Finding element's position relative to the document

What's the easiest way to determine an elements position relative to the document/body/browser window?

Right now I'm using .offsetLeft/offsetTop, but this method only gives you the position relative to the parent element, so you need to determine how many parents to the body element, to know the position relaltive to the body/browser window/document position.

This method is also to cumbersome.

Solution 1:

You can get top and left without traversing DOM like this:

function getCoords(elem) { // crossbrowser version
    var box = elem.getBoundingClientRect();

    var body = document.body;
    var docEl = document.documentElement;

    var scrollTop = window.pageYOffset || docEl.scrollTop || body.scrollTop;
    var scrollLeft = window.pageXOffset || docEl.scrollLeft || body.scrollLeft;

    var clientTop = docEl.clientTop || body.clientTop || 0;
    var clientLeft = docEl.clientLeft || body.clientLeft || 0;

    var top  = box.top +  scrollTop - clientTop;
    var left = box.left + scrollLeft - clientLeft;

    return { top: Math.round(top), left: Math.round(left) };
}

Solution 2:

You can use element.getBoundingClientRect() to retrieve element position relative to the viewport.

Then use document.documentElement.scrollTop to calculate the viewport offset.

The sum of the two will give the element position relative to the document:

element.getBoundingClientRect().top + document.documentElement.scrollTop

Solution 3:

You can traverse the offsetParent up to the top level of the DOM.

function getOffsetLeft( elem )
{
    var offsetLeft = 0;
    do {
      if ( !isNaN( elem.offsetLeft ) )
      {
          offsetLeft += elem.offsetLeft;
      }
    } while( elem = elem.offsetParent );
    return offsetLeft;
}

Solution 4:

I've found the following method to be the most reliable when dealing with edge cases that trip up offsetTop/offsetLeft.

function getPosition(element) {
    var clientRect = element.getBoundingClientRect();
    return {left: clientRect.left + document.body.scrollLeft,
            top: clientRect.top + document.body.scrollTop};
}