Create Zip File for Multiple files to be downloadable in Codeigniter

define('ROOT_DOWNLOAD_FOLDER_PATH', $_SERVER['DOCUMENT_ROOT']."_files/_downloads/");

function CreateZipFile($zip_folder_name)
{
 $directoryToZip = ROOT_DOWNLOAD_FOLDER_PATH; // This will zip all the file(s) in this present working directory
 $outputDir = ROOT_DOWNLOAD_FOLDER_PATH; //Replace "/" with the name of the desired output directory.
 $this->load->library('ZipFile');
  
 //$this->createzipfile->get_files_from_folder($outputDir, $zip_folder_name.'-');
 $this->zipfile->get_files_from_folder($directoryToZip, '');
 
 //Code toZip a directory and all its files/subdirectories
 $this->zipfile->zipDirectory($directoryToZip, $outputDir);
 
 $fileName = $outputDir.$zip_folder_name.'.zip';

 $fd = fopen ($fileName, 'wb');
 $out = fwrite ($fd, $this->zipfile->getZippedfile());
  
 $this->zipfile->forceDownload($fileName);
 
 @unlink($fileName);
 fclose($fd);
 
 /* Empty directory and remove directory. */
 $directoryToZipPath = $directoryToZip.$zip_folder_name;
 unlinkFolderFiles($directoryToZipPath);
 removeDir($directoryToZipPath);

 exit;
}

$timestamp = date('Y.m.d.h.i.s');
$timestamp = '2012.08.15.12.45.46';
$zip_folder_name = 'Flubit.Inv.All.'.$timestamp;

// For the ZipFile.php, save the below ZipFile.php file content into application/libaries/ZipFile.php

/**
 * Class to dynamically create a zip file (archive) of file(s) and/or directory
 *
 * @author Rochak Chauhan  www.rochakchauhan.com
 * @package CreateZipFile
 * @see Distributed under "General Public License"
 * 
 * @version 1.0
 */

class ZipFile {

 public $compressedData = array();
 public $centralDirectory = array(); // central directory
 public $endOfCentralDirectory = "\x50\x4b\x05\x06\x00\x00\x00\x00"; //end of Central directory record
 public $oldOffset = 0;
 
 function get_files_from_folder($directory, $put_into) {
  if ($handle = opendir($directory)) {
   while (false !== ($file = readdir($handle))) {
    if (is_file($directory.$file)) {
     $fileContents = file_get_contents($directory.$file);
     $this->addFile($fileContents, $put_into.$file);
    } elseif ($file != '.' and $file != '..' and is_dir($directory.$file)) {
     $this->addDirectory($put_into.$file.'/');
     $this->get_files_from_folder($directory.$file.'/', $put_into.$file.'/');
    }
   }
  }
  closedir($handle);
 }
 
 /**
  * Function to create the directory where the file(s) will be unzipped
  *
  * @param string $directoryName
  * @access public
  * @return void
  */ 
 public function addDirectory($directoryName) {
  $directoryName = str_replace("\\", "/", $directoryName);
  $feedArrayRow = "\x50\x4b\x03\x04";
  $feedArrayRow .= "\x0a\x00";
  $feedArrayRow .= "\x00\x00";
  $feedArrayRow .= "\x00\x00";
  $feedArrayRow .= "\x00\x00\x00\x00";
  $feedArrayRow .= pack("V",0);
  $feedArrayRow .= pack("V",0);
  $feedArrayRow .= pack("V",0);
  $feedArrayRow .= pack("v", strlen($directoryName) );
  $feedArrayRow .= pack("v", 0 );
  $feedArrayRow .= $directoryName;
  $feedArrayRow .= pack("V",0);
  $feedArrayRow .= pack("V",0);
  $feedArrayRow .= pack("V",0);
  $this->compressedData[] = $feedArrayRow;
  $newOffset = strlen(implode("", $this->compressedData));
  $addCentralRecord = "\x50\x4b\x01\x02";
  $addCentralRecord .="\x00\x00";
  $addCentralRecord .="\x0a\x00";
  $addCentralRecord .="\x00\x00";
  $addCentralRecord .="\x00\x00";
  $addCentralRecord .="\x00\x00\x00\x00";
  $addCentralRecord .= pack("V",0);
  $addCentralRecord .= pack("V",0);
  $addCentralRecord .= pack("V",0);
  $addCentralRecord .= pack("v", strlen($directoryName) );
  $addCentralRecord .= pack("v", 0 );
  $addCentralRecord .= pack("v", 0 );
  $addCentralRecord .= pack("v", 0 );
  $addCentralRecord .= pack("v", 0 );
  $addCentralRecord .= pack("V", 16 );
  $addCentralRecord .= pack("V", $this->oldOffset );
  $this->oldOffset = $newOffset;
  $addCentralRecord .= $directoryName;
  $this->centralDirectory[] = $addCentralRecord;
 }

