Migrating "detect click outside" custom directive from Vue 2 to Vue 3 - vue.js

Question

Based on this question Detect click outside element and this answer https://stackoverflow.com/a/42389266, I'm trying to migrate the directive from Vue 2 to Vue 3. It seems that binding.expression and vnode.context not exists more. How can I make it work?
app.directive('click-outside', {
beforeMount (el, binding, vnode) {
el.clickOutsideEvent = function (event) {
if (!(el === event.target || el.contains(event.target))) {
vnode.context[binding.expression](event);
}
};
document.body.addEventListener('click', el.clickOutsideEvent);
},
unmounted (el) {
document.body.removeEventListener('click', el.clickOutsideEvent);
}
});

Answer 1

You can use binding.value instead like this:
const { createApp } = Vue;
const highlightEl = (color ) => (event, el) => {
if (el) {
el.style.background = color;
} else {
event.target.style.background = color;
}
}
const clearHighlightEl = (event, el) => {
if (el) {
el.style.background = '';
} else {
event.target.style.background = '';
}
}
const app = Vue.createApp({
setup() {
return {
highlightEl,
clearHighlightEl
}
}
})
app.directive('click-outside', {
mounted(el, binding, vnode) {
el.clickOutsideEvent = function(event) {
if (!(el === event.target || el.contains(event.target))) {
binding.value(event, el);
}
};
document.body.addEventListener('click', el.clickOutsideEvent);
},
unmounted(el) {
document.body.removeEventListener('click', el.clickOutsideEvent);
}
});
app.mount('#app')
<script src="https://unpkg.com/vue#3.0.0-rc.11/dist/vue.global.prod.js"></script>
<div id="app">
<h1 v-click-outside="highlightEl('yellow')" #click="clearHighlightEl">Element 1</h1>
<p v-click-outside="highlightEl('#FFCC77')" #click="clearHighlightEl">Element 2</p>
</div>

Answer 2

out of the context, there's an easier way in vue3 with composition.
Link to Vueuse ClickOutside (Vue 3)
Link to Vueuse ClickOutside(Vue 2)
<template>
<div ref="target">
Hello world
</div>
<div>
Outside element
</div>
</template>
<script>
import { ref } from 'vue'
import { onClickOutside } from '#vueuse/core'
export default {
setup() {
const target = ref(null)
onClickOutside(target, (event) => console.log(event))
return { target }
}
}
</script>

Answer 3

you can use ref to find out if the element contains the element clicked
<template>
<div ref="myref">
Hello world
</div>
<div>
Outside element
</div>
</template>
<script>
export default {
data() {
return {
show=false
}
},
mounted(){
let self = this;
document.addEventListener('click', (e)=> {
if (self.$refs.myref !==undefined && self.$refs.myref.contains(e.target)===false) {
//click outside!
self.show = false;
}
})
}
}
</script>

Answer 4

vue2 solution:
<script>
export default {
name: 'onClickOutside',
props: ['clickOutside'],
mounted() {
const listener = e => {
if (e.target === this.$el || this.$el.contains(e.target)) {
return
}
this.clickOutside()
}
document.addEventListener('click', listener)
this.$once('hook:beforeDestroy', () => document.removeEventListener('click', listener))
},
render() {
return this.$slots.default[0]
},
}
</script>
vue3:
<script>
import { getCurrentInstance, onMounted, onBeforeUnmount, ref, defineComponent } from 'vue'
export default defineComponent({
name: 'OnClickOutside',
props: ['clickOutside'],
setup(props, { emit, attrs, slots }) {
const vm = getCurrentInstance()
const listener = event => {
const isClickInside = vm.subTree.children.some(element => {
const el = element.el
return event.target === el || el.contains(event.target)
})
if (isClickInside) {
console.log('clickInside')
return
}
props.clickOutside && props.clickOutside()
}
onMounted(() => {
document.addEventListener('click', listener)
})
onBeforeUnmount(() => {
document.removeEventListener('click', listener)
})
return () => slots.default()
},
})
</script>