Prevent page unloaded while filling out a form

Demo

• Demo page

Examples

<script type="importmap">
  {
    "imports": {
      "@w0s/form-before-unload-confirm": "..."
    }
  }
</script>
<script type="module">
  import formBeforeUnloadConfirm from '@w0s/form-before-unload-confirm';

  formBeforeUnloadConfirm(document.querySelectorAll('.js-form-beforeunload-confirm')); // `getElementById()` or `getElementsByClassName()` or `getElementsByTagName()` or `querySelector()` or `querySelectorAll()`
</script>

<form class="js-form-beforeunload-confirm">
  <p><input /></p>
  <p><button>Submit</button></p>
</form>