LocalStorage and event delegation are concepts I am familiar with. However, I am very excited doing this challenge!

Have you ever imagined adding event listener to element that never exist or will only exist in the future? That’s impossible, right? However, our assumption sometime tells otherwise.

Let’s say we want to delete item from to-do list (which is dynamically created and destroyed) whenever we click ✖ button on it. If we attach event listener to ✖ button, you won’t get anything works correctly if the item was newly created because you cannot attach event listener to nonexistence DOM element. Perhaps, it functions correctly for existing elements because it’s already on the page, but we’ve been wrong conceptually. That’s why we need event delegation to fix that problem.

Event delegation is not that fancy! It’s like attaching event listener to parent element (as for ul, there must be a bunch of li inside it), so child elements can function specifically without having to attach any event listeners to them.

Pay attention to this snippet:

  <ul id="parent">
      <a href='#'>Clik me and I don't care!</a>
      <span>Click me and I care!</span>
      <input type="checkbox">
  var parentElement = document.getElementById('parent');

  // We only handle 'click' event for <span> element and ignore the others.
  function handleClickForSpan(event) {
    if (event.target.matches('span')) {
      event.target.style.color = 'red';

  // We only handle 'click' event for <input type="checkbox"> and ignore the
  // others.
  function handleClickForCheckBox(event) {
    // Hide parent element (`li`) if we check the check box.
    if (event.target.matches('input')) {
      event.target.parentNode.style.display = "none";

  parentElement.addEventListener('click', handleClickForSpan);
  parentElement.addEventListener('click', handleClickForCheckBox);

Perhaps, my wording is not as cute as ちえさ せれな. I will let David Walsh explain it if you find my explanation confusing. Here’s his blog.

I finish the challenge this way. Have a look at the demo. I am off now!

I promise, I will explain this snippet incrementally but thoroughly.


  <div class="wrapper">
    <h2>LOCAL TAPAS</h2>
    <ul class="item-list">
      <li>Loading Tapas...</li>
    <form class="form">
      <input type="text" name="item" placeholder="Item Name" required>
      <input type="submit" value="+ Add Item">


Alright then, that’s it for today. I long for ちえさ せれな’s cute ponytail. I cannot wait any longer!