How to have click event ONLY fire on parent DIV, not children?

If the e.target is the same element as this, you've not clicked on a descendant.

$('.foobar').on('click', function(e) {
  if (e.target !== this)
    return;
  
  alert( 'clicked the foobar' );
});
.foobar {
  padding: 20px; background: yellow;
}
span {
  background: blue; color: white; padding: 8px;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<div class='foobar'> .foobar (alert) 
  <span>child (no alert)</span>
</div>

There's another way that works if you don't mind only targeting newer browsers. Just add the CSS

pointer-events: none;

to any children of the div you want to capture the click. Here's the support tables

http://caniuse.com/#feat=pointer-events