Function that zip's a directory. Including all files and sub-directories. @param string dirname(name of target dir), @param object zip (object of ZipArchive)

zipFilesFunction.php

<?php
public function zipFiles($dirName, $zip) {
	$zipName = $dirName.'.zip';
	$filenames = array();
	$path = $this->_uploadFolder.$dirName.'/';
	ini_set('max_execution_time', 5000);

	// Opening and creating zip file
	if($zip->open($path.$zipName, $overwrite ? ZIPARCHIVE::OVERWRITE : 
			ZIPARCHIVE::CREATE) !== true) {
		return "Failed to open directory to zip!";
	}

	// initialize an iterator and tpass in the target directory
	$iterator = new RecursiveIteratorIterator(new RecursiveDirectoryIterator($path));

	// Iterates over a directory
	foreach ($iterator as $key => $value) {
		$zip->addFile(realpath($key), $key) or die ("ERROR: Could not add file $key");
	}

	// close and save the archive
	$zip->close();

	return $zipName;
}
?>