Emits in Vue 3: A Comprehensive Guide

In Vue 3, emits are a way to pass data from a child component to a parent component. Emits allow you to customize and reuse components by allowing you to specify the data that a component should emit when certain events occur. In this tutorial, we'll take a look at how to use emits in Vue 3 to build dynamic and reusable user interfaces.

To emit an event in Vue 3, you can use the this.$emit function in the component's methods. The $emit function takes two arguments: the name of the event, and the data that should be passed with the event.

For example, let's say you have a component called Button that renders a button element, and you want to allow the parent component to handle the click event:

<template>
  <button @click="handleClick">{{ label }}</button>
</template>

<script>
export default {
  props: {
    label: {
      type: String,
      default: 'Button',
    },
  },
  methods: {
    handleClick() {
      this.$emit('click');
    },
  },
};
</script>

In this example, the Button component is defined in the export default object, and the props option is used to define a label prop that allows you to customize the label of the button. The template contains a button element that displays the label prop and has a click event listener that calls the handleClick method. The handleClick method uses the $emit function to emit a click event.

To use the Button component in your application, you can use the <Button> element in a template and specify an event listener using the @ syntax:

<template>
  <Button @click="handleClick"></Button>
</template>

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

export default {
  components: {
    Button,
  },
  methods: {
    handleClick() {
      console.log('Button clicked');
    },
  },
};
</script>

In this example, the Button component is imported and registered in the components option, and the Button element is used in the template to render the Button component. The @click attribute is used to specify an event listener that listens for the click event emitted by the Button component. When the click event is emitted, the handleClick method is called, which logs a message to the console.

By using emits, you can customize and reuse components in different parts of your application. Whether you're building a simple form or a complex single-page application, emits are a key feature for building dynamic and reusable UIs with Vue 3.