Vue.js 3.0 Tutorial

Vue.js 3.0 Component Advanced

Vue.js 3.0 Transitions & Animations

Vue.js 3.0 Reusable & Combinable

Vue.js 3.0 Advanced

Vue.js 3.0 Tools

Vue.js 3.0 Scale

Vue.js 3.0 Accessibility

Vue.js 3.0 Migrating from Vue2

Vue.js 3.0 Contribute Documentation

Vue.js 3.0 API References

Vue.js 3.0 Style Guide

Vue 3.0 Style Guide

Vue 3.0 Fragments

One of the great new features introduced with Vue 3 is the support for Fragments. Fragments are essentially multiple root nodes in your component template. In Vue 2.x, every component's template was required to have one and only one root element, but that restriction is no longer present in Vue 3.

Let's see how we can use Fragments in a Vue 3 component:

<template>
  <h1>Hello</h1>
  <h2>Vue 3</h2>
</template>

<script>
export default {
  name: 'MyComponent'
}
</script>

In this example, the template has two root nodes, h1 and h2. This was not possible in Vue 2, but in Vue 3 this is perfectly fine.

This feature is helpful in avoiding unnecessary wrapper elements and makes your HTML cleaner and more semantic.

It's worth noting that most styling and transitions which you might apply on the root node will now need to be applied individually to each top-level node. This is because there is no single root element to serve as the single source of styling or transitions when using Fragments.

Also, v-if and v-for directives can't be used directly on the Fragment. Instead, they should be used within a single node inside the Fragment.

Fragments are a straightforward feature in Vue 3 but can drastically simplify your component templates and the overall structure of your application.

Advantages of Using Fragments in Vue 3.0:
- Fragments allow grouping multiple elements without introducing an additional parent element in the DOM.
- Helps maintain cleaner and more semantic templates.
```
<template>
  <div>
    <p>Content 1</p>
    <p>Content 2</p>
  </div>
</template>
```
Using fragments:
```
<template>
  <>
    <p>Content 1</p>
    <p>Content 2</p>
  </>
</template>
```

Vue 3.0 Fragment Key Attribute:

When using fragments in a v-for loop, you can add a key attribute to help Vue identify each fragment.

<template>
  <div>
    <template v-for="(item, index) in items" :key="index">
      <p>{{ item.text }}</p>
    </template>
  </div>
</template>

Using fragments:

<template>
  <>
    <template v-for="(item, index) in items" :key="index">
      <p>{{ item.text }}</p>
    </template>
  </>
</template>

Handling Multiple Root Elements with Fragments in Vue 3.0:

Fragments enable rendering multiple root elements without a wrapper.

<template>
  <div>
    <p v-if="condition">Content A</p>
    <p v-else>Content B</p>
  </div>
</template>

Using fragments:

<template>
  <>
    <p v-if="condition">Content A</p>
    <p v-else>Content B</p>
  </>
</template>

Vue 3.0 Conditional Rendering with Fragments:

Fragments can be conditionally rendered based on a condition.

<template>
  <div v-if="showContent">
    <p>Conditional Content</p>
  </div>
</template>

Using fragments:

<template>
  <template v-if="showContent">
    <p>Conditional Content</p>
  </template>
</template>

Vue 3.0 Fragments and Reactivity:

Fragments do not introduce an additional element in the DOM, minimizing reactivity concerns.

<template>
  <>
    <p>{{ message }}</p>
  </>
</template>

<script>
export default {
  data() {
    return {
      message: 'Reactive Content',
    };
  },
};
</script>

Dynamic Fragments in Vue 3.0:
- Fragments can be dynamically generated based on the component's state.
```
<template>
  <template v-if="condition">
    <p>Dynamic Content</p>
  </template>
</template>
```

Vue 3.0 Fragments vs Div Wrappers:

Fragments avoid unnecessary wrapper elements, leading to cleaner markup.

Without fragments:

<template>
  <div>
    <p>Content A</p>
    <p>Content B</p>
  </div>
</template>

Using fragments:

<template>
  <>
    <p>Content A</p>
    <p>Content B</p>
  </>
</template>

Vue 3.0 Handling Transitions with Fragments:

Fragments seamlessly work with Vue 3.0 transition features.

<template>
  <transition name="fade">
    <template v-if="showContent">
      <p>Fading Content</p>
    </template>
  </transition>
</template>

Using fragments:

<template>
  <transition name="fade">
    <template v-if="showContent">
      <p>Fading Content</p>
    </template>
  </transition>
</template>

Vue 3.0 Fragments and JSX:

Fragments can be used seamlessly with JSX syntax.

<script setup>
import { ref } from 'vue';

const showContent = ref(true);

return () => (
  <>
    <p v-if="showContent">JSX Content</p>
  </>
);
</script>