Take you to understand Vue.js: easily create complex SPA

Take you to understand Vue.js: easily create complex SPA

"Understanding Vue.js: Creating Complex SPAs Made Easy" is a technical blog post that delves into the Vue.js framework and its role in single-page application (SPA) development. In this article, we will follow in the footsteps of Chen Yuan... to understand the core concepts of Vue.js step by step, including its declarative rendering, component system, routing management, state management, and comparison with other front-end frameworks.

First, we'll cover the basics of Vue.js, including its installation, basic syntax, and usage. Then, we'll dive into the core features of Vue.js, including its reactive data-binding system, and how components can be used to build complex user interfaces. Next, we will introduce how to use Vue Router and Vuex for routing and state management, and how to use Vue CLI to create and manage Vue.js projects.

At the end of the article, we will discuss the application of Vue.js in real projects. In addition, we will also evaluate the advantages and disadvantages of Vue.js and other front-end frameworks (such as React and Angular) to help readers choose the most suitable framework according to their needs.

Whether you are new to front-end development or an experienced developer, this article will provide you with in-depth and comprehensive knowledge of Vue.js to help you easily create complex single-page applications.

1 Introduction

1.1 Introduction to Vue.js

Vue.js is a progressive framework for building user interfaces. Compared to other heavyweight frameworks, Vue.js is designed to be easy to use while remaining flexible enough to handle complex Single Page Applications (SPA). Its core library focuses on the view layer, making it easy to integrate with other libraries or existing projects. Vue.js also provides advanced features such as routing, state management, and build tools, which are supported through officially maintained libraries and packages.

1.2 Basic Concepts of Single Page Application (SPA)

Single Page Application (Single Page Application, SPA) is a special kind of Web application. It dynamically rewrites the current page without refreshing the page during the interaction between the user and the application, instead of loading a new page in the traditional way. This approach avoids page reloads and provides a better user experience, making web application users feel more like they are using a local application.

In a SPA, all required code (HTML, JavaScript, CSS) is loaded once on a single page, or code can be dynamically added to a page in response to user actions. This requires the support of the front-end JavaScript framework. Vue.js is such a lightweight and powerful framework, which is very suitable for building complex SPA.

2 Understand the basics of Vue.js

2.1 Install Vue.js

The installation of Vue.js is very simple and can be installed through CDN links or NPM. Here, we'll cover how to install via NPM.

1. First, you need to install Node.js. Visit Node.js official website ↗ , download and install the appropriate version.
2. After installing Node.js, open a terminal or command line tool and enter the following command to install Vue.js:

npm install vue

In this way, Vue.js is successfully installed in your system.

2.2 Basic syntax of Vue.js

The basic syntax of Vue.js includes declarative rendering, conditional rendering, list rendering, etc. In the following sections, we will introduce these basic syntaxes in detail.

2.2.1 Declarative rendering

At its core, Vue.js is a system that allows declarative rendering of data into the DOM with a concise template syntax:

<div id="app">
  {
   
   { message }}
</div>

var app = new Vue({
    
    
  el: '#app',
  data: {
    
    
    message: 'Hello Vue!'
  }
})

2.2.2 Conditional and loop rendering

Using v-ifthe directive, we can render elements conditionally:

<p v-if="seen">Now you see me</p>

Using v-forthe directive, we can bind the data of an array to render a list:

<ul id="app">
  <li v-for="item in items">
    {
   
   { item.text }}
  </li>
</ul>

2.2.3 User input processing

To allow the user to interact with your application, we can use v-onthe directive to add an event listener that calls methods defined on our Vue instance:

<div id="app">
  <p>{
   
   { message }}</p>
  <button v-on:click="reverseMessage">Reverse Message</button>
</div>

var app = new Vue({
    
    
  el: '#app',
  data: {
    
    
    message: 'Hello Vue.js!'
  },
  methods: {
    
    
    reverseMessage: function () {
    
    
      this.message = this.message.split('').reverse().join('')
    }
  }
})

2.3 Vue instance and life cycle

Vue instances and lifecycles are very important concepts in understanding the basics of Vue.js.

