Fallthrough Attributes

In Vue, fallthrough attributes, also known as "v-bind="rest", allow us to bind all attributes that have not been explicitly declared as props to a single object.

This object can then be passed to a "child component", providing a clean way to manage attributes that are not explicitly defined as "props in the child component".

Overview of Fallthrough Attributes:

Fallthrough attributes work by using the v-bind="$attrs" directive on the child component passed from the Parent Component. This directive binds all the attributes that are not recognized as props or other special attributes directly to the child component. It's useful when creating wrapper components that enhance the functionality of their children.

Use Cases of Fallthrough Attributes:

Reusable Wrappers: Fallthrough attributes enable us to create wrapper components that add functionality or styling to their children while allowing customization of the underlying elements.
Forwarding Events: In addition to attributes, we can also forward events using the `$listeners` object, allowing events to propagate from the wrapper component to the child component.
Higher-Order Components: We can use fallthrough attributes to create higher-order components that enhance the behaviour of their children without tightly coupling them.

ParentComponent.vue

<template>
  <ChildComponent v-bind="childProps" custom-attribute="sam" />
</template>

<script>
import ChildComponent from './ChildComponent.vue';

export default {
  components: {
    ChildComponent
  },
  data() {
    return {
      childProps: {
        propA: 'Value A',
        propB: 'Value B'
      }
    };
  }
};
</script>

Access Fallthrough Attributes value using $attrs in Child Component:

ChildComponent.vue

<template>
  <div>
    <p>Prop A: {{ propA }}</p>
    <p>Prop B: {{ propB }}</p>
    <p>Custom Attribute: {{ customAttribute }}</p>
  </div>
</template>

<script>
export default {
  props: {
    propA: String,
    propB: String
  },
  data() {
    return {
      customAttribute: ''
    };
  },
  created() {
    // Since 'v-bind="rest"' was used in the parent component, 'custom-attribute' will be available in this component's data
    this.customAttribute = this.$attrs['custom-attribute'];
  }
};
</script>

In the ParentComponent, we have imported a child component named `ChildComponent`.
We use v-bind="childProps" to bind all attributes in the "childProps" object to the `ChildComponent`.
This means "propA" and "propB" will be passed as props to ChildComponent, and any other attributes, like "custom-attribute", will be available in the ChildComponent as "$attrs".
In the ChildComponent, we can access "custom-attribute" from "$attrs" in the "created lifecycle hook" since it wasn't explicitly defined as a prop.

Using fallthrough attributes helps to keep the parent component clean and concise while still providing flexibility in passing attributes to child components.

It's particularly useful when we want to pass down multiple attributes without having to explicitly declare them all as props in the child component.

<-- Emit

Scoping Styles -->