How to define directives on vue3 compositionAPI?

Question

How to define and use directives on vue3 composition api with the new syntactic sugar in SFC <script setup> format? With options API it used to be like this

import click_outside from "@/directives/click-outside.js";
export default {
  directives: {
    "click-outside": click_outside,
  }, 
  ...
}

click-outside.js

<script setup>
import {defineProps, onBeforeMount, onUnmounted, directive } from "vue";

const onBeforeMount = (el, binding) => {
  ...
};
const onUnmounted = (el) => {
 ...
};
</script>

I couldn't figure out the same counterpart code in composition API

Answer 1

Feature parity with regular script SFC is achieved in 3 different ways.

props argument from setup and props, emits, expose fields from component options are provided by using define... helpers.

context (only slots and attrs properties) argument from setup is provided by using use... helpers.

components and directives are indirectly provided by using imports of the same name.

The rest of features (e.g. name property) are still provided by script element that can coexist with script setup.