The Vue instance is the root instance of a Vue.js application. By creating a Vue instance, you can implement functions such as data binding, template rendering, and event monitoring. Typically, you'll new Vue()create a Vue instance with , passing in an options object as a parameter.

After a Vue instance is created, it goes through different lifecycle stages, and each stage has a corresponding lifecycle hook function that can be used to execute code at a specific moment. The life cycle of a Vue instance can be divided into the following stages:

1. Creation phase: In this phase, the Vue instance is being created and initialized, and some initial setup is performed. Commonly used lifecycle hook functions are beforeCreateand created.
2. Mounting stage: At this stage, the Vue instance has completed the compilation and mounting process of the template, and can access the DOM elements. Commonly used lifecycle hook functions are beforeMountand mounted.
3. Update phase: In this phase, the data of the Vue instance has changed and a re-render is triggered. Commonly used lifecycle hook functions are beforeUpdateand updated.
4. Destruction phase: In this phase, the Vue instance is about to be destroyed and some cleanup operations are performed. Commonly used lifecycle hook functions are beforeDestroyand destroyed.

It should be noted that the lifecycle hook functions of the Vue instance exist in the form of callback functions, and you can define these hook functions in the options object of the Vue instance to perform related operations. At the same time, you can also access the properties and methods of the Vue instance in the hook function.

3 Core features of Vue.js

3.1 Declarative rendering

Vue.js adopts a declarative rendering method. By using Vue's template syntax, you can bind DOM and data to realize automatic synchronous update of data and views. You only need to pay attention to the changes of the data, and Vue will automatically update the corresponding views.

For example, in a Vue template, you can render a variable like this: { { message }}. When messagethe value of changes, the corresponding view will automatically update the rendering.

3.2 Componentized application construction

Vue.js supports componentized application building. By splitting the application into multiple reusable components, the development process can be simplified, code reuse and maintainability can be improved.

Vue components are extensible Vue instances with their own templates, logic, and styles. You can define a component and use it in the parent component's template. This componentized thinking allows you to split complex applications into smaller, independent components, making the code structure clearer and facilitating team collaboration.

3.3 Conditional rendering and list rendering

Vue.js allows you to render specific content based on conditions, this is called conditional rendering. You can use v-ifdirectives to control the showing and hiding of elements based on the true or false condition of an expression.

In addition, Vue.js also provides v-forinstructions for list rendering. You can loop through an array or object to dynamically generate a list of corresponding elements.

For example, you can use v-forthe directive to render a list like this:

<ul>
  <li v-for="item in items">{
   
   { item }}</li>
</ul>

This itemsdynamically generates multiple elements based on the elements in the array li.

With conditional rendering and list rendering, you can flexibly control the rendering of views according to different data situations.

4 Creating a SPA with Vue.js

4.1 Basic usage of Vue Router

Vue Router is the official routing manager provided by Vue.js. It allows you to load different components based on the path of the URL, and realize jumping and switching between pages without refreshing.

4.1.1 Configure routing

First, you need to install and use the Vue Router plugin in your Vue application. Before creating a Vue instance, you need to do some configuration, such as defining a routing table, specifying a default route, and so on.

When using Vue Router, you can Vue.useinstall it into your Vue instance via method. Then, create a new Vue Router instance, define the routing table and pass in Vue Router's routesoptions. You can specify paths and corresponding components in the routing table.

import Vue from 'vue'
import VueRouter from 'vue-router'
// 导入组件
import Home from './components/Home.vue'
import About from './components/About.vue'

// 安装 Vue Router 插件
Vue.use(VueRouter)

// 定义路由表
const routes = [
  {
    
     path: '/', component: Home },
  {
    
     path: '/about', component: About }
]

// 创建 Vue Router 实例
const router = new VueRouter({
    
    
  routes
})

new Vue({
    
    
  router,
  // 其它选项
}).$mount('#app')

4.1.2 Dynamic route matching

Vue Router also supports dynamic route matching, that is, using parameters in the route path.

