Contemporary web applications are becoming increasingly complex, which means building code that is maintainable, reusable, and easy to develop is even more critical. The componentization framework in Vue3 is one of the very powerful ways to achieve this goal, and parent components and child components, as an important aspect of it, play a very key role.
This article will briefly introduce the difference between parent components and child components in Vue3, as well as several possible methods of passing parameters. At the same time, we will also use code examples to help you better understand the specific operations of communication between components in Vue3.
Parent and Child Components
Vue3 adopts a component-based idea in design, that is, it divides different page elements into its own components, and each component can run independently. In a component, a parent component can contain one or more subcomponents, and data and methods can be passed between subcomponents. At the same time, the logic and UI structure of the components are encapsulated in their respective scopes, making the entire application easier to maintain and upgrade.
So, what is a parent component and what is a child component?
Parent Component: A component that contains one or more child components. Subcomponent: A component introduced and used by a parent component.
The difference between parent components and child components
Parent and child components in Vue3 differ in the following ways:
-
Scope: Parent components can access the global, while child components can only access the scope of the component they belong to.
-
Data communication: the parent component can pass data directly to the child component, and the child component can use props to receive; however, if the data of the child component is modified, the update needs to be triggered by methods such as events.
-
Lifecycle: Parent components and child components have different lifecycles, and you should pay attention to the use of their hook functions when building components.
Several ways to transfer data from parent component to child component
- Props
Using the props attribute, developers can pass values from parent components to child components.
The specific implementation method is as follows:
parent component:
<template>
<div>{
{ message }}</div>
</template>
<script>
export default {
name: 'ChildComponent',
props: {
message: String
}
}
</script>
2. Pass data from the parent component to the child component
When using the label of the child component in the template of the parent component, the data that needs to be passed to the child component is bound to the props attribute of the child component through the v-bind directive. For example, we can pass a data named parentMessage to the child component in the parent component:
<template>
<child-component :message="parentMessage"></child-component>
</template>
<script>
import ChildComponent from './ChildComponent'
export default {
name: 'ParentComponent',
components: {
ChildComponent
},
data () {
return {
parentMessage: 'Hello from Parent'
}
}
}
</script>
In the above code, when using the label of the child component, the parentMessage data in the parent component is bound to the message property of the child component through v-bind.
3. Use props data in subcomponents
In the template of the child component, we can directly use the data defined in props to render the view. For example, this data can be used in the child component's template as follows:
<template>
<div>{
{ message }}</div>
</template>
<script>
export default{
name: 'ChildComponent',
props: {
message: String
}
}
</script>
In the above code, we can directly use the data defined in props to render the view through { { message }}.
The above is the difference between the parent component and the child component in Vue3 and the introduction of the parameter passing method. Hope this blog can be helpful to you!