jQuery get position of element relative to another element

Question

So I have a div like:

And I want to know the position

Answer 1

The problem for me was the fact that I was in a div with a scrollbar and that I had to be able to take into account the hidden part down to the root element.

If I use ".offset()" it gave me wrong values, because it does not take into consideration the hide part of scrollbar as it is relative to the document.

However, I realized that the ".offsetTop" property relative to its first parent positioned (offsetParent) was always correct. So I made a loop to go recursively to the root element by additionning the values of ".offsetTop":

I did my own jquery function for that:

jQuery.fn.getOffsetTopFromRootParent = function () {
    let elem = this[0];
    let offset = 0;
    while (elem.offsetParent != null) {
        offset += elem.offsetTop;
        elem = $(elem.offsetParent)[0];
        if (elem.offsetParent === null) {
            offset += elem.offsetTop;
        }
    }
    return offset;
};

You can use the same with ".offsetLeft" I suppose...

If you want to get position of element relative to another element to answer the question:

let fromElem = $("#fromElemID")[0];
let offset = 0;
while (fromElem.id.toUpperCase() != "toElemID".toUpperCase()) {
    offset += fromElem.offsetTop;
    fromElem = $(fromElem.offsetParent)[0];
}
return offset;

An element (offsetParent) is said to be positioned if it has a CSS position attribute of relative, absolute, or fixed.