You can use it in the routing table :to define the dynamic part, and then pass it in the component to $route.paramsget the value of the parameter.

const routes = [
  {
    
     path: '/user/:id', component: User }
]

<!-- User 组件 -->
<template>
  <div>
    <h2>User ID: {
   
   { $route.params.id }}</h2>
  </div>
</template>

4.1.3 Nested routes

Vue Router also supports nested routes, which allow you to define child routes under a parent route.

In the routing table, you can childrendefine sub-routes through options, specifying sub-routes and corresponding components.

const routes = [
  {
    
    
    path: '/user',
    component: User,
    children: [
      {
    
     path: '', component: UserHome },
      {
    
     path: 'profile', component: UserProfile },
      {
    
     path: 'settings', component: UserSettings }
    ]
  }
]

Nested routes can help you better organize and manage your application, making the code structure more readable and maintainable.

4.2 State Management Vuex

4.2.1 Basic concepts of Vuex

There are several core concepts in Vuex:

• State : the data in the application. In the state tree of Vuex, each state of the application can be represented by defining a state object.
• Getters : used to derive new data from the state. Similar to computed properties, it allows you to perform some complex logic calculations when getting state, and then return the result.
• Mutations : Methods for modifying state. Each mutation is a pure function that takes a state object and an optional payload, and performs some operation to update the state.
• Actions : Used to handle asynchronous logic and trigger mutations. Action submissions (mutations) can contain arbitrary asynchronous operations, and then trigger the corresponding mutation to update the state after completion.

4.2.2 How to use Vuex to manage state

Here are the basic steps to manage state with Vuex:

1. Install Vuex: Install the Vuex package in the Vue project, which can be installed through npm or yarn.
2. Create Vuex Store: In the entry file of the project, create a new Vuex.Store instance, and configure the Store by passing in an options object.
3. Define State: Define the initial state of the application in the Store, that is, the state object. State is stored as a single, predictable object.
4. Define Getters: If you need to derive some new data from the state, you can define Getters in the Store. Getters are actually computed properties that receive state as a parameter and return a derived value.
5. Define Mutations: Define mutations for modifying state. Each mutation has a string type (type) and a handler function (handler), the handler function receives the state object as the first parameter, and optionally receives a payload (payload) as the second parameter.
6. Define Actions: Define actions for asynchronously processing and submitting mutations. Actions can contain arbitrary asynchronous operations, including Ajax requests, etc., and update state by calling mutations.

Here is a simple sample code showing how to manage state with Vuex:

import Vue from 'vue'
import Vuex from 'vuex'

Vue.use(Vuex)

const store = new Vuex.Store({
    
    
  state: {
    
    
    count: 0
  },
  getters: {
    
    
    doubleCount: state => state.count * 2
  },
  mutations: {
    
    
    increment: (state, payload) => {
    
    
      state.count += payload
    }
  },
  actions: {
    
    
    incrementAsync: ({
     
      commit }, payload) => {
    
    
      setTimeout(() => {
    
    
        commit('increment', payload)
      }, 1000)
    }
  }
})

export default store

Using Vuex state in Vue components, you can use helper functions provided by Vuex (such as mapState, mapGetters, mapMutationsand mapActions) to simplify the writing of code.

4.3 Application of Vue CLI

Vue CLI is an official Vue.js-based scaffolding tool for quickly building Vue projects and developing, building, and deploying them.

4.3.1 Create a Vue.js project

Use the Vue CLI to quickly create a new Vue project. First, you need to have Vue CLI installed globally in your development environment. You can install it through npm or yarn.

After the installation is complete, you can use the vue command to create a new Vue project. Run the following command, then follow the prompts to select and configure:

vue create my-project

This will create a my-projectnew project folder called and generate the basic Vue project structure and configuration files in it. You can choose to manually configure specific features and plugins, or choose the default configuration to get your project started quickly.

