How to get the grid coordinates of an element using JavaScript?

Question

Let's say I have a 3-column CSS-Grid. Is there a way, using JavaScript, to get the grid-row and grid-column of an auto-placed element?

Example:

console.log($('#test').css('grid-row'), $('#test').css('grid-column'));
// expected output: 2 3 
// actual output: two empty strings

.grid {
  display: grid;
  grid-template-columns: repeat( 3, 1fr);
}

<div class="grid">
  <div></div>
  <div></div>
  <div></div>
  <div></div>
  <div></div>
  <div id="test"></div>
  <div></div>
  <div></div>
  <div></div>
</div>

Here is a JSFiddle of the example: https://jsfiddle.net/w4u87d2f/7/

In this example I could figure it out by counting the elements and knowing the grid has three columns:

grid-column = $('#test').index() % 3 + 1;
grid-row = Math.ceil( $('#test').index() / 3 )

But that only works for very simple grids and also means I have to consider breakpoints that change the number of columns.

Edit: This is not a duplicate of Retrieve the position (X,Y) of an HTML element, as I'm not interested in pixel coordinates but the row and column number within the CSS-Grid.

Answer 1

The above answer is a great start, and uses jQuery. Here is a pure Javascript equivalent, and also implements an "offset" in case you have specified the first child element's grid column (such as in a calendar where you specify the first day of the month)

function getGridElementsPosition(index) {
  const gridEl = document.getElementById("grid");

  // our indexes are zero-based but gridColumns are 1-based, so subtract 1
  let offset = Number(window.getComputedStyle(gridEl.children[0]).gridColumnStart) - 1; 

  // if we haven't specified the first child's grid column, then there is no offset
  if (isNaN(offset)) {
    offset = 0;
  }
  const colCount = window.getComputedStyle(gridEl).gridTemplateColumns.split(" ").length;

  const rowPosition = Math.floor((index + offset) / colCount);
  const colPosition = (index + offset) % colCount;

  //Return an object with properties row and column
  return { row: rowPosition, column: colPosition };
}

function getNodeIndex(elm) {
  var c = elm.parentNode.children,
    i = 0;
  for (; i < c.length; i++) if (c[i] == elm) return i;
}

function addClickEventsToGridItems() {
  let gridItems = document.getElementsByClassName("grid-item");
  for (let i = 0; i < gridItems.length; i++) {
    gridItems[i].onclick = (e) => {
      let position = getGridElementsPosition(getNodeIndex(e.target));
      console.log(`Node position is row ${position.row}, column ${position.column}`);
    };
  }
}

addClickEventsToGridItems();

Here is a corresponding Pen that shows it in action on a calendar with a specified offset.

Answer 2

//Add click event for any child div of div = grid
$(document).ready(function(){
    $('.grid').on('click', 'div', function(e){
          GetGridElementsPosition($(this).index()); //Pass in the index of the clicked div
    //Relevant to its siblings, in other words if this is the 5th div in the div = grid
    });
});

function GetGridElementsPosition(index){
    //Get the css attribute grid-template-columns from the css of class grid
    //split on whitespace and get the length, this will give you how many columns
    const colCount = $('.grid').css('grid-template-columns').split(' ').length;

    const rowPosition = Math.floor(index / colCount);
    const colPosition = index % colCount;

    //Return an object with properties row and column
    return { row: rowPosition, column: colPosition } ;
}