//Parent component
<template>
<childComp @onchangeData='changeData' />
</template>
<script>
setup() {
const state = reactive({
data: 'anything
});
function changeData(v){
state.data = v
}
return { changeData}
},
</script>
//Child
<template>
<button @click='change('hello')' />
</template>
<script>
setup() {
function change(v){
this.$emit('onchangeData', v)
}
return{change}
},
</script>
I am struggling to change the parents' reactive state from the child's button click. It's saying this.$emit is not a function. I tried many ways like using @onchangeData='changeData()' instead of @onchangeData='changeData', using arrow functions etc. But nothing works. Here, I wrote an example and minimal code to keep it simple. But I hope my problem is clear.
Look at following snippet, this is not the same in composition as in options API, so you need to use emit passed to setup function:
const { reactive } = Vue
const app = Vue.createApp({
setup() {
const state = reactive({
data: 'anything'
});
function changeData(v){
state.data = v
}
return { changeData, state }
},
})
app.component("ChildComp", {
template: `
<div>
<button @click="change('hello')">click</button>
</div>
`,
setup(props, {emit}) {
function change(v){
emit('onchangeData', v)
}
return { change }
},
})
app.mount('#demo')<script src="https://unpkg.com/vue@3/dist/vue.global.prod.js"></script>
<div id="demo">
<child-comp @onchange-data='changeData'></child-comp>
<p>{{ state.data }}</p>
</div>