Is there an event that triggers when a cell is edited, but the value doesn't change?
<p>I am working on a sales tracker for our store. We log our sales with the sales tracker and I've got a method that I adapted from a question's answer here at Stack Overflow (Unfortunately I don't have a link or user I can attribute it to at the moment!) for editing a cell without having to mentally add amounts shown below.</p>

<pre><code> function onEdit(e) {


  var editRange = { // C5:O13
    top : 5,
    bottom : 13,
    left : 12,
    right : 12
  };

  //Checks if last value was not a number to avoid loop
  if (isNaN(e.value) == true) {
    return;
  }

  if (isNaN(e.oldValue) == true) {
    var newValue = parseInt(e.value);
  } else {
    var newValue = parseInt(e.value) + parseInt(e.oldValue);
  }

  // Exit if we're out of range
  var thisRow = e.range.getRow();
  if (thisRow &lt; editRange.top || thisRow &gt; editRange.bottom) return;

  var thisCol = e.range.getColumn();
  if (thisCol &lt; editRange.left || thisCol &gt; editRange.right) return;

  var posRow = parseInt(thisRow);
  var posCol = parseInt(thisCol);

  // We're in range
  var ss = e.range.getSheet();
  ss.getRange(posRow, posCol).setValue(newValue);

} ​
</code></pre>

<p>This allows the person that sells a device (e.g. worth $645) to add to their current amount (e.g. $450) by typing the current sales over the cell. The code takes the old amount, adds it to the new amount, and saves it back into the cell. </p>

<p>The problem arises when the current sale value is the same as the new sale value (e.g. $500 currently sold, and we just sold $500 again). The values haven't changed because the same value gets typed into the cell, and the onEdit() and onChange() functions do not fire. Is there any workaround for this?</p>