Angular: Quick and easy animation on changed binding value

With ngAnimate, you can easily animate certain events (see directive support Show archive.org snapshot ). We'll make use of ngClass animations to style an element on changed binding value.

Say we have a slider and a separate details container. Each time the slider changes, we want to "flash" the details container by hiding it and fading it back in.

HTML

Add a custom class to the element you want to animate, i.e. the details container:

Copy<div class="details slide-index-{{ currentSlideIndex }}">
  {{ content }}
</div>

ngClass will be taking care of updating the details container's slide-index-N class; e.g. when the currentSlideIndex changes from 4 to 5, the slide-index-4 class is being removed and the slide-index-5 class is being added.

CSS

With ngAnimate included, ngClass will add certain animation classes Show archive.org snapshot . In the above example, it will add slide-index-4-remove and slide-index-5-add in addition to the classes themselves. We can reference these classes in CSS:

Copy.details {
  transition: opacity 1s;
  opacity: 1;
}

.details[class*="-remove"] {
  transition: none; // No transition on class removal -> instant hiding
  opacity: 0;
}

When the details container has the class slide-index-4-remove, the opacity is set to 0 without transition. The class is removed afterwards, having the container fade back in as defined for .details.