Vue 2.x – TodoList案例以及总结

项目解构

├── node_modules
├── public
│   ├── favicon.ico
│   └── index.html
├── src
│   ├── assets
│   │   └── logo.png
│   │── components
│   │   ├── MyHeader.vue
│   │   ├── MyList.vue
│   │   ├── MyItem.vue
│   │   └── MyFooter.vue
│   │── App.vue
│   │── main.js
├── .gitignore
├── babel.config.js
├── package.json
├── README.md
├── package-lock.json

代码

main.js

// 引入vue
import Vue from 'vue'
// 引入App
import App from './App.vue'
// 关闭生产提示
Vue.config.productionTip = false
// 创建Vm
new Vue({
    el: '#app',
    render: h => h(App)
})

App.vue

<template>
  <div id="root">
    <div class="todo-container">
      <div class="todo-wrap">
        <MyHeader :addTodo="addTodo" />
        <MyList
          :todos="todos"
          :checkTodo="checkTodo"
          :deleteTodo="deleteTodo"
        />
        <MyFooter
          :todos="todos"
          :checkAllTodo="checkAllTodo"
          :clearAllTodo="clearAllTodo"
        />
      </div>
    </div>
  </div>
</template>

<script>
import MyHeader from "./components/MyHeader.vue";
import MyList from "./components/MyList.vue";
import MyFooter from "./components/MyFooter.vue";

export default {
  name: "App",
  components: { MyHeader, MyList, MyFooter },
  data() {
    return {
      todos: [
        { id: "1", title: "吃饭", done: true },
        { id: "2", title: "睡觉", done: false },
        { id: "3", title: "开车", done: true },
        { id: "4", title: "喝酒", done: false },
      ],
    };
  },
  methods: {
    // 添加一个新的todo
    addTodo(obj) {
      console.log(obj);
      this.todos.unshift(obj);
    },
    // 勾选或取消一个todo
    checkTodo(id) {
      this.todos.forEach((todo) => {
        if (todo.id === id) {
          todo.done = !todo.done;
        }
      });
    },
    // 删除一个todo
    deleteTodo(id) {
      this.todos = this.todos.filter((todo) => todo.id !== id);
    },
    // 全选，全不选
    checkAllTodo(done) {
      this.todos.forEach((todo) => {
        todo.done = done;
      });
    },
    // 清楚所有已完成的todo
    clearAllTodo() {
      this.todos = this.todos.filter((todo) => {
        return !todo.done;
      });
    },
  },
};
</script>

<style>
/*base*/
body {
  background: #fff;
}

.btn {
  display: inline-block;
  padding: 4px 12px;
  margin-bottom: 0;
  font-size: 14px;
  line-height: 20px;
  text-align: center;
  vertical-align: middle;
  cursor: pointer;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.2),
    0 1px 2px rgba(0, 0, 0, 0.05);
  border-radius: 4px;
}

.btn-danger {
  color: #fff;
  background-color: #da4f49;
  border: 1px solid #bd362f;
}

.btn-danger:hover {
  color: #fff;
  background-color: #bd362f;
}

.btn:focus {
  outline: none;
}

.todo-container {
  width: 600px;
  margin: 0 auto;
}
.todo-container .todo-wrap {
  padding: 10px;
  border: 1px solid #ddd;
  border-radius: 5px;
}
</style>

MyHeader.vue

<template>
  <div class="todo-header">
    <input
      type="text"
      placeholder="请输入你的任务名称，按回车键确认"
      @keyup.enter="add"
    />
  </div>
</template>

<script>
import { nanoid } from "nanoid";
export default {
  name: "MyHeader",
  props: ["addTodo"],
  methods: {
    add(event) {
      console.log(event);
      // 检验数据
      if (event.target.value === "") return alert("数据不能为空");
      // console.log(event.target.value);
      // 将用户的输入包装成一个TODO对象
      const todoObj = { id: nanoid(), title: event.target.value, done: false };
      // console.log(todoObj);
      // 通知App组件添加一个todo对象
      this.addTodo(todoObj);
      event.target.value = "";
    },
  },
};
</script>

<style scoped>
/*header*/
.todo-header input {
  width: 560px;
  height: 28px;
  font-size: 14px;
  border: 1px solid #ccc;
  border-radius: 4px;
  padding: 4px 7px;
}

.todo-header input:focus {
  outline: none;
  border-color: rgba(82, 168, 236, 0.8);
  box-shadow: inset 0 1px 1px rgba(0, 0, 0, 0.075),
    0 0 8px rgba(82, 168, 236, 0.6);
}
</style>

