Make function wait until element exists

Question

I\'m trying to add a canvas over another canvas – how can I make this function wait to start until the first canvas is created?

function PaintObject(brush) {         


        

Answer 1

A more modern approach to waiting for elements:

while(!document.querySelector(".my-selector")) {
  await new Promise(r => setTimeout(r, 500));
}
// now the element is loaded

Note that this code would need to be wrapped in an async function.