Updating animation-duration in Javascript

Question

After changing the animation-duration (or in this case, -webkit-animation-duration) property via JavaScript with setProperty(\"-webkit-animation-

Answer 1

It's not easy to restart CSS animation or change its parameter. However, I found some trick. See the following code. I separated the animation parameters into the class, which I add / remove. Plus the trick found in CSS-Tricks article and it works:

$(document).ready(function() {
  $('#slow-btn').click(function(){
    $('#testdiv').removeClass("testanimation");
    $('#testdiv').css("-webkit-animation-duration", "5s");
    $('#testdiv').get(0).offsetWidth = $('#testdiv').get(0).offsetWidth;
    $('#testdiv').addClass("testanimation");
  });
  $('#fast-btn').click(function(){
    $('#testdiv').removeClass("testanimation");
    $('#testdiv').css("-webkit-animation-duration", "1s");
    $('#testdiv').get(0).offsetWidth = $('#testdiv').get(0).offsetWidth;
    $('#testdiv').addClass("testanimation");
  });
});

#testdiv {
    display: block;
    position: absolute;
    left: 100px;
    width: 100px;
    height: 100px;
    background: red;
}
.testanimation {
    -webkit-animation: myanimation 2s linear alternate infinite;
    animation: myanimation 2s linear alternate infinite;
}
@-webkit-keyframes myanimation {
    from {left: 100px;}
    to {left: 400px;}
}
@keyframes myanimation {
    from {left: 100px;}
    to {left: 400px;}
}