Vue encapsulates a TodoList example and implements the application of browser local cache

const storage = {
	set(key, value){
		window.sessionStorage.setItem(key, JSON.stringify(value));
	},
	get(key){
		return JSON.parse(window.sessionStorage.getItem(key));
	},
	remove(key){
		window.sessionStorage.removeItem(key);
	}
}

export default storage;

<template>
	<div class="todo">
		<header>
			<input type="text" placeholder="Enter..." v-model="keyword" @keydown.enter="handleList">
			TodoList
		</header>
		<!-- In Progress -->
		<h4>In progress...{{dolistNumber}}</h4>
		<template v-for="(item, index) in dolist" :key="index">
			<div class="dolist" v-if="!item.checked">
				<label :for="index +'l'">
					<input type="checkbox" v-model="item.checked" :id="index +'l'" @change="handleChecked">
					{{item.title}}
				</label>
				<span @click="cancalDo(index)">X</span>
			</div>
		</template>

		<!-- Completed -->
		<h4>Completed...{{dolist.length - dolistNumber}}</h4>
		<template v-for="(item, index) in dolist" :key="index">
			<div class="dolist" v-if="item.checked">
				<label :for="index +'ll'">
					<input type="checkbox" v-model="item.checked" :id="index +'ll'" @change="handleChecked">
					{{item.title}}
				</label>
				<span @click="cancalDo(index)">X</span>
			</div>
		</template>
	</div>
</template>

<script>
	import storage from '../storage.js';
	export default {
		name: "todoList",
		data() {
			return {
				keyword: "", // input options dolist: [],
			}
		},
		computed:{
			dolistNumber(){
				return this.dolist.filter(item => item.checked === false).length;
			}
		},
		methods: {
			handleChecked(){
				// Refresh after changing the status storage.set('dolist', this.dolist);
			},
			handleList() {
				if (this.keyword !== "") {
					this.dolist.push({
						title: this.keyword,
						checked: false,
					});
					this.keyword = "";
					storage.set('dolist', this.dolist);
				}
				
			},
			cancalDo(index) {
				// delete this this.dolist.splice(index, 1);
				storage.set('dolist', this.dolist);
			}
		},
		mounted(){
			let dolist = storage.get('dolist');
			if(dolist){
				this.dolist = dolist;
			}
		},

	}	
</script>

<style>
	.todo {
		margin: 400px auto;
		min-height: 300px;
		width: 800px;
		background-color: #eee;
	}

	.todo header {
		position: relative;
		text-align: center;
		height: 60px;
		line-height: 60px;
		font-size: 20px;
		border-bottom: 2px solid #fff;
	}

	.todo header input {
		position: absolute;
		left: 40px;
		top: 50%;
		transform: translateY(-50%);

		outline: none;
		line-height: 30px;
		border-radius: 15px;
		padding-left: 30px;
		border: 1px solid #999;
		font-size: 16px;
		width: 100px;
		transition: all .6s linear;
	}

	.todo header input:focus {
		width: 200px;
	}

	.dolist {
		padding: 20px;
		font-size: 16px;

	}

	.dolist label {
		cursor: pointer;
	}

	.dolist input {
		margin-right: 10px;

	}

	.dolist span:last-child {
		float: right;
		border: 1px solid gray;
		background-color: #999;
		color: #fff;
		border-radius: 50%;
		padding: 5px;
	}

	h4 {
		padding-bottom: 20px;
		text-align: center;
	}
</style>