Unlock the Power of JavaScript in Vue Transitions

When it comes to creating engaging user experiences, animations and transitions play a vital role. JavaScript can be used alone or in conjunction with CSS to unlock a new level of control and flexibility in your UI.

Event Hooks: The Key to Unlocking JavaScript’s Potential

The transition tag comes equipped with event hooks, which allow JavaScript to influence transitions. These hooks operate on the element, similar to transition classes in CSS, enabling you to execute JavaScript code at every stage of attachment or removal of the HTML element from the DOM.

Six Event Hooks to Master

• @before-enter: Run JavaScript code for one frame before the element is attached to the DOM
• @enter: Execute code as the element is attached to the DOM
• @after-enter: Run code after the element has been attached to the DOM
• @enter-cancelled: Abort the animation and clear its playback
• @before-leave: Run JavaScript code for one frame before the element is removed from the DOM
• @leave: Execute code as the element is removed from the DOM
• @after-leave: Run code after the element has been removed from the DOM
• @leave-cancelled: Run code if the animation is canceled

Combining Event Hooks with CSS

Let’s examine an example that combines event hooks in JavaScript with CSS to create animations. We’ll use @keyframes in CSS to define styles for both attaching and removing the element from the DOM.

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

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

Then, we’ll create methods for our event hooks, adding comments to the console and styles to the element at each stage of attachment and removal.

export default {
  methods: {
    beforeEnter(el) {
      console.log('Before enter');
      el.style.opacity = 0;
    },
    enter(el) {
      console.log('Enter');
      el.style.animation = 'attach 1s';
    },
    afterEnter(el) {
      console.log('After enter');
      el.style.opacity = 1;
    },
    beforeLeave(el) {
      console.log('Before leave');
      el.style.opacity = 1;
    },
    leave(el) {
      console.log('Leave');
      el.style.animation = 'emove 1s';
    },
    afterLeave(el) {
      console.log('After leave');
      el.style.opacity = 0;
    }
  }
}

Using Event Hooks in Isolation

The beauty of event hooks lies in their flexibility. You can use any of the hooks in isolation to run JavaScript code, without needing to attach all the hooks to the transition tag.

JavaScript-Only Animations

If you’re using JavaScript hooks without any CSS, simply add :css="false" to your transition tag. This tells the transition tag to ignore CSS and rely solely on JavaScript.

The Power of JavaScript in Vue Transitions

With JavaScript, you can exert complete control over elements through the DOM, giving you the flexibility to precisely manipulate elements and create better, more scalable applications for your users.

Learn more about Vue transitions and animations