How to define component name in Vue3 setup tag? [ duplicate ]

In Vue 3, when using the Composition API, the setup function is a new component option. Within this option, you cannot directly define the component name. The component name is typically defined when creating or registering the component, rather than inside the setup function.

Typically, the component name can be defined in two places:

1. When globally registering a component: When registering a component using the app.component method, you can directly specify the component name.

javascript
import { createApp } from 'vue';
import MyComponent from './MyComponent.vue';

const app = createApp({});
app.component('MyComponentName', MyComponent);
app.mount('#app');

Here, MyComponentName is the name you specify for the component.

1. When locally registering a component: When registering another component within a component using the components option, you can specify the name.

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

export default {
  components: {
    'MyComponentName': MyComponent
  }
}
</script>

In both cases, the name you use (MyComponentName) is used in the template to reference the component.

Although the setup function does not directly involve defining the component name, you can define and expose functions and data within it for use inside the component or in the template. For example:

vue
<template>
  <div>{{ greet }}</div>
</template>

<script>
import { ref } from 'vue';

export default {
  name: 'MyComponent',
  setup() {
    const greet = ref('Hello, Vue 3!');

    return { greet };
  }
}
</script>

In this example, although we define the greet data property within the setup function, the component name MyComponent is defined in the default export object. This is the recommended approach for defining component names when using the Composition API in Vue 3.