1. Introduction

This tutorial aims to guide you through animating elements in Vue.js using JavaScript hooks. By the end of this tutorial, you will have a firm understanding of:

• How to use Vue.js hooks to control animation timelines.
• How to create complex animations using Vue.js.

Prerequisites:

1. Basic knowledge of JavaScript.
2. A working understanding of Vue.js.
3. A text editor (VS Code, Sublime Text, Atom, etc.)
4. A modern browser for testing (Chrome, Firefox, etc.)

2. Step-by-Step Guide

Vue.js provides transition hooks that you can use to apply animations to your elements. These hooks include:

1. beforeEnter
2. enter
3. afterEnter
4. enterCancelled
5. beforeLeave
6. leave
7. afterLeave
8. leaveCancelled

These hooks will be fired at different stages of the animation. We'll use these hooks to create and control our animations.

3. Code Examples

Let's create a simple fade-in and fade-out animation using Vue.js hooks.

<template>
  <div id="app">
    <button @click="show = !show">Toggle</button>
    <transition
      name="fade"
      @before-enter="beforeEnter"
      @enter="enter"
      @after-enter="afterEnter"
      @enter-cancelled="enterCancelled"
      @before-leave="beforeLeave"
      @leave="leave"
      @after-leave="afterLeave"
      @leave-cancelled="leaveCancelled"
    >
      <p v-if="show">Hello</p>
    </transition>
  </div>
</template>

<script>
export default {
  name: 'App',
  data() {
    return {
      show: true,
    };
  },
  methods: {
    beforeEnter(el) {
      el.style.opacity = 0;
    },
    enter(el, done) {
      el.style.opacity = 1;
      done();
    },
    afterEnter(el) {
      console.log('After Enter');
    },
    enterCancelled(el) {
      console.log('Enter Cancelled');
    },
    beforeLeave(el) {
      console.log('Before Leave');
    },
    leave(el, done) {
      el.style.opacity = 0;
      done();
    },
    afterLeave(el) {
      console.log('After Leave');
    },
    leaveCancelled(el) {
      console.log('Leave Cancelled');
    },
  },
};
</script>

<style>
.fade-enter-active,
.fade-leave-active {
  transition: opacity 0.5s;
}
.fade-enter,
.fade-leave-to {
  opacity: 0;
}
.fade-enter-to,
.fade-leave {
  opacity: 1;
}
</style>

In the above example:

• The beforeEnter method will be fired before the animation starts. We set the element's opacity to 0 to make it invisible.
• The enter method gets fired during the animation. We set the element's opacity to 1, making it visible. The done callback is used to signal Vue.js that the animation is complete.
• The afterEnter method is called after the animation is complete.

The same goes for the leaving transitions. These methods are used to control the animation timeline and can be used to create more complex animations.

4. Summary

In this tutorial, we learned:

• How to use Vue.js hooks to control animation timelines.
• How to create a basic fade-in and fade-out animation using Vue.js hooks.

For further learning, you can explore:

• Vue.js documentation on Transitions
• MDN Web Docs on CSS Transitions

5. Practice Exercises

1. Create a slide-in and slide-out animation using Vue.js hooks.
2. Implement a bouncing animation for an element.
3. Create a complex animation using multiple Vue.js hooks.

Remember, practice is the key. Keep experimenting with different hooks and animations to get a better understanding.