4.3.2 Project configuration and management

Vue CLI provides an easy way to manage and configure your Vue projects. In the project folder, you can find a vue.config.jsconfiguration file called config for globally configuring the behavior and options of the Vue CLI.

By modifying vue.config.jsthe file, you can perform various configurations, such as customizing Webpack configuration, configuring proxy, modifying the build output path, etc.

Here is vue.config.jsthe content of an example file:

module.exports = {
    
    
  // 你的配置选项
  publicPath: '/my-project/',
  devServer: {
    
    
    proxy: {
    
    
      '/api': {
    
    
        target: 'http://localhost:8080',
        pathRewrite: {
    
    
          '^/api': ''
        }
      }
    }
  }
}

In this example, we modify the project's public path (publicPath) and the proxy configuration of the development server (devServer). You can customize other options according to your needs.

In addition to vue.config.jsfiles, Vue CLI also provides some commands to build, start and deploy projects. Such as using npm run servethe command to start the development server, using npm run buildthe command to build the production version, using vue-cli-serviceto run other custom commands, etc.

With the tools and options provided by Vue CLI, you can more easily manage and configure your Vue projects, improve development efficiency and prepare for projects.

5 Application of Vue.js in actual projects

Vue.js is widely used in practical projects. Here are some common application scenarios:

1. Single Page Application (SPA) : One of the most common use cases for Vue.js is building Single Page Applications. A Single Page Application is an application that loads content dynamically without reloading the entire page. Since Vue.js is lightweight and performant, it's perfect for building SPAs. The routing function, state management and component development of Vue.js make the development of SPA easier and more efficient.

2. Multi-page application (MPA) : In addition to SPA, Vue.js can also be used to build multi-page applications. A multi-page application is an application that contains multiple independent pages. Vue.js can treat each page as an independent Vue instance, and use Vue components and functions in each page. Through the modular development and component reuse of Vue.js, the development efficiency of multi-page applications can be improved.

3. Front-end framework integration : Vue.js can be integrated with other front-end frameworks, such as React and Angular. This integration allows developers to take full advantage of the advantages of each framework to achieve more flexible and powerful front-end development. For example, you can use Vue.js to build some UI components, and use React or Angular to develop other parts.

4. Mobile App Development : Vue.js can be used in conjunction with mobile app development frameworks such as Ionic and Framework7 to build cross-platform mobile apps. Efficient mobile application development can be achieved by using the componentized development method of Vue.js and the native mobile functions provided by the mobile application framework.

5. Background management system : Vue.js is also widely used in the development of background management systems. The data binding and component-based development features of Vue.js enable developers to quickly build an interactive and rich background management interface. At the same time, there are many third-party libraries and components in the Vue.js ecosystem that can be used to help developers build powerful background management systems.

In general, the application of Vue.js in actual projects is very flexible and diverse. It can be used to build various types of applications, including single-page applications, multi-page applications, mobile applications, and background management systems. The ease of use, flexibility, and high performance of Vue.js make it one of the go-to frameworks for many developers.

6 Comparison of Vue.js and other front-end frameworks

6.1 Comparison of Vue.js and React

Both Vue.js and React are currently popular front-end frameworks. They have many things in common and some differences:

Similarity:

1. Component-based development : Both Vue.js and React support component-based development, dividing the UI into independent reusable components, which helps to improve the maintainability and reusability of the code.

2. Virtual DOM : Both Vue.js and React use virtual DOM to manage elements on the page and render and update them efficiently, improving performance and user experience.

3. Responsive data binding : Both Vue.js and React provide a responsive data binding mechanism that automatically updates related views when data changes, enabling developers to write more concise and easy-to-understand code.

