Vuejs modal component cannot reference method - vue.js

Question

I have a modal dialog which is trying to use a method on the Vue app instance but getting the error
app.js:32117 [Vue warn]: Property or method "calcFees" is not defined on the instance but referenced during render. Make sure to declare reactive data properties in the data option.
The app declaration
Vue.component('sale', require('./components/Sale.vue'));
const app = new Vue({
el: '#app',
data: {
showModal: false
},
methods: {
calcFees: function (event) {
alert('GOOD');
}
}
});
Sale.vue component minimised for now
<template name="sale">
<input type="text" placeholder="Sale Price" class="form-control" #blur="calcFees">
</template>
The sale component is simply included in the main page here
<sale v-if="showModal"></sale>
The modal dialog works fine, displays the above text input however the above error is shown in the console and the blur event doesn't call the method.
It seems it has something to do with the component template, because i tested the blur event successfully by putting a text input in the main blade page directly.
Any ideas why it doesn't work in this way? I saw a comment somewhere about something to do with it being a <template> but it didn't explain how to fix.

Answer 1

Components cannot access methods declared in other components or the root Vue directly.
The problem with this code is that the calcFees method is declared in the root Vue, but you are trying to call it from the Sale.vue component.
There are several ways to make this work. One is you can move calcFees to the component. Another is you can $emit an event to the parent with whatever it needs to use in calcFees.
Sale.vue
<template name="sale">
<input type="text" v-model="price" placeholder="Sale Price" class="form-control" #blur="onSale">
</template>
<script>
export default {
data(){
return {
price: null
}
},
methods: {
onSale(){
this.$emit('sale', this.price)
}
}
}
</script>
Vue
<sale v-if="showModal" #sale="calcFees"></sale>
const app = new Vue({
el: '#app',
data: {
showModal: false
},
methods: {
calcFees: function (price) {
alert(price);
}
}
});