CODEWITHSUNDEEP
javascript
imparante
imparante

Reputation: 513

How can I show a spinner during a long JavaScript execution?

I have been playing with this for a long time now and cannot get a spinner in CSS to show when I press a button and then hide after the JavaScript function execution. This is a snippet of what I am attempting to do with pure JavaScript.

<button id="spinBtn" onclick="spinIt()">Spin it</button>
<div class="spinner" style="visibility:hidden;">

<script>
function spinIt() {
    document.getElementsByClassName("spinner").style.visibility = "visible";
    setTimeout(function () {
        // long code here
        document.getElementsByClassName("spinner").style.visibility = "hidden";
    }, 1); // give it a moment to redraw
}
</script>

http://jsfiddle.net/imparante/h9kLL1se/

Upvotes: 0

Views: 2184

Answers (2)

Tamil Selvan C
Tamil Selvan C

Reputation: 20209

Try

Instead of document.getElementsByClassName , use document.querySelectorAll and increase the setTimeout time interval.

And document.getElementsByClassName return array of match element. To pick the first element, use document.getElementsByClassName('spinner')[0]

function spinIt() {
  document.querySelectorAll(".spinner")[0].style.visibility = "visible";
  setTimeout(function() {
    // long code here
    document.querySelectorAll(".spinner")[0].style.visibility = "hidden";
  }, 1000); // give it a moment to redraw
}
.spinner {
  margin: 100px auto;
  width: 20px;
  height: 20px;
  position: relative;
}
.container1 > div,
.container2 > div,
.container3 > div {
  width: 6px;
  height: 6px;
  background-color: #333;
  border-radius: 100%;
  position: absolute;
  -webkit-animation: bouncedelay 1.2s infinite ease-in-out;
  animation: bouncedelay 1.2s infinite ease-in-out;
  /* Prevent first frame from flickering when animation starts */
  -webkit-animation-fill-mode: both;
  animation-fill-mode: both;
}
.spinner .spinner-container {
  position: absolute;
  width: 100%;
  height: 100%;
}
.container2 {
  -webkit-transform: rotateZ(45deg);
  transform: rotateZ(45deg);
}
.container3 {
  -webkit-transform: rotateZ(90deg);
  transform: rotateZ(90deg);
}
.circle1 {
  top: 0;
  left: 0;
}
.circle2 {
  top: 0;
  right: 0;
}
.circle3 {
  right: 0;
  bottom: 0;
}
.circle4 {
  left: 0;
  bottom: 0;
}
.container2 .circle1 {
  -webkit-animation-delay: -1.1s;
  animation-delay: -1.1s;
}
.container3 .circle1 {
  -webkit-animation-delay: -1.0s;
  animation-delay: -1.0s;
}
.container1 .circle2 {
  -webkit-animation-delay: -0.9s;
  animation-delay: -0.9s;
}
.container2 .circle2 {
  -webkit-animation-delay: -0.8s;
  animation-delay: -0.8s;
}
.container3 .circle2 {
  -webkit-animation-delay: -0.7s;
  animation-delay: -0.7s;
}
.container1 .circle3 {
  -webkit-animation-delay: -0.6s;
  animation-delay: -0.6s;
}
.container2 .circle3 {
  -webkit-animation-delay: -0.5s;
  animation-delay: -0.5s;
}
.container3 .circle3 {
  -webkit-animation-delay: -0.4s;
  animation-delay: -0.4s;
}
.container1 .circle4 {
  -webkit-animation-delay: -0.3s;
  animation-delay: -0.3s;
}
.container2 .circle4 {
  -webkit-animation-delay: -0.2s;
  animation-delay: -0.2s;
}
.container3 .circle4 {
  -webkit-animation-delay: -0.1s;
  animation-delay: -0.1s;
}
@-webkit-keyframes bouncedelay {
  0%, 80%, 100% {
    -webkit-transform: scale(0.0)
  }
  40% {
    -webkit-transform: scale(1.0)
  }
}
@keyframes bouncedelay {
  0%, 80%, 100% {
    transform: scale(0.0);
    -webkit-transform: scale(0.0);
  }
  40% {
    transform: scale(1.0);
    -webkit-transform: scale(1.0);
  }
}
<p>
  <button id="comboBtn" onclick="spinIt()">Combo it</button>
</p>

<div class="spinner" style="visibility:hidden">
  <div class="spinner-container container1">
    <div class="circle1"></div>
    <div class="circle2"></div>
    <div class="circle3"></div>
    <div class="circle4"></div>
  </div>
  <div class="spinner-container container2">
    <div class="circle1"></div>
    <div class="circle2"></div>
    <div class="circle3"></div>
    <div class="circle4"></div>
  </div>
  <div class="spinner-container container3">
    <div class="circle1"></div>
    <div class="circle2"></div>
    <div class="circle3"></div>
    <div class="circle4"></div>
  </div>
</div>

Upvotes: 2

deceze
deceze

Reputation: 522175

document.getElementsByClassName returns many elements (plural). At the very least you'd have to do this:

document.getElementsByClassName("spinner")[0].style.visibility = "visible";
                                          ^^^

Though you should either loop through this element list and make all spinners visible, or you should use a unique id for your spinner and get this one specific spinner via document.getElementById (singular).

Upvotes: 2

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