js download file on users computer code example

Example 1: javascript write to file and download

function download(filename, text) {
  var element = document.createElement('a');
  element.setAttribute('href', 'data:text/plain;charset=utf-8,' + encodeURIComponent(text));
  element.setAttribute('download', filename);

  element.style.display = 'none';
  document.body.appendChild(element);

  element.click();

  document.body.removeChild(element);
}

// Start file download.
download("hello.txt","This is the content of my file :)");

Example 2: typescript create file and download

var fileContents = "Hello world!";
var filename = "hello.txt";
var filetype = "text/plain";

var a = document.createElement("a");
dataURI = "data:" + filetype +
    ";base64," + btoa(fileContents);
a.href = dataURI;
a['download'] = filename;
var e = document.createEvent("MouseEvents");
// Use of deprecated function to satisfy TypeScript.
e.initMouseEvent("click", true, false,
    document.defaultView, 0, 0, 0, 0, 0,
    false, false, false, false, 0, null);
a.dispatchEvent(e);
a.removeNode();