In recent years, Vue.js has emerged as a popular front-end JavaScript framework, thanks to its remarkable mix of ease, speed, and user-friendliness. Hold onto your headwear, though, because Vue.js 3 has upped its game with many fresh features and performance improvements. You're fortunate if you're a novice who wants to jump into Vue 3! You will be guided step-by-step through the ins and outs of setting up Vue 3 by this helpful article. Prepare to let your imagination run wild and change the front-end programming game! We will cover the following topics:
1. Introduction to Vue 3
What is Vue.js?
Vue.js is a progressive front-end JavaScript framework used for building user interfaces and single-page applications. It was created by Evan You in 2014 and has since gained popularity among developers due to its simplicity and ease of use. Vue.js allows developers to create reusable components, making it easy to build complex UIs.
What's new in Vue.js 3?
Vue.js 3 was released in September 2020 and comes with many new features and performance improvements. The new version of Vue.js is faster, smaller, and more maintainable than previous versions. Some of the new features in Vue.js 3 include:
- Improved rendering performance
- Smaller bundle size
- Improved TypeScript support
- Composition API for better code organization
- Better support for custom rendering
Why should you choose Vue.js?
Vue.js is a popular framework used by many developers due to its simplicity, performance, and ease of use. Some of the benefits of using Vue.js include:
- Easy to learn and use
- Simple and intuitive syntax
- Large community and ecosystem
- Excellent documentation and resources
- Great for building complex UIs
- High performance and fast rendering
2. Setting up Vue 3
Installing Vue 3
To install Vue 3, you can use the following command:
Creating a Vue project
The Vue CLI tool allows you to create a new Vue project with just a few simple commands. To create a new Vue project, follow these steps:
- Install the Vue Create CLI by running the following command:
npm i vue@latest - Initialize the project.
npm init vue@latest - Follow the prompts to select the features you want to include in your project, such as TypeScript or Router.
✔ Project name: … <your-project-name> ✔ Add TypeScript? … No / Yes ✔ Add JSX Support? … No / Yes ✔ Add Vue Router for Single Page Application development? … No / Yes ✔ Add Pinia for state management? … No / Yes ✔ Add Vitest for Unit testing? … No / Yes ✔ Add Cypress for both Unit and End-to-End testing? … No / Yes ✔ Add ESLint for code quality? … No / Yes ✔ Add Prettier for code formatting? … No / Yes Scaffolding project in ./<your-project-name>... Done. - Launch the project.
cd projet-name npm install npm run dev
Understanding the Vue 3 project structure
When you create a new Vue 3 project, you'll notice that it has a specific file structure that is optimized for Vue development. Here's an overview of the project structure:
src/: This directory contains your main application code, including components, templates, and styles.public/: This directory contains your public assets, such as yourindex.htmlfile and any static files.node_modules/: This directory contains all the third-party dependencies installed by npm.
3. Vue 3 Basics
Vue 3 SFC
Vue 3 Single File Component simplifies component development in Vue.js by allowing developers to define all the necessary code for a component in a single file.
The template, script, and styles can be written in HTML, JavaScript, CSS, Sass, or other styling languages. Using Single File Components, developers can write more maintainable and scalable code in their Vue.js projects.
<script setup>
</script>
<template>
<div></div>
</template>
<style></style>
Vue 3 Templates
Vue 3 templates are used to define the structure and layout of your application. Templates are written using HTML syntax and can include data bindings, conditional logic, and other dynamic features. Here's an example of a simple Vue 3 template:
<template>
<div>
<h1>{{ message }}</h1>
<p v-if="showMessage">This message is shown when showMessage is true.</p>
</div>
</template>
In this example, we have a template that displays a message variable and conditionally shows a message based on the value of the showMessage variable.
Vue 3 Components
Vue 3 components are reusable building blocks that can be used to create complex user interfaces. Components can be thought of as custom HTML elements that have their own data, templates, and behavior. Here's an example of a simple Vue 3 component:
<script setup>
</script>
<template>
<p>Welcome</p>
</template>
<style></style>
In this example, we've defined a new component called MyComponent with a template.
And we can import it elsewhere like that
//app.vue
<script setup>
import {MyComponent} from
</script>
<template>
<p>Welcome</p>
</template>
<style></style>
Vue 3 Directives
Vue 3 directives are special attributes that can be added to HTML elements to bind data or manipulate the DOM. Directives start with the v- prefix and can be used to do things like conditionally render content, bind values to form inputs and loop over arrays.
Here's an example of a few common Vue 3 directives:
<template>
<div>
<p v-if="showMessage">This message is shown when showMessage is true.</p>
<input v-model="message" />
<ul>
<li v-for="item in items" :key="item.id">{{ item.name }}</li>
</ul>
</div>
</template>
In this example, we've used the v-if directive to conditionally show a message, the v-model directive to bind a form input to a data property, and the v-for directive to loop over an array and render a list of items.
Basic Directives
Here are some of the most commonly used Vue 3 directives:
v-model: Two-way binding between a form input element and a data propertyv-ifandv-else: Conditionally render elements based on a boolean expressionv-for: Render a list of items based on an arrayv-show: Conditionally display an element based on a boolean expressionv-on: Attach event listeners to elementsv-bind: Dynamically bind an attribute to an expressionv-text: Render the text content of an element based on an expressionv-html: Render HTML content based on an expression
Vue 3 Computed Properties
Computed properties are used to calculate a value based on other properties in the Vue instance.
