Make an online application to open txt file

Question

This is far fetched, but I know it can and has been done. Do you know how to make an online website/app to open a file? Basicly a website or an app that can read and output a HTML/TXT file. Preferably, I would like to use javascript or jquery, but any language that works on a website will be fine, too. There are online apps like Text for Chrome that do it. Do you know how? It would be great if you could help me out here. If you have any questions, feel free to ask.

Answer 1

Try utilizing <input> element ; <textarea> element ; accept="text/plain" attribute at input element ; onchange event attached to input element ; FileReader() within onchange event to output uploaded text file to <textarea> element

var input = document.getElementById("input");
var output = document.querySelector("[for=input]");
input.onchange = function(e) {
  var reader = new FileReader();
  reader.onload = function(evt) {
    output.textContent = evt.target.result;
  };
  reader.readAsText(e.target.files[0]);
};

<input id="input" type="file" accept="text/plain" /><br />
<textarea for="input" style="width:300px;height:300px;"></textarea>