Provide/inject function in Vue3: advanced component communication method

Vue is a popular open source JavaScript application framework that has become one of the important technologies for front-end development. Using the provide/inject function in Vue can implement advanced communication functions of components. This article will briefly introduce the provide/inject functions in Vue3 and their application in advanced component communication.

The provide and inject functions in Vue3

Vue3 is a new version of Vue.js that provides a variety of new functions and methods. New provide and inject functions are provided to replace props and events in Vue2. The provide and inject functions enable an ancestor component to pass data to all descendant components without explicitly passing data in each component. The provide function is defined in the ancestor component, and the inject function is called in the descendant component.

Use the provide function

The provide function is used to define data in ancestor components. The provide function accepts an object as a parameter and adds data as key-value pairs to the object. In the following example, we define a variable named "user" and add it as a key-value pair to the object of the provide function:

<template>
  <div>
    <GrandparentComponent>
      <ParentComponent>
        <ChildComponent />
      </ParentComponent>
    </GrandparentComponent>
  </div>
</template>

<script>
import { provide } from 'vue'
import GrandparentComponent from './GrandparentComponent.vue'

export default {
  components: { GrandparentComponent },
  setup() {
    const user = { name: 'John', age: 25 }
    provide('user', user)
  }
}
</script>

In the provide function, we use the provide function A "user" key is provided, corresponding to an object containing user information.

Use the inject function

The inject function is used to get data in descendant components. In the following example, we obtain the value of the "user" variable provided by the provide function in the ChildComponent's setup function:

<template>
  <div>
    <h4>ChildComponent</h4>
    <p>Name: {{ user.name }}</p>
    <p>Age: {{ user.age }}</p>
  </div>
</template>

<script>
import { inject } from 'vue'

export default {
  setup() {
    const user = inject('user')
    console.log(user) // { name: 'John', age: 25 }
    return { user }
  }
}
</script>

In ChildComponent, we use the inject function to obtain the value of the 'user' variable , and stores it in a constant named user. In the template, we can directly access the properties of the user variable.

Advantages of provide and inject functions

In the traditional props and events method, data needs to be passed to each component layer by layer. In large applications, this is very tedious and error-prone. However, using the provide and inject functions we can pass data around more easily. The provide and inject functions can pass data throughout the component tree, allowing data to flow between components.

In the provide and inject functions, data is passed in the reverse direction. Unlike props and events, the data provided by the provide and inject functions are not restricted to descendant components. Throughout the component tree, descendant components can easily obtain the provided data. Additionally, because the provide and inject functions are reactive, you can use them with many other Vue3 features and APIs.

Conclusion

This article introduces the provide and inject functions in Vue3 and their application in advanced component communication. By using these functions, you can easily pass data throughout the component tree. Thank you for reading this article, I hope it will be helpful to your work in Vue development.

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