The function is a bit like key listening, storing what someone types to a file on my computer. Can anyone help me?

CodePudding user response：

You don't have access to client machine files , but you can save them inside the browser database, it can be cookies , or local storages.

LocalStorage - JS

CodePudding user response：

If you are talking about browser javascript, you can not write data directly to local file for security reason. HTML 5 new API can only allow you to read files.

But if you want to write data, and enable user to download as a file to local. the following code works:

First we need to create a text file locally.

var textFile = null,
  makeTextFile = function (text) {
    var data = new Blob([text], {type: 'text/plain'});

    // If we are replacing a previously generated file we need to
    // manually revoke the object URL to avoid memory leaks.
    if (textFile !== null) {
      window.URL.revokeObjectURL(textFile);
    }

    textFile = window.URL.createObjectURL(data);

    // returns a URL you can use as a href
    return textFile;
  };

then we will write to that file.

 var create = document.getElementById('create'),
    textbox = document.getElementById('textbox');

  create.addEventListener('click', function () {
    var link = document.createElement('a');
    link.setAttribute('download', 'info.txt');
    link.href = makeTextFile(textbox.value);
    document.body.appendChild(link);

    // wait for the link to be added to the document
    window.requestAnimationFrame(function () {
      var event = new MouseEvent('click');
      link.dispatchEvent(event);
      document.body.removeChild(link);
    });

  }, false);