To do List with Vue js 2 using component or v-model - vuejs2

Question

Hello I have here one code with two "todo list" implementations in Vuejs but I have a problem.
1 Using a vue component i am getting a waring about how to use the parent variable.
2 Doing it on the main function I cannot keep the old value for the discard implementation.
please find the working code
Running! todo list in codepen
Vue.component('ntodo-item', {
template: '\
<transition name="fade">\
<div id="if" class="row" v-if="edit">\
<div class="col-md-7">\
<input class="form-control" v-model="title">\
</div>\
<div id="sssss" class="col-md-5">\
<button class="btn btn-danger roundButton" v-on:click="$emit(\'edit\')">Discard</button>\
<button class="btn btn-success roundButton" v-on:click="updateValue">Save</i></button>\
</div>\
</div>\
<div id="else" class="row" v-else>\
<div class="col-md-7">\
{{ title }}\
</div>\
<div id="ssaaas" class="col-md-5">\
<button class="btn btn-danger roundButton" v-on:click="$emit(\'remove\')">Remove</button>\
<button id="aaa" class="btn btn-default roundButton" v-on:click="$emit(\'edit\')">Edit</button>\
</div>\
</div>\
</transition>\
',
props: [
'title' ,
'edit'
],
methods: {
updateValue: function () {
this.$emit('input', this.title);
}
}
})
var app14 = new Vue({
el: '#app-14',
data: {
newTodoText: '',
newTodoText2: '',
todos: [
{
id: 1,
title: 'Do the dishes',
edit:0
},
{
id: 2,
title: 'Take out the trash',
edit:0
},
{
id: 3,
title: 'Mow the lawn',
edit:0
}
],
todos2: [
{
id: 1,
title: 'Do the dishes',
edit:0
},
{
id: 2,
title: 'Take out the trash',
edit:0
},
{
id: 3,
title: 'Mow the lawn',
edit:0
}
],
nextTodoId: 4,
nextTodoId2: 4
},
methods: {
addNewTodo: function () {
this.todos.push({
id: this.nextTodoId++,
title: this.newTodoText,
edit:0
})
this.newTodoText = ''
this.todos = _.orderBy(this.todos, 'id', 'desc');
},
editTodo: function (item){
// console.log(item.title)
item.edit^= 1
},
updateValue: function (item, newValue){
item.title=newValue
item.edit^= 1
},
addNewTodo2: function () {
this.todos2.push({
id: this.nextTodoId2++,
title: this.newTodoText2,
edit:0
})
this.newTodoText2 = ''
this.todos2 = _.orderBy(this.todos2, 'id', 'desc');
},
editTodo2: function (item){
console.log(item.title)
item.edit^= 1
},
deleteTodo2: function (item){
this.todos2.splice(item.id, 1);
},
updateValue2: function(text){
console.log(text);
}
}
})
.fade-enter-active, .fade-leave-active {
transition: opacity 0.3s, transform 0.3s;
transform-origin: left center;
}
.fade-enter, .fade-leave-to /* .fade-leave-active below version 2.1.8 */ {
opacity: 0;
transform: scale(0.5);
}
<script src="https://cdn.jsdelivr.net/npm/vue#2.5.13/dist/vue.js"></script>
<div class="col-md-12">
<div class="graybox">
<h5>app14</h5>
<div id="app-14">
`enter code here`<div class="row">
<div class="col-md-6">
<h5> todo list using "ntodo-item" component</h5>
<p>This one show me a warning because the child cannot edit the va passed by the parent but it is working and spected</p>
<input class="form-control"
v-model="newTodoText"
v-on:keyup.enter="addNewTodo"
placeholder="Add a todo"
>
<hr>
<ul>
<li
is="ntodo-item"
v-for="(todo, index) in todos"
v-bind:key="todo.id"
v-bind:title="todo.title"
v-bind:edit="todo.edit"
v-on:input="updateValue(todo, $event)"
v-on:remove="todos.splice(index, 1)"
v-on:edit="editTodo(todo)"
></li>
</ul>
</div>
<div class="col-md-6">
<h5> todo list update</h5>
<p> This one is working without any warn but I dont know how to discard changes. I dont want to create a temp var because I want to be able to edit all of them at the same time. </p>
<input v-model="newTodoText2"
v-on:keyup.enter="addNewTodo2"
placeholder="Add a todo"
class="form-control"
>
<hr>
<ul>
<transition-group name="fade" >
<li v-for="(todo2, index) in todos2":key="todo2.id">
<div id="if" class="row" v-if="todo2.edit">
<div class="col-md-7">
<input class="form-control" ref="todo2" v-model="todo2.title">
</div>
<div id="sssss" class="col-md-5">
<button class="btn btn-success roundButton" v-on:click="editTodo2(todo2)">ok</button>
</div>
</div>
<div id="else" class="row" v-else>
<div class="col-md-7">
{{todo2.title}}
</div>
<div id="ssaaas" class="col-md-5">
<button class="btn btn-danger roundButton" v-on:click="todos2.splice(index, 1)">Remove</button>
<button id="aaa" class="btn btn-default roundButton" v-on:click="editTodo2(todo2)">Edit</button>
</div>
</div>
</li>
</transition>
</ul>
</div>
</div>
</div>
</div>
</div>
.

Answer 1

Echoing my comment:
Create a local variable copy of your title prop and emit that variable's changes on edit. If they discard the edit just reset the local variable to the value of the title prop. Working example on CodeSandbox here.
Todo Item Component
<button class="btn btn-danger roundButton" #click="discardEdit">Discard</button>
...
data() {
return {
// our local copy
localTitle: null,
};
},
mounted() {
this.localTitle = this.title;
},
methods: {
updateValue: function() {
this.$emit("input", this.localTitle);
},
discardEdit: function() {
// just set local back to title prop value
this.localTitle = this.title;
this.$emit('edit');
},
}