MyList.vue

<template>
  <ul class="todo-main">
    <MyItem
      v-for="todoObj in todos"
      :key="todoObj.id"
      :todo="todoObj"
      :checkTodo="checkTodo"
      :deleteTodo="deleteTodo"
    />
  </ul>
</template>

<script>
import MyItem from "./MyItem.vue";
export default {
  name: "MyList",
  components: { MyItem },
  props: ["todos", "checkTodo", "deleteTodo"],
};
</script>

<style scoped>
/*main*/
.todo-main {
  margin-left: 0px;
  border: 1px solid #ddd;
  border-radius: 2px;
  padding: 0px;
}

.todo-empty {
  height: 40px;
  line-height: 40px;
  border: 1px solid #ddd;
  border-radius: 2px;
  padding-left: 5px;
  margin-top: 10px;
}
</style>

MyItem.vue

<template>
  <li>
    <label>
      <input
        type="checkbox"
        :checked="todo.done"
        @change="handleCheck(todo.id)"
      />
      <span>{{ todo.title }}</span>
    </label>
    <button class="btn btn-danger" @click="handleDelete(todo.id)">删除</button>
  </li>
</template>

<script>
export default {
  name: "MyItem",
  // 声明接受todo对象
  props: ["todo", "checkTodo", "deleteTodo"],
  methods: {
    handleCheck(id) {
      // 通知App组件将对应的todo.done值取反
      this.checkTodo(id);
    },
    handleDelete(id) {
      if (confirm("确定吗？")) {
        // 通知App删除对应的todo
        this.deleteTodo(id);
      }
    },
  },
};
</script>

<style scoped>
/*item*/
li {
  list-style: none;
  height: 36px;
  line-height: 36px;
  padding: 0 5px;
  border-bottom: 1px solid #ddd;
}

li label {
  float: left;
  cursor: pointer;
}

li label li input {
  vertical-align: middle;
  margin-right: 6px;
  position: relative;
  top: -1px;
}

li button {
  float: right;
  display: none;
  margin-top: 3px;
}

li:before {
  content: initial;
}

li:last-child {
  border-bottom: none;
}

li:hover {
  background: gainsboro;
}

li:hover button {
  display: block;
}
</style>

MyFooter.vue

<template>
  <div class="todo-footer" v-show="total">
    <label>
      <input type="checkbox" :checked="isAll" @change="checkAll" />
      <!-- <input type="checkbox" v-model="isAll"/> -->
    </label>
    <span>
      <span>已完成 {{ doneTotal }}</span> / 全部 {{ total }}</span
    >
    <button class="btn btn-danger" @click="clearAll">清除已完成任务</button>
  </div>
</template>

<script>
export default {
  name: "MyFooter",
  props: ["todos", "checkAllTodo", "clearAllTodo"],
  computed: {
    total() {
      return this.todos.length;
    },
    doneTotal() {
      return this.todos.reduce(
        (pre, current) => pre + (current.done ? 1 : 0),
        0
      );
    },
    isAll() {
      return this.doneTotal === this.total && this.total > 0 ? true : false;
    },
    // 配合v-model实现全选
    // isAll: {
    //   get() {
    //     return this.doneTotal === this.total && this.total > 0 ? true : false;
    //   },
    //   set(value) {
    //     this.checkAllTodo(value);
    //   },
    // },
  },
  methods: {
    checkAll(event) {
      this.checkAllTodo(event.target.checked);
    },
    clearAll() {
      this.clearAllTodo();
    },
  },
};
</script>

<style scoped>
/*footer*/
.todo-footer {
  height: 40px;
  line-height: 40px;
  padding-left: 6px;
  margin-top: 5px;
}

.todo-footer label {
  display: inline-block;
  margin-right: 20px;
  cursor: pointer;
}

.todo-footer label input {
  position: relative;
  top: -1px;
  vertical-align: middle;
  margin-right: 5px;
}

.todo-footer button {
  float: right;
  margin-top: 5px;
}
</style>

TodoList案例总结

1. 组件化编码流程：

   ​ (1).拆分静态组件：组件要按照功能点拆分，命名不要与html元素冲突。

   ​ (2).实现动态组件：考虑好数据的存放位置，数据是一个组件在用，还是一些组件在用：

   ​ 1).一个组件在用：放在组件自身即可。

   ​ 2). 一些组件在用：放在他们共同的父组件上（状态提升）。

   ​ (3).实现交互：从绑定事件开始。

2. props适用于：

   ​ (1).父组件 ==> 子组件 通信

   ​ (2).子组件 ==> 父组件 通信（要求父先给子一个函数）

3. 使用v-model时要切记：v-model绑定的值不能是props传过来的值，因为props是不可以修改的！

4. props传过来的若是对象类型的值，修改对象中的属性时Vue不会报错，但不推荐这样做。