v-navigation-drawer controlled state from a sub-component - vuetify.js

Question

I have a v-navigation-drawer which can be opened by clicking a button in a sub component.
So I changed v-model="drawer" to simply value="drawer" otherwise I get a warning about mutating a prop which makes sense (feels like doing some dirty angular double-way data binding ^^).
Here's the code:
layouts/default.vue:
<template>
<Header :toggleLeftMenu="toggleLeftMenu" />
<LeftMenu :show="showLeftMenu" :toggleLeftMenu="toggleLeftMenu" />
</template>
<script>
export default {
data() {
return {
showLeftMenu: true,
}
},
methods: {
toggleLeftMenu() {
this.showLeftMenu = !this.showLeftMenu;
},
}
}
</script>
components/layout/LeftMenu.vue:
<v-navigation-drawer
:value="show"
width="300"
clipped
fixed
app
>
This issue is that the drawer can be closed by clicking on the backdrop (on small devices). I need to plug the backdrop click to toggleLeftMenu prop, but according to the doc, this doesn't seem to be possible.
How can I achieve full control on the component? Is this #backdropClick event missing or something?
I tried to use #input but it creates an infinite loop which also makes sense.
Thanks
Using vuetify 2.6.1.

Answer 1

I changed v-model="drawer" to simply value="drawer" otherwise I get a warning about mutating a prop
This is not quite the right decision. Of course you should not use drawer as model, but you can create an internalDrawer prop in LeftMenu component, and leave the v-model where it is.
One of the possible ways to resolve your issue is to emit events from both sub-components into its parent.
So let's rewrite your LeftMenu component this way:
<template>
<v-navigation-drawer v-model="internalShow" width="200" clipped fixed app>
some drawer data
</v-navigation-drawer>
</template>
<script>
export default {
props: {
show: Boolean,
},
data() {
return {
internalShow: this.show,
};
},
watch: {
show (val) {
this.internalShow = val;
},
internalShow (val) {
if (val !== this.show) {
this.$emit("change-drawer-state");
}
},
},
};
</script>
In this case, every time when the internalShow state changes, an change-drawer-state event will be emitted.
Your Header component can be rewrited the same way:
<template>
<v-btn #click="$emit('change-drawer-state')">Drawer button</v-btn>
</template>
And this is the code of your parent component:
<template>
<div>
<Header #change-drawer-state="toggleLeftMenu" />
<LeftMenu :show="showLeftMenu" #change-drawer-state="toggleLeftMenu" />
</div>
</template>
<script>
import LeftMenu from "./LeftMenu";
import Header from "./Header";
export default {
components: {
LeftMenu,
Header,
},
data() {
return {
showLeftMenu: false,
};
},
methods: {
toggleLeftMenu() {
this.showLeftMenu = !this.showLeftMenu;
},
},
};
</script>
Both change-drawer-state event handlers are calling the same method - toggleLeftMenu and then the method changes show prop of navigation-drawer.
You can test this solution in a CodeSandbox playground.