How to change the state of a vue when you click the check button - mongodb

Question

I am creating a Todo Application using Vue.js, Express.js, and MongoDB.
I want to change the state of the fields that appear as v-for through the checkbox.
The code I want is to change the state of the text when the checkbox is checked and to show another element with v-if.
Here is the code I wrote: But it does not work.
If I have the wrong code, please help me.
List Component
<template>
<div class="todos">
<div v-for="todo in todos" v-bind:key="todo._id" class="todo">
<div>
<input type="checkbox" v-model="todo.done" v-on:click="completeTodo(todo)">
<del v-if="todo.done">{{todo.title}}</del>
<strong v-else>{{todo.title}}</strong>
</div>
</div>
</div>
</template>
<script>
export default {
data () {
return {
todos: {}
}
},
created () {
this.$http.get('/api/todos')
.then((response) => {
this.todos= response.data
})
},
methods: {
completeTodo (todo) {
todo.done = !todo.done
}
}
}
</script>

Answer 1

You don't need v-on:click="completeTodo(todo)". v-model is already doing the trick for you. Also, the todos in your code should be defined and instantiated as array not an object.
v-model is used for two way data binding. That means, whatever data you pass from your code will be bound to the checkbox value in this case and whenever a change is made from UI and value of checkbox is altered by user, that will be captured in v-model variable. v-model is a combo of :value prop and #change event in case of checkbox, hence, it is able to update data in both the ways.
Please refer this snippet.
var app = new Vue({
el: '#app',
data: {
todos: [
{
id: 1,
title: 'Study',
done: false
},
{
id: 2,
title: 'Work',
done: false
},
{
id: 3,
title: 'Play',
done: false
}
]
}
})
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.js"></script>
<div id="app">
<div class="todos">
<div v-for="todo in todos" :key="todo.id">
<div>
<input type="checkbox" v-model="todo.done"/>
<del v-if="todo.done">{{todo.title}}</del>
<strong v-else>{{todo.title}}</strong>
</div>
</div>
</div>
</div>