Getting Started with VUE3 for Beginners: Using Vue.js Components to Control Application State

Vue.js is a very popular JavaScript front-end framework that helps developers efficiently build interactive user interfaces and single-page applications (SPA). The recently released Vue3 version has better performance and richer features, and is increasingly widely used in front-end development. In this article, we will introduce some basic Vue.js knowledge and how to leverage Vue3 components to better control application state.

What is Vue.js

Vue.js is a data-driven front-end framework that abstracts DOM into a virtual DOM object and can perform data updates and DOM rendering very efficiently. Vue.js provides some very useful tools, such as data binding, componentization, transition animations, directives, and more. These tools make front-end development simpler, easier to use, and more efficient. The core features of Vue.js include:

• Data-driven: Vue.js abstracts the DOM into a data state. When the data changes, the DOM will be automatically updated
• Componentization: Vue.js splits the application into multiple components and uses a componentized approach for development and maintenance
• Two-way binding: Vue.js supports two-way data binding, that is, when the data changes, the view It will also be updated accordingly; vice versa
• Template syntax: Vue.js provides a set of concise and easy-to-read template syntax, which allows developers to build user interfaces more efficiently
• Life Cycle: Vue.js provides a complete component life cycle hook function, allowing developers to more finely control the behavior of components

New features of Vue3

Vue3 has several advantages over Vue2 Many improvements and enhancements. In general, Vue3 is faster, easier to use, and easier to maintain. The following are some new features of Vue3:

• Performance optimization: Vue3 introduces Proxy API, which can track data changes more accurately, thereby achieving a more efficient responsive system and greatly improving performance
• Combined API: Vue3 combines the option API and the composition API to provide a more flexible and easy-to-use component API, allowing developers to more freely organize and reuse component logic
• Static tree promotion : Vue3 improves static nodes and separates static nodes and dynamic nodes during compilation, which can greatly improve rendering performance
• Teleport component: Vue3 provides a Teleport component that can render sub-components outside the DOM tree. Location, providing more rendering scenarios
• Others: Vue3 also provides many other new features, such as Fragment components, global configuration API, optimized compilers, etc.

Use Vue3 components to control application state

Components are one of the core elements of Vue.js. Components can split the application into multiple reusable parts, allowing the code to More modular, easy to use and efficient. In Vue3, the idea of ​​componentization is more popular, and we can use components more flexibly for application development.

Create Vue components

In Vue3, we can use the Vue.component function to create Vue components. For example, we can create a HelloWorld component:

Vue.component('hello-world', {
  template: '<div>Hello World!</div>'
})

In the above code, we define a component named hello-world. The implementation logic is very simple, just returning a string "Hello World!". Inside the component, we can use the template attribute to define the component's template, or we can use the render function to generate the virtual DOM of the component.

Vue.component('hello-world', {
  render() {
    return Vue.h('div', 'Hello World!')
  }
})

Using components in applications

In Vue3, we can use components in applications. We only need to introduce components in the template option of the Vue instance.

<div id="app">
  <hello-world></hello-world>
</div>

In the above code, we introduced the hello-world component in the application template. When the application renders, Vue automatically resolves the component and renders the component into the template.

Component internal state management

In Vue3, we can also use responsive data in components. Reactive data allows us to manage the internal state of components more conveniently.

Vue.component('hello-world', {
  data() {
    return {
      count: 0
    }
  },
  methods: {
    increment() {
      this.count++
    }
  },
  render() {
    return Vue.h('div', [
      'Hello World!',
      Vue.h('button', { onClick: this.increment }, `Count: ${this.count}`)
    ])
  }
})

In the above code, we define a responsive data count in the hello-world component and implement a method increment to increase the value of the count. In the render function of the component, we use JSX syntax to generate the virtual DOM of the component. When the user clicks the button, the responsive data in the component automatically updates and the view updates accordingly.

Summary

In this article, we introduced some basic knowledge of the Vue.js framework and some new features of Vue3. We also covered how to use Vue3 components to have better control over application state. Through studying this article, I hope readers can have a deeper understanding of the world of Vue3 and bring a better development experience to front-end development.

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