<!DOCTYPE html>
<html>
<head>
<title>Drag-and-drop test</title>
<style>
#drop {
width: 5em;
height: 5em;
border: 1px solid black;
}
</style>
</head>
<body>
<div id="drag" draggable="true">drag me</div>
<div id="drop"></div>
<div id="drag-state">0</div>
<script>
const drag = document.getElementById('drag');
const drop = document.getElementById('drop');
drag.addEventListener('dragstart', function(event) {
event.dataTransfer.setData('id', event.target.id);
document.getElementById('drag-state').textContent += '1';
});
drop.addEventListener('dragenter', function(event) {
event.preventDefault();
document.getElementById('drag-state').textContent += '2';
});
drop.addEventListener('dragover', function(event) {
event.preventDefault();
document.getElementById('drag-state').textContent += '3';
});
drop.addEventListener('drop', function(event) {
event.preventDefault();
const id = event.dataTransfer.getData('id');
const el = document.getElementById(id);
if (el) {
event.target.appendChild(el);
document.getElementById('drag-state').textContent += '4';
}
});
</script>
</body>
</html>