Animation for carousel with ng-boostrap and Angular 2

Question

I am using the carousel component with ng-bootstrap. I understand there's an open issue for a proper animation feature that works correctly with the angular 2 component life cycle right now (Github issue).

My question: is there a way to use CSS as a workaround for the animation?

I have put up a plunker that has fade in effect for the carousel, but not fade out.

.carousel-item.active{

    -webkit-animation: fadein 1.4s; 
       -moz-animation: fadein 1.4s; 
        -ms-animation: fadein 1.4s; 
         -o-animation: fadein 1.4s; 
            animation: fadein 1.4s;

}

@keyframes fadein {
    from { opacity: 0; }
    to   { opacity: 1; }
}

/* Firefox < 16 */
@-moz-keyframes fadein {
    from { opacity: 0; }
    to   { opacity: 1; }
}

/* Safari, Chrome and Opera > 12.1 */
@-webkit-keyframes fadein { 
    from { opacity: 0; }
    to   { opacity: 1; }
}

/* Internet Explorer */
@-ms-keyframes fadein {
    from { opacity: 0; }
    to   { opacity: 1; }
}

/* Opera < 12.1 */
@-o-keyframes fadein {
    from { opacity: 0; }
    to   { opacity: 1; }
}

Is there a way to make a fade out work? I have tried transition but failed.

Answer 1

Here are two animations I used in Angular 9, ng-bootstrap version 6.0.0. Easiest way is to give an entrance animation to .carousel-item.active. Animations are taken from animista.net/play/entrances. Just make sure you add the css to global styles.css

Animation 1

.carousel-item.active {
    -webkit-animation: flip-in-ver-left 0.5s cubic-bezier(0.250, 0.460, 0.450, 0.940) both;
            animation: flip-in-ver-left 0.5s cubic-bezier(0.250, 0.460, 0.450, 0.940) both;
}

 @-webkit-keyframes flip-in-ver-left {
    0% {
      -webkit-transform: rotateY(80deg);
              transform: rotateY(80deg);
      opacity: 0;
    }
    100% {
      -webkit-transform: rotateY(0);
              transform: rotateY(0);
      opacity: 1;
    }
  }
  @keyframes flip-in-ver-left {
    0% {
      -webkit-transform: rotateY(80deg);
              transform: rotateY(80deg);
      opacity: 0;
    }
    100% {
      -webkit-transform: rotateY(0);
              transform: rotateY(0);
      opacity: 1;
    }
  }

Animation 2

.carousel-item.active {
    -webkit-animation: tilt-in-fwd-tr 0.6s cubic-bezier(0.250, 0.460, 0.450, 0.940) both;
            animation: tilt-in-fwd-tr 0.6s cubic-bezier(0.250, 0.460, 0.450, 0.940) both;
}

 @-webkit-keyframes tilt-in-fwd-tr {
    0% {
      -webkit-transform: rotateY(20deg) rotateX(35deg) translate(300px, -300px) skew(-35deg, 10deg);
              transform: rotateY(20deg) rotateX(35deg) translate(300px, -300px) skew(-35deg, 10deg);
      opacity: 0;
    }
    100% {
      -webkit-transform: rotateY(0) rotateX(0deg) translate(0, 0) skew(0deg, 0deg);
              transform: rotateY(0) rotateX(0deg) translate(0, 0) skew(0deg, 0deg);
      opacity: 1;
    }
  }
  @keyframes tilt-in-fwd-tr {
    0% {
      -webkit-transform: rotateY(20deg) rotateX(35deg) translate(300px, -300px) skew(-35deg, 10deg);
              transform: rotateY(20deg) rotateX(35deg) translate(300px, -300px) skew(-35deg, 10deg);
      opacity: 0;
    }
    100% {
      -webkit-transform: rotateY(0) rotateX(0deg) translate(0, 0) skew(0deg, 0deg);
              transform: rotateY(0) rotateX(0deg) translate(0, 0) skew(0deg, 0deg);
      opacity: 1;
    }
  }

Answer 2

I wanted a fade in/fade out the transition between slides and found a simpler solution to this:

::ng-deep {
  .carousel-item {
    transition: opacity 0.7s ease !important;
    position: absolute !important;
    display: block !important;
    opacity: 0;
  }

  .carousel-item.active {
    position: relative !important;
    opacity: 1;
  }
}

If you don't want to use ::ng-deep (it seems that is going to be deprecated, or at least I read so last week in angular.io) you can use a global styles file that will reach all classes in all components

Answer 3

Alright, answering my own question. The following CSS hack will make the animation work just fine

ngb-carousel {
    width: inherit;
    height: inherit;
}


.carousel-inner {
    overflow: visible;
}

.carousel-item {
    display: flex !important;
    opacity: 0;
    visibility: hidden;
    transition: opacity 1.2s ease-in-out, visibility 1.2s;
    z-index: -1;
    position: absolute;
}

.carousel-item.active{
    opacity: 1;
    visibility: visible;
    z-index: 10;
}

.carousel-control-prev {
     z-index: 20;
}


.carousel-control-next {
     z-index: 20;
}

.carousel-indicators{
    z-index: 20;
}

Working Plunker