download file using $fh.file

downloadfile.js

var fileSrc = "http://example.com/test.pdf";
var parts = fileSrc.split("/");
var destFile = parts[parts.length - 1];
var progressListener = function(progress){
  //progress value that is passed here is a float number between 0 and 1
  //convert it to percentage
  $('#download_progress').html('<p> current progress: ' + progress*100 + '%' + '</p>');
} 
$fh.file(
  {act:'download', src: fileSrc, dest: destFile, progressListener:progressListener}, 
  function(path){
    //open the downloaded file using $fh.webview
    //$fh.webview can open most of the file formats on ios (pdf, doc, xls etc)
    $fh.webview({act:'open', url: path});
  }, 
  function(err){
    alert(err);
  }
);