<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/OwlCarousel2/2.2.0/assets/owl.carousel.min.css">
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/OwlCarousel2/2.2.0/assets/owl.theme.default.min.css">

<div class="container mt-2">
  <div class="row">
    <div class="col-xs-12 col-md-5">
      <h1 class="text-xs-center text-md-left">Owl 2 Carousel Callback</h1>
      <p class="text-xs-center text-md-left">
        Swipe through the cards and watch the callback do its magic.
      </p>
      <h5>Here is a solution on how to get the correct index, without looking for the active class!</h5>
    </div>
    <div class="col-xs-12 col-md-7">

      <!-- Set up your HTML -->
      <div class="phone">
        <div class="owl-wrapper">
          <div class="row">
            <div class="col-xs-12">
              <div class="titlebar">
                Paymentinformation
              </div>
            </div>
          </div>
          <div class="loop owl-carousel owl-theme">
            <div>
              <div>Card1</div>
              <div class="card-number">
                <span>●●●● - </span>
                <span>●●●● - </span>
                <span>●●●● - </span>
                <span>1234</span>
              </div>
            </div>
            <div>
              <div>Card2</div>
              <div class="card-number">
                <span>●●●● - </span>
                <span>●●●● - </span>
                <span>●●●● - </span>
                <span>1234</span>
              </div>
            </div>
            <div>
              <div>Card3</div>
              <div class="card-number">
                <span>●●●● - </span>
                <span>●●●● - </span>
                <span>●●●● - </span>
                <span>1234</span>
              </div>
            </div>
            <div>
              <div>Card4</div>
              <div class="card-number">
                <span>●●●● - </span>
                <span>●●●● - </span>
                <span>●●●● - </span>
                <span>1234</span>
              </div>
            </div>
          </div>
          <div class="container">
            <div class="row">
              <div class="col-xs-12">
                <div class="card">
                  <div class="card-block jsCallback">
                    <div class="card-content loading">
                      <p><strong><span class="dummy-title"></span></strong></p>
                      <p>
                        <span class="dummy-parapgraph"></span>
                        <span class="dummy-parapgraph"></span>
                        <span class="dummy-parapgraph"></span>
                      </p>
                    </div>
                  </div>
                </div>
              </div>
            </div>
            <div class="row">
              <div class="col-xs-12">
                <div class="btn btn-primary btn-block jsBtn">
                  Button
                </div>
              </div>
            </div>
          </div>
        </div>
      </div>
    </div>
  </div>

</div>

@import url('https://fonts.googleapis.com/css?family=Lato:100,300,400,400i,700,900');
$color1: #4ac;
$color2: #4ac3be;
$amount: 10;
body,
html {
  font-family: 'Lato';
}

.phone {
  margin: 2em auto;
  width: 400px;
  max-width: 100%;
  background: #000;
  padding: 4em 1em;
  border-radius: 2em;
  box-shadow: 0 50px 50px -30px rgba(0,0,0,0.7), 0 50px 50px -50px rgba(0,0,0,0.7);
}

.titlebar {
  text-align: center;
  padding: 0.5em;
  background: $color2;
  font-size: 1.2em;
  color: white;
}

.card-block {
  transition: all 0.2s ease-out;
}

.card-content {
  text-align: justify;
  &.loading {
    animation: loading .4s linear infinite alternate;
    ;
  }
}

.dummy-title {
  display: inline-block;
  background: #ddd;
  width: 80%;
  height: 10px;
  border-radius: 5px;
}

.dummy-parapgraph {
  display: inline-block;
  background: #eee;
  width: 100%;
  height: 8px;
  border-radius: 5px;
  &:last-child {
    width: 60%;
  }
}

.owl-wrapper {
  background-color: rgba(240, 240, 240, 1);
  height: 600px;
}

.owl-carousel {
  & .card-number {
    opacity: 0.6;
    margin-top: 3em;
    text-align: right;
  }
  & .owl-item {
    background: white;
    padding: 1.5em;
    border-radius: 4px;
    opacity: 0.3;
    box-shadow: 0 4px 4px -1px rgba(0, 0, 0, 0.4);
    margin: 1em 0;
    transform: scale(0.9);
    transition: all 0.4s ease-out;
    &.center {
      opacity: 1;
      transform: scale(1);
      &:hover {
        box-shadow: 0 8px 16px -5px rgba(0, 0, 0, 0.4);
      }
    }
  }
}

.btn {
  background: $color1;
  border-color: transparent;
  transition: background 0.2s ease-out;
  &:hover,
  &:active,
  &:focus {
    background: darken($color1, $amount)!important;
    border-color: transparent!important;
  }
  &:active {
    background: darken($color1, $amount*2)!important;
  }
  &[disabled] {
    opacity: 0.3;
    -webkit-filter: grayscale(1);
    filter: grayscale(1);
  }
}

@keyframes loading {
  from {
    opacity: 0.3;
  }
  to {
    opacity: 1;
  }
}

$(document).ready(function() {
  var contentHtml = '<div class="card-content"><p><strong>{{ title }}</strong></p><p>{{ content }}</p></div>';
  var errorHTML = "<div class='alert-danger'>No Data available, Card4 has no data to see what happens when there is an error</div>";
  var callbackContainer = document.querySelectorAll(".jsCallback")[0];
  var loadingHTML = callbackContainer.innerHTML;
  var btn = document.querySelector(".jsBtn");

  /* Templating micro */
  var tmpl = function(t) {
    var code = 'with(o){return \'' + t.replace(/{{\s*(.+?)\s*}}/g, '\'+($1)+\'') + '\';}';
    return new Function('o', code);
  };
  var render = tmpl(contentHtml);

  /* callback FN */
  var afterFn = function(event) {
    var maxCount = event.item.count;
    var currentItem = (event.item.index - 2) % maxCount;
    if (currentItem <= 0 || currentItem > maxCount) {
      currentItem = 0;
    }
    callbackContainer.innerHTML = loadingHTML;
    btn.setAttribute('disabled', "disabled");

    /* Timeout to simulate loadingtimes */
    setTimeout(function() {
      console.log(typeof data[currentItem]);
      if (typeof data[currentItem] == 'object') {
        var finalHTML = render(data[currentItem]);
        callbackContainer.innerHTML = finalHTML;
        btn.removeAttribute('disabled');
      } else {
        callbackContainer.innerHTML = errorHTML;
      }
    }, 1000);
  }

  /* initialize owl */
  var $owl = $('.loop');
  $owl.owlCarousel({
    autoplay: true,
    autoplayHoverPause: true,
    autoplayTimeout: 3000,
    autoplaySpeed: 800,
    center: true,
    items: 1.3,
    stagePadding: 16,
    loop: true,
    margin: 16,
    onChanged: afterFn
  });

});

/* json data */
var data = [{
  title: "Cardtitle 1",
  content: "Card 4 ist not in this json, this should fire an error. Lorem ipsum dolor sit amet, consetetur sadipscing elitr."
}, {
  title: "Cardtitle  2",
  content: "Card 4 ist not in this json, this should fire an error. Lorem ipsum dolor sit amet, consetetur sadipscing elitr."
}, {
  title: "Cardtitle  3",
  content: "Card 4 ist not in this json, this should fire an error. Lorem ipsum dolor sit amet, consetetur sadipscing elitr."
}];