Vue js event not picked up - vue.js

Question

I have just started experimenting with vue js and I am building a checkout form with it. I am also using Symfony 31 for the project. On the checkout/signup page I have an embedded collection of forms representing order items (each are subscription to a type of product). You can select multiple items by ticking a checkbox. You can also change the quantity. Unfortunately I cannot manage to pass the quantity update to the Vue instance. The entries are registered on render with the quantity 1, and if I change the quantity and then select the item, the price is calculated correctly, but the app registers this as a new entity. The binding with the quantity is not working. I will also need to add a similar field called frequency and I know I will have the same problem. Help?
Here is the js fiddle: https://jsfiddle.net/wavsu8xm/
Javascript:
var bus = new Vue();
var entriesComponent = Vue.component('entries', {
template: '#entries',
props: {
entries: [Array, Object],
selected: Array,
addons: Array,
frequencies: [Array, Object],
},
watch: {
selected: function(val, oldVal) {
bus.$emit('selected-changed', val);
},
}
});
new Vue({
el: '#app',
data: {
entries: [],
selected: [],
addons: [],
frequencies: [],
paymentConfig: {
advance: 25,
firstweek: 25,
ondelivery: 50,
},
weeks: 12,
},
components: {
'entriesComponent': entriesComponent,
},
created: function() {
// store this to use with Vue.set
var temp = this;
bus.$on('selected-changed', function(selected) {
// vm.$set deprecated
Vue.set(temp, 'selected', selected);
});
},
computed: {
totalAdvance: function() {
return (this.paymentConfig.advance * this.total) / 100;
},
totalFirstWeek: {
get: function() {
return (this.paymentConfig.firstweek * this.total) / 100;
},
},
onDeliveryPayment: {
get: function() {
return (this.paymentConfig.ondelivery * this.total) / (this.weeks * 100);
}
},
total: {
get: function() {
var sum = 0;
var weeks = this.weeks;
this.selected.forEach(function(item) {
sum += weeks * item.itemPrice * item.quantity;
});
console.log(sum);
return sum;
}
}
}
});
Template:
<section class="content">
<div class="row" id="app">
<div class="col-md-8">
<div class="box box-primary">
<div class="box-body">
<div class="row">
<div class="col-md-12">
<div class="form-group">
<label class="control-label required">Items</label>
<div class="col-md-12">
<entries :entries="{ 0 : { shareSize : 'Small', quantity : '1', itemPrice : '24', frequency : '' }, 1 : { shareSize : 'Medium', quantity : '1', itemPrice : '35', frequency : '' }, 2 : { shareSize : 'Large', quantity : '1', itemPrice : '46', frequency : '' } }"
:selected="selected"></entries>
<!-- component template -->
<template id="entries">
<div class="col-md-12">
<div class="form-group" v-for="(entry, key) in entries" v-bind:entry="entry">
<div class="form-group col-md-12">
<div class="col-md-12">
<div class="col-md-4">
<input type="checkbox" v-bind:value="entry" v-model="selected">
</div>
<div class="col-md-4">{{entry.shareSize}}</div>
<div class="col-md-4">{{'$ ' + Number(entry.itemPrice).toFixed(2) }}</div>
</div>
<div class="form-group col-md-12">
<div class="col-md-6">
<input type="number" v-model="entry.quantity" :value="entry.quantity" />
</div>
</div>
</div>
</div>
</div>
</template>
</div>
</div>
</div>
</div>
</div>
</div>
<div class="col-md-4">
<div class="box box-info">
<div class="box-body" style="padding:15px;">
<div class="container-fluid">
<div class="form-group">
<div class="control-label">
<label>Summary</label>
</div>
<div class="form-control" v-for="item in selected">
<span class="pull-left small-box-footer">{{ item.shareSize }}</span>
<span class="pull-right">{{ item.quantity + ' x $ ' + (item.itemPrice*item.quantity).toFixed(2)}}</span>
</div>
<div class="control-label">
<label>Payment plan</label>
</div>
<div class="col-md-12">
{{ '$ ' + totalAdvance.toFixed(2) }} - advance
</div>
<div class="col-md-12">
{{ '$ ' + totalFirstWeek.toFixed(2) }} - first week
</div>
<div class="col-md-12">
{{ '$ ' + onDeliveryPayment.toFixed(2) }}/ week on each of the {{ weeks }} weeks of the subscription
</div>
<div class="col-md-12 row">
<div class="control-label"><strong><span class="pull-left">Total</span><span class="pull-right">{{ '$ ' + total.toFixed(2) }}</span></strong></div>
</div>
<div class="col-md-12 row">
<div class="title"><strong><span class="pull-left">Total due now</span><span class="pull-right">{{ '$ ' + totalAdvance.toFixed(2) }}</span></strong></div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</section>

Answer 1

You are mutating your props directly which will get overwritten when the parent component re-renders, so you need to make a copy of them inside your component, which can be done inside the created method of your component:
created: function() {
// copy props to data
this.entriesCopy = this.entries;
this.selectedCopy = this.selected;
},
data: function() {
return{
entriesCopy: [],
selectedCopy: []
}
}
Now you just need to update your watcher:
watch: {
selectedCopy: function(val, oldVal) {
bus.$emit('selected-changed', val);
}
}
And your template:
//...
div class="form-group" v-for="(entry, key) in entriesCopy" v-bind:entry="entry">
//...
<input type="checkbox" v-bind:value="entry" v-model="selectedCopy">
to reflect the changes.
Here's the updated jsfiddle: https://jsfiddle.net/5pyw74h9/