Download Zip files in yii

Download Zip Files Using Yii

Here i added the code to download the Zip files in yii folder.
SourceCode:

 public function downloadfinal($docid,$docname)
    {
        $filename=Dirdetails"filename.zip"; 
        if(file_exists($filename)){
            $path_parts = pathinfo($filename); 
            $ext = strtolower($path_parts["extension"]); 
            switch ($ext) 
            { 
              case "pdf": $ctype="application/pdf"; break; 
              case "exe": $ctype="application/octet-stream"; break; 
              case "zip": $ctype="application/zip"; break; 
              case "doc": $ctype="application/msword"; break; 
              case "xls": $ctype="application/vnd.ms-excel"; break; 
              case "ppt": $ctype="application/vnd.ms-powerpoint"; break; 
              case "gif": $ctype="image/gif"; break; 
              case "png": $ctype="image/png"; break; 
              case "jpg": $ctype="image/jpg"; break; 
              default: $ctype="application/force-download"; 
            } 
            $newpath=$extract.'/'.$filename;    
            header("Pragma: public");
            header("Content-Type: application/$ctype");
            header("Content-Disposition: inline; filename=$docname");
            header('Content-Length: '.filesize($filename));
            header("Accept Ranges: bytes");
            header("Expires: 0"); 
            header("Cache-Control: must-revalidate, post-check=0, pre-check=0"); 
            readfile("$filename");
        }
       else
       {
        echo "error";
       }
   }