4. Ecosystem : Both Vue.js and React have a strong ecosystem, including many extension libraries, tools and third-party components, which can help developers solve more problems and needs.

difference:

1. Learning curve : Vue.js is relatively easy to learn because its syntax and concepts are more intuitive and simple. React, on the other hand, has a steeper learning curve and requires more time and effort to master its ideas and design patterns.

2. Rendering method : Vue.js uses template syntax to render components, and describes the interface by writing HTML templates and Vue instructions. React uses JSX syntax to write the structure and logic of components in JavaScript code. For developers who like template syntax, Vue.js is more attractive; for developers who prefer to put structure and logic together, React may be more suitable.

3. Standalone usability : Vue.js can be used directly in the page or integrated with existing projects. React is more inclined to build the entire application, and usually needs to cooperate with other tools (such as Webpack) to build and deploy the project.

4. Community and Ecosystem : React has a very large and active community and a rich ecosystem with many mature and reliable solutions and open source projects. The Vue.js community is also growing, and the ecosystem is getting more and more complete, but it is smaller than React.

The choice between using Vue.js or React depends on personal preference, project requirements and team situation. If you prefer concise and intuitive syntax and documentation, and an easy-to-use development experience, you can consider choosing Vue.js; if you have higher requirements for component-based development and a powerful ecosystem, and are willing to spend time learning its ideas and tool chains, then React may be more suitable for you.

6.2 Comparison of Vue.js and Angular

Vue.js and Angular are two popular front-end frameworks, they have some common characteristics, but also some differences:

Similarity:

1. Component-based development : Both Vue.js and Angular support component-based development, which divides the UI into independent reusable components to improve code maintainability and reusability.
2. Modularization : Both Vue.js and Angular use a modular approach to organize code, splitting the application into multiple logical modules for easy code management and maintenance.
3. Directives : Both Vue.js and Angular provide directives (such as v-model and ng-model) for two-way data binding, event binding, and style binding.

difference:

1. Learning curve : Vue.js is relatively easy to learn, with relatively simple concepts and syntax. While Angular has a steeper learning curve, it is a comprehensive framework that requires learning more concepts and complex APIs.

2. Rendering method : Vue.js uses template syntax to render components, and the instructions and expressions in the template can intuitively describe the interface. Angular uses HTML+CSS+TypeScript to build components, and writes structure, style and logic in Angular components.

3. Performance : Compared with Angular, Vue.js has higher performance. Vue.js uses virtual DOM and rendering optimization technology, which can effectively reduce the number of page re-rendering and improve application performance. On the other hand, Angular may cause performance degradation in larger-scale applications.

4. Libraries and Ecosystem : There are relatively few libraries and plugins for Vue.js, but they are gradually growing. Angular has a huge ecosystem, including officially maintained libraries, third-party libraries and tools, etc., providing more solutions and support.

5. Construction tools : Vue.js can be used directly on the page, or through Vue CLI for project construction and management. Angular has the Angular CLI, which provides a standardized set of CLI tools for quickly creating, building, and publishing Angular applications.

The choice between using Vue.js or Angular comes down to personal preference, project requirements, and team circumstances. If you like simple and intuitive syntax, smaller learning curve, and higher performance, you can choose Vue.js. If you need a complete framework and a huge ecosystem, prefer to use TypeScript, or develop larger-scale applications, then Angular may be more suitable for you.

7 Conclusion

In this article, we took an in-depth look at how to create complex single-page applications (SPAs) with Vue.js. We first understand the basic concepts of Vue.js, and then demonstrate how to implement data binding, componentization, routing management, and state management through examples. Vue.js' concise syntax, ease of use, and powerful ecosystem make it very popular in front-end development. Finally, we also covered some Vue.js best practices and frequently asked questions.

In summary, the five main points of the article include:

1. Basic concepts and structure of Vue.js.
2. How to implement data binding and componentization.
3. How to use Vue Router for route management.
4. How to use Vuex for state management.
5. Best practices and FAQs for Vue.js.

I hope this article can help you master Vue.js and make it easy for you to create your own single-page applications.