Dynamically modified value of input not reflected in DOM

Question

How can I get the DOM to reflect the modified input value?

<div>
  <input value='0'>
</div>
<script src='http://ajax.googleapis.com/ajax/libs/jquery/1.5.0/jquery.min.js'></script>

<script>
setInterval(function() {
  $('input').val(parseInt($('input').val()) + 1)
  console.log('div.html(): ', $('div').html())
}, 1000)
</script>

Solution 1

The following seems to work for me:

http://jsfiddle.net/h8AP8/1/

All credit to gnarf here and his formhtml:

jQuery html() in Firefox (uses .innerHTML) ignores DOM changes

So your modified code would be:

<div>
  <input value='0'>
</div>
<script src='http://ajax.googleapis.com/ajax/libs/jquery/1.5.0/jquery.min.js'></script>

<script>
(function($) {
  var oldHTML = $.fn.html;

  $.fn.formhtml = function() {
    if (arguments.length) return oldHTML.apply(this,arguments);
    $("input,button", this).each(function() {
      this.setAttribute('value',this.value);
    });
    $("textarea", this).each(function() {
      // updated - thanks Raja!
      this.innerHTML = this.value;
    });
    $("input:radio,input:checkbox", this).each(function() {
      // im not really even sure you need to do this for "checked"
      // but what the heck, better safe than sorry
      if (this.checked) this.setAttribute('checked', 'checked');
      else this.removeAttribute('checked');
    });
    $("option", this).each(function() {
      // also not sure, but, better safe...
      if (this.selected) this.setAttribute('selected', 'selected');
      else this.removeAttribute('selected');
    });
    return oldHTML.apply(this);
  };

  //optional to override real .html() if you want
  // $.fn.html = $.fn.formhtml;
})(jQuery);


setInterval(function() {
  $('input').val(parseInt($('input').val()) + 1)
  console.log('div.html(): ', $('div').formhtml())
}, 1000)
</script>

Solution 2

Try changing the DOM directly. For example:

<div id="myDiv">
  <input id="myInput" value='0'>
</div>

<script>
setInterval(function() {
    var v = parseInt(document.getElementById("myInput").value) + 1;
    document.getElementById("myInput").setAttribute("value",v);
}, 1000);
</script>

<input type="button" onclick="javascript:alert(document.getElementById('myDiv').innerHTML);" value="Click to see DOM" />

Comments

[Jesse Aldridge]

+1 But I would still like to know why the jquery code didn't work.

[Jesse Aldridge]

Nope, this doesn't work either. The page runs fine, the problem is that the DOM never changes. Notice that value="0" never changes in the console log.

[Alejandro García Iglesias]

As the cited question suggests, it's a innerHTML problem. Actually, how different browsers implement innerHTML.

[MaXon]

This is an old post, and I was searching for the why as well. Here is what I found from another post, which explains the 'why' part. stackoverflow.com/questions/32793811/…