How to encapsulate an own component in vue

Vue is a popular JavaScript framework for building modern, composable user interfaces. The basis of Vue is the component architecture. A component is a reusable block of code. The Vue framework makes it easy to decompose a page into multiple components. Moreover, Vue also allows developers to customize encapsulated components to meet specific business needs. This article will introduce how to encapsulate your own components in Vue so that they can be widely used by other developers or projects.

Requirements analysis

Before packaging components, the requirements need to be analyzed. This article takes a form verification component as an example to illustrate. The requirements are as follows:

1. Verify the format validity of mobile phone number, email address and password.
2. Provide different styles for validation results.
3. gives an error message.

Based on these requirements, we need to write a Vue component to implement form validation.

Component Encapsulation

Next, we will demonstrate how to encapsulate custom components in Vue.

Create component

First, we need to create a component. In Vue, components are created using the Vue.component() function. This function takes two parameters: the name of the component and the component's options object. The following is a simple example:

Vue.component('validation-form', {
  // 组件选项
})

In this example, we define a component named validation-form, which is an options object used to extend the functionality of the Vue component .

Template

Next, we need to define the template of the component. Templates are blocks of HTML code that display the content of a component. In the component's options object, the template can be defined through the template option. Here is a simple example:

Vue.component('validation-form', {
  template: '<div>表单验证组件</div>'
})

In this example, we define a template that contains only a simple HTML element <div>. <h3>Properties</h3> <p>Next, we need to define the properties of the component. A property is a type of data that allows passing from a parent component to a child component. In the component's options object, properties can be defined through the props option. Here is an example: </p> <pre class="brush:php;toolbar:false">Vue.component('validation-form', {   props: [     'email',     'password',     'phone'   ],   template: `     &lt;div&gt;       &lt;div&gt;电子邮件地址：{{ email }}&lt;/div&gt;       &lt;div&gt;密码：{{ password }}&lt;/div&gt;       &lt;div&gt;电话：{{ phone }}&lt;/div&gt;     &lt;/div&gt;   ` })</pre> <p> In this example, we define three properties: <code>email, password, and phone. In the template, we refer to the value of the attribute through the special syntax double curly braces {{ }}.

Events

Next, we need to define the events of the component. Events are actions triggered by a component to pass data back to the parent component. In the component's options object, events can be defined through the $emit() function. Here is an example:

Vue.component('validation-form', {
  props: [
    'email',
    'password',
    'phone'
  ],
  template: `
    <div>
      <input>
      <input>
      <input>
    </div>
  `
})

In this example, we use the v-model directive to bind data with form elements. Whenever the value of a form element changes, we use the $emit() function to trigger a custom event and use the prefix change- on the event name to pass data as required.

Specific implementation

With the understanding of the above basic concepts, you can then implement the components according to your needs. We will implement a form validation component with the following functions:

1. Verify the format of the email address and mobile phone number, and the validity of the password.
2. Provide different styles and give error messages based on the verification results.

First, we need to define the template and properties of the component:

Vue.component('validation-form', {
  props: [
    'email',
    'password',
    'phone'
  ],
  data() {
    return {
      // 绑定表单元素的值
      emailValue: this.email,
      passwordValue: this.password,
      phoneValue: this.phone,
      // 不同的样式，根据表单验证结果决定
      emailClass: '',
      passwordClass: '',
      phoneClass: '',
      // 错误信息
      emailError: '',
      passwordError: '',
      phoneError: ''
    }
  },
  methods: {
    // 验证电子邮件地址的函数
    validateEmail: function () {
      const regex = /^([\w\-\.]+)@([\w\-\.]+)\.(\w+)$/;
      if (regex.test(this.emailValue)) {
        this.emailClass = 'is-success';
        this.emailError = '';
      } else if (this.emailValue.length === 0) {
        this.emailClass = '';
        this.emailError = '';
      } else {
        this.emailClass = 'is-danger';
        this.emailError = '电子邮件地址格式错误!';
      }
    },
    // 验证密码的函数
    validatePassword: function () {
      const regex = /^(?=.*[A-Za-z])(?=.*\d)[A-Za-z\d]{8,}$/;
      if (regex.test(this.passwordValue)) {
        this.passwordClass = 'is-success';
        this.passwordError = '';
      } else if (this.passwordValue.length === 0) {
        this.passwordClass = '';
        this.passwordError = '';
      } else {
        this.passwordClass = 'is-danger';
        this.passwordError = '密码至少8个字符，包括字母和数字!';
      }
    },
    // 验证手机号码的函数
    validatePhone: function () {
      const regex = /^1[3456789]\d{9}$/;
      if (regex.test(this.phoneValue)) {
        this.phoneClass = 'is-success';
        this.phoneError = '';
      } else if (this.phoneValue.length === 0) {
        this.phoneClass = '';
        this.phoneError = '';
      } else {
        this.phoneClass = 'is-danger';
        this.phoneError = '手机号格式错误!';
      }
    }
  },
  template: `
    <div>
      <div>
        <label>电子邮件地址</label>
        <div>
          <input>
        </div>
        <p>{{ emailError }}</p>
      </div>

      <div>
        <label>密码</label>
        <div>
          <input>
        </div>
        <p>{{ passwordError }}</p>
      </div>

      <div>
        <label>手机号码</label>
        <div>
          <input>
        </div>
        <p>{{ phoneError }}</p>
      </div>
    </div>
  `
})

In the above code, we define a component with three properties, which are email, password and phone, these attributes will be bound by V-model to their respective form elements. In the component's options object, we define the following properties:

1. emailValue, passwordValue, phoneValue: used for Bind the value of the form element.
2. emailClass, passwordClass, phoneClass: used to bind different styles, determined based on the form verification results.
3. emailError, passwordError, phoneError: Used to provide binding for error messages.

We have also defined three user-defined functions to verify the validity of email addresses, passwords, and mobile phone numbers, and set different styles and error messages based on the verification results.

In the template, we use the V-model directive to bind data to form elements, and use the :class attribute to bind form elements with different styles as needed. Whenever the form element's value changes, we use the @blur event to trigger a custom event that authenticates the user, passing the data and event name.

Using Components

Now that we have successfully encapsulated our own Vue component, we can use it in other Vue applications. How to call this component? Just use the <validation-form></validation-form> tag in your Vue application to render your component and pass the required properties to the component.

<validation-form></validation-form>

In the above code, we are passing the properties bound to the component to the component. The view will display the input box and its status, as well as error messages, as shown in the image below.

Conclusion

Vue is an easy-to-use, flexible and powerful JavaScript framework, and suitable for building various types of applications and components. Custom components can help developers better organize and reuse code, and help improve code maintainability and scalability. In this article, we learned how to create custom components in Vue and how to use basic concepts such as properties, events, styles, etc. in components. We also use an instance component form validation to show how to implement a complete Vue component. We hope this article has been helpful to you and allowed you to better understand the characteristics and usage of Vue components, so that you can better use them to build web applications.