Difference between offsetParent and parentElement or parentNode

Yuriy Galanter picture Yuriy Galanter · Jul 31, 2013 · Viewed 17.9k times · Source

I have a following DOM structure

<body>
    <div>
       <table>
          <outerElement>
              <innerElement />  
          </outerElement>
       <table>
    </div>
</body>

DIV has its overflow set to auto so if table grows bigger - it scrolls within the DIV.

In this scenario why table.offsetParent returns the body while both table.parentNode and parentElement return the Div?

I need to calculate current position of the innerElement within the window, so I traverse from it up thru all parent elements, collecting their offsetTop and offsetLeft values. Up until the DIV offsetParent works fine and then it skips it directly to the body. The problem if there's scrolling involved at some point, I need to account for scrollTop and scrollLeft as well - like in the DIV in the above example. The problem is if I use offsetParent I never encounter the DIV as one of the parents.

UPDATE

This is part of the code that does the traversing:

while (oElem && getStyle(oElem, 'position') != 'absolute' && getStyle(oElem, 'position') != 'relative') { 
   curleft += oElem.offsetLeft;
   curtop += oElem.offsetTop;
   oElem = oElem.offsetParent;
}

where getStyle is a custom function that in this case retrieves the position style.

Answer

kalley picture kalley · Jul 31, 2013

offsetParent is the closest parent that has position:relative or position:absolute or the body of the page. parentNode is the direct parent, regardless of position.