 /**
  * Function to add file(s) to the specified directory in the archive 
  *
  * @param string $directoryName
  * @param string $data
  * @return void
  * @access public
  */ 
 public function addFile($data, $directoryName)   {
  $directoryName = str_replace("\\", "/", $directoryName);
  $feedArrayRow = "\x50\x4b\x03\x04";
  $feedArrayRow .= "\x14\x00";
  $feedArrayRow .= "\x00\x00";
  $feedArrayRow .= "\x08\x00";
  $feedArrayRow .= "\x00\x00\x00\x00";
  $uncompressedLength = strlen($data);
  $compression = crc32($data);
  $gzCompressedData = gzcompress($data);
  $gzCompressedData = substr( substr($gzCompressedData, 0, strlen($gzCompressedData) - 4), 2);
  $compressedLength = strlen($gzCompressedData);
  $feedArrayRow .= pack("V",$compression);
  $feedArrayRow .= pack("V",$compressedLength);
  $feedArrayRow .= pack("V",$uncompressedLength);
  $feedArrayRow .= pack("v", strlen($directoryName) );
  $feedArrayRow .= pack("v", 0 );
  $feedArrayRow .= $directoryName;
  $feedArrayRow .= $gzCompressedData;
  $feedArrayRow .= pack("V",$compression);
  $feedArrayRow .= pack("V",$compressedLength);
  $feedArrayRow .= pack("V",$uncompressedLength);
  $this->compressedData[] = $feedArrayRow;
  $newOffset = strlen(implode("", $this->compressedData));
  $addCentralRecord = "\x50\x4b\x01\x02";
  $addCentralRecord .="\x00\x00";
  $addCentralRecord .="\x14\x00";
  $addCentralRecord .="\x00\x00";
  $addCentralRecord .="\x08\x00";
  $addCentralRecord .="\x00\x00\x00\x00";
  $addCentralRecord .= pack("V",$compression);
  $addCentralRecord .= pack("V",$compressedLength);
  $addCentralRecord .= pack("V",$uncompressedLength);
  $addCentralRecord .= pack("v", strlen($directoryName) );
  $addCentralRecord .= pack("v", 0 );
  $addCentralRecord .= pack("v", 0 );
  $addCentralRecord .= pack("v", 0 );
  $addCentralRecord .= pack("v", 0 );
  $addCentralRecord .= pack("V", 32 );
  $addCentralRecord .= pack("V", $this->oldOffset );
  $this->oldOffset = $newOffset;
  $addCentralRecord .= $directoryName;
  $this->centralDirectory[] = $addCentralRecord;
 }

 /**
  * Function to return the zip file
  *
  * @return zipfile (archive)
  * @access public
  * @return void
  */
 public function getZippedfile() {
  $data = implode("", $this->compressedData);
  $controlDirectory = implode("", $this->centralDirectory);
  return
  $data.
  $controlDirectory.
  $this->endOfCentralDirectory.
  pack("v", sizeof($this->centralDirectory)).
  pack("v", sizeof($this->centralDirectory)).
  pack("V", strlen($controlDirectory)).
  pack("V", strlen($data)).
  "\x00\x00";
 }

 /**
  *
  * Function to force the download of the archive as soon as it is created
  *
  * @param archiveName string - name of the created archive file
  * @access public
  * @return ZipFile via Header
  */
 public function forceDownload($archiveName) {
  if(ini_get('zlib.output_compression')) {
   ini_set('zlib.output_compression', 'Off');
  }

  // Security checks
  if( $archiveName == "" ) {
   echo "
ERROR: The download file was NOT SPECIFIED.";
   exit;
  }
  elseif ( ! file_exists( $archiveName ) ) {
   echo "
ERROR: File not found.";
   exit;
  }

  header("Pragma: public");
  header("Expires: 0");
  header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
  header("Cache-Control: private",false);
  header("Content-Type: application/zip");
  header("Content-Disposition: attachment; filename=".basename($archiveName).";" );
  header("Content-Transfer-Encoding: binary");
  header("Content-Length: ".filesize($archiveName));
  readfile("$archiveName");
 }

 /**
   * Function to parse a directory to return all its files and sub directories as array
   *
   * @param string $dir
   * @access protected 
   * @return array
   */
 protected function parseDirectory($rootPath, $seperator="/"){
  $fileArray=array();
  $handle = opendir($rootPath);
  while( ($file = @readdir($handle))!==false) {
   if($file !='.' && $file !='..'){
    if (is_dir($rootPath.$seperator.$file)){
     $array=$this->parseDirectory($rootPath.$seperator.$file);
     $fileArray=array_merge($array,$fileArray);
    }
    else {
     $fileArray[]=$rootPath.$seperator.$file;
    }
   }
  }  
  return $fileArray;
 }

