Vanilla Link Ativo

by Tiago Sousa

HTML

<button id="my_btn"><img src="http://placekitten.com.s3.amazonaws.com/homepage-samples/200/140.jpg" /></button>

CSS

.ativo > img {
  opacity: 0.5;
}

JavaScript

var btn = document.getElementById('my_btn');
btn.onclick = function() {
  if (this.classList.contains('ativo')) {
    this.classList.remove('ativo');
  } else {
    this.classList.add('ativo');
  }
  return false;
};