js_download.js

// from http://stackoverflow.com/a/29304414
var download = function(content, fileName, mimeType) {
  var a = document.createElement('a');

  if (navigator.msSaveBlob) { // IE10
    return navigator.msSaveBlob(new Blob([content], { type: mimeType }),     fileName);
  } else if ('download' in a) { //html5 A[download]
    a.href = 'data:' + mimeType + ',' + encodeURIComponent(content);
    a.setAttribute('download', fileName);
    document.body.appendChild(a);
    setTimeout(function() {
      a.click();
      document.body.removeChild(a);
    }, 100);
    return true;
  } else { //do iframe dataURL download (old ch+FF):
    var f = document.createElement('iframe');
    document.body.appendChild(f);
    f.src = 'data:' + mimeType + ',' + encodeURIComponent(content);

    setTimeout(function() {
      document.body.removeChild(f);
    }, 500);
    return true;
  }
};