 /**
  * Function to Zip entire directory with all its files and subdirectories 
  *
  * @param string $dirName
  * @access public
  * @return void
  */
 public function zipDirectory($dirName, $outputDir) {
  if (!is_dir($dirName)){
   trigger_error("CreateZipFile FATAL ERROR: Could not locate the specified directory $dirName", E_USER_ERROR);
  }
  $tmp=$this->parseDirectory($dirName);
  $count=count($tmp);
  $this->addDirectory($outputDir);
  for ($i=0;$i<$count;$i++){
   $fileToZip=trim($tmp[$i]);
   $newOutputDir=substr($fileToZip,0,(strrpos($fileToZip,'/')+1));
   $outputDir=$outputDir.$newOutputDir;
   $fileContents=file_get_contents($fileToZip);
   $this->addFile($fileContents,$fileToZip);
  }
 }
}

// The below are the basic File and Directory Related functions.

function createFile($filePath='')
{
 try {
  if (!empty($filePath))
  { 
   $ourFileHandle = fopen($filePath, 'w');
   fclose($ourFileHandle);
  }
  return true;
 }
 Catch(Exception $e){ return false; }
}

function unlinkFolderFiles($dir)
{
 $files = getFolderFiles($dir);

 foreach ($files as $file)
 {
  if(file_exists($dir.'/'.$file)) @unlink($dir.'/'.$file);
 }

 return true;
}

function getFolderFiles($dir)
{
 $files = '';
 $ffs = scandir($dir);

 foreach($ffs as $ff)
 {
  if($ff != '.' && $ff != '..')
  {
   $files[] = $ff;
  }
 }

 return $files;
}

function createDir($dir)
{
 if (!is_dir($dir)) {
  mkdir($dir);
 }

 return true;
}

function removeDir($dir)
{
 if (is_dir($dir)) {
  rmdir($dir);
 }
 
 return true;
}

Convert the date time to timestamp and Compare the two datetime (dates) functions in Javascript.

Convert the date time to timestamp in Javascript. similar to strototime() function in php.

// Convert the date time to timestamp in Javascript. similar to strototime() function in php.
function convert_datetime_to_timestamp(date)
{
 var datetime = date.split(" ");
 date = datetime[0];
 time = datetime[1];

 d1 = date.split("-");
 y = d1[0];
 m = d1[1];
 d = d1[2];

 t1 = time.split(":");
 h = t1[0];
 i = t1[1];
 s = t1[2];

 //datetime = m + ' ' + d + ',' + y + ' ' + h + ':' + i + ':'+s;
var date = new Date(y, m, d, h, i, s, '0'); (works both on FireFox and Chrome Browers).
 
 return date.getTime();
}

// Compare the two datetime (dates) in Javascript.

/*  This below function compares two dates with a gap time as 6 Hours.
 @param date1 = '2012-08-06 14:9:19'
 @param date2 = '2012-08-06 20:9:19' 
 @return If errors found, return errors else null (if no errors) found. 
*/
function compare_two_dates(date1, date2)
{
 var error = '';
 
 if ( (date1 != "") || (date2 != "") )
 {
  // Check the dates time here;
  var minutes=1000*60;
  var hours=minutes*60;
  var days=hours*24;
  var years=days*365;
  
  now = new Date();
  current_time= now.getTime();
  
  // Check the dates time here;
  start_time= convert_datetime_to_timestamp(date1);
  expiry_time= convert_datetime_to_timestamp(date2);
  
  gap_hr = 6; // Minimum Gap between two dates is set as 6 Hrs. 
  gap_time= gap_hr*hours;
  diff_time= expiry_time - start_time;
  diff_mm= (diff_time)/minutes;
  diff_hr= Math.round(diff_time/hours);
  
  if ( (current_time >= start_time) && (current_time >= expiry_time))
   error = 'Date Available AND/OR Expiry time should be greater than current time.';

  else if ( (diff_time == 0) || (gap_time > diff_time) )
   error = 'Date Expires should be at least ' + gap_hr + ' hours greater than Date Available time.';
  
  //error = error + ' NowT: '+current_time+' DS: ' + start_time + ' DE: '+ expiry_time+' Diff: ' +diff_time+ ' DMM: ' + diff_mm+ ' DHR: '+diff_hr+' TG: '+gap_time;  
 }
 else {
  error =  'Enter both dates';
 }
 
 return error;
}

For more information about dates, please, check: JavaScript Date Object, JavaScript setDate() Method