In Vue 3, computed properties are defined using the computed function. The computed function takes an object with a name for the computed property and a function that returns the computed value. Here's an example:
<script setup>
const firstName = ref("John");
const lastName = ref("Doe");
const fullname = computed(()=>`${firstName.value} ${lastName.value}`
</script>
In this example, we have a Vue instance with two data properties, firstName
and lastName, and a computed property called fullName. The **fullName**property uses string interpolation to combine the first and last names into a single string.
Vue 3 Watchers
Watchers are another important feature of Vue.js, and they allow you to watch for changes to a property or expression in the Vue instance and perform an action when it changes. Vue 3 continues to support watchers, but with some improvements over previous versions.
Watch
In Vue 3, watchers are defined using the **watch**function. The **watch**function takes the name of the property or expression to watch and a function to be called when the property or expression changes. Here's an example:
<script setup>
const x = ref(0)
const y = ref(0)
// single ref
watch(x, (newX) => {
console.log(`x is ${newX}`)
})
// getter
watch(
() => x.value + y.value,
(sum) => {
console.log(`sum of x + y is: ${sum}`)
}
)
// array of multiple sources
watch([x, () => y.value], ([newX, newY]) => {
console.log(`x is ${newX} and y is ${newY}`)
})
<script setup>
WatchEffect
watchEffect is a new API in Vue 3 that allows us to perform reactive side effects. It automatically detects the reactive dependencies used inside its callback function and tracks them.
This means that when any of these dependencies change, the watchEffect callback will be triggered. In other words, watchEffect is a shortcut for creating a watcher that automatically tracks all reactive dependencies inside its callback.
import { reactive, watchEffect } from 'vue'
const state = reactive({
count: 0,
message: ''
})
watchEffect(() => {
console.log(Count is ${state.count})
state.message = Count is now ${state.count}
})
In this example, the watchEffect callback logs the current count and updates the message whenever the count property changes. Since watchEffect automatically tracks the count property, we don't need to explicitly define it as a dependency.
Overall, watchEffect is a convenient and powerful API that can simplify our reactive programming code in Vue 3.
watch vs. watchEffect
watch and watchEffect are methods that allow us to perform side effects reactively. However, they differ in how they track their reactive dependencies.
- With
watch, only explicitly watched sources are tracked. The callback won't track anything accessed within it. Additionally, the callback only triggers when the source has changed, giving more precise control over when the callback should fire. This separates dependency tracking from the side effect, providing greater control. - On the other hand,
watchEffectcombines dependency tracking and side effects into one phase. During its synchronous execution, it automatically tracks every reactive property accessed. This method is more convenient and results in shorter code, but its reactive dependencies are less explicit.
Vue 3 Lifecycle Hooks
Vue 3 provides several lifecycle hooks that allow you to execute code at specific stages in a component's lifecycle, such as when the component is created, mounted, updated, or destroyed. In addition to the lifecycle hooks, Vue 3 also introduces the Composition API, which provides a new way to organize and reuse component logic.
Here are the main lifecycle hooks provided by Vue 3:
beforeCreate: Called before a component is createdcreated: Called after a component is created, but before it's mounted to the DOMbeforeMount: Called before a component is mounted to the DOMmounted: Called after a component is mounted to the DOMbeforeUpdate: Called before a component is updatedupdated: Called after a component is updatedbeforeUnmount: Called before a component is unmounted from the DOMunmounted: Called after a component is unmounted from the DOM
You can define these lifecycle hooks as methods on your Vue components, like this with the composition api:
<script setup>
import {ref, onMounted, onBeforeUnmount,onBeforeMount} from "vue
console.log('Component created.')
onBeforeMount(()=> {
console.log('Component mounted.')
})
onMounted(()=> {
console.log('Component mounted.')
})
onBeforeUnmount(() =>{
console.log('Component about to be unmounted.')
})
</script>
<template>
<p>Welcome</p>
</template>
In this example, we've defined a new component called MyComponent with a few lifecycle hooks. These hooks will be called when the component is created, mounted, and about to be unmounted.
4. Conclusion
Vue 3 is a powerful JavaScript framework that makes it easy to build complex web applications. By following the steps in this guide, you should have a good understanding of the basics of Vue 3 and how to get started with building your own Vue 3 applications.
If you want to learn more about Vue 3, be sure to check out the official Vue documentation, which has plenty of information and resources for learning Vue 3.
5. FAQs
Q1. What is Vue 3?
Vue 3 is a progressive JavaScript framework for building user interfaces.
Q2. What's new in Vue 3?
Vue 3 introduces several new features and improvements, including a new reactive system, improved performance, and a streamlined API.
Q3. Can I use Vue 3 with TypeScript?
Yes, Vue 3 has first-class TypeScript support and includes type definitions for all core APIs.
Q4. Is Vue 3 backward compatible with Vue 2?
While there are some breaking changes between Vue 2 and Vue 3, there is an official migration guide and many tools available to help you upgrade your Vue 2 code to Vue 3.
Q5. What kind of projects is Vue 3 best suited for?
Vue 3 is a versatile framework that can be used for a wide range of projects, from small web apps to large enterprise applications. It's particularly well-suited for projects that require a high degree of interactivity and dynamic user interfaces.