir(str_replace($source . '/', '', $file . '/'));
                                        }

                                        else if (is_file($file) === true)
                                        {
                                                $zip->addFromString(str_replace($source . '/', '', $file), file_get_contents($file));
                                        }
                                }
                        }

                        else if (is_file($source) === true)
                        {
                                $zip->addFromString(basename($source), file_get_contents($source));
                        }
                }

                return $zip->close();
        }
    }

    return false;
}

?>