vue todoList 案例

添加，修改，删除

todoList效果图

Footer组件

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

<script>
export default {
  props: ["todos"],
  data() {
    return {};
  },
  computed: {
    total() {
      return this.todos.length;
    },
    isAll() {
      return this.doneTodo === this.total && this.total > 0;
    },
    doneTodo() {
      return this.todos.reduce((pre, todo) => {
        return pre + (todo.done ? 1 : 0);
      }, 0);
    },
  },
  methods: {
    checkAll(e) {
      this.$emit("checkAllTodo", e.target.checked);
    },
    clearAll() {
      this.$emit("clearAllTodo");
    },
  },
};
</script>

<style scoped>
.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>

Head组件

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

<script>
// npm i nanoid
import { nanoid } from "nanoid";
export default {
  data() {
    return {};
  },
  methods: {
    add(e) {
      if (!e.target.value.trim()) return;
      // 将用户输入包装成一个对象
      const todoObj = {
        id: nanoid(),
        title: e.target.value.trim(),
        done: false,
      };

      // 通知app直接去添加一个todo对象
      this.$emit("receive", todoObj);

      // 清空输入框
      e.target.value = "";
    },
  },
};
</script>

<style scoped>
.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(28, 81, 121, 0.8);
  box-shadow: inset 0 1px 1px rgba(0, 0, 0, 0.075),
    0 0 8px rgba(82, 168, 236, 0.6);
}
</style>

List 组件

<template>
  <!--  -->
  <ul class="todo-main">
    <!-- :todoObj="todoObj" 传值给子组件  -->
    <MyItem :todoObj="todoObj" v-for="todoObj in todos" :key="todoObj.id" />
  </ul>
</template>

<script>
import MyItem from "./MyItem.vue";
export default {
  components: { MyItem },
  props: ["todos"],
  data() {
    return {};
  },
};
</script>

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

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

MyItem 组件

<template>
  <li>
    <label>
      <input
        type="checkbox"
        :checked="todoObj.done"
        @change="handleChange(todoObj.id)"
      />
      <span v-show="!todoObj.isEdit">{{ todoObj.title }}</span>
      <input
        v-show="todoObj.isEdit"
        type="text"
        @blur="handBlur(todoObj, $event)"
        :value="todoObj.title"
        ref="inputRef"
      />
    </label>
    <button @click="handleDelTodo(todoObj.id)">删除</button>&nbsp;
    <button v-show="!todoObj.isEdit" @click="handleEdit(todoObj)">编辑</button>
  </li>
</template>

<script>
import pubsub from "pubsub-js";
export default {
  props: ["todoObj"],
  data() {
    return {};
  },
  methods: {
    handleChange(id) {
      // 通知app组件将对应的todo对象的done值取反
      this.$bus.$emit("checkTodo", id);
    },

    // 删除
    handleDelTodo(id) {
      if (confirm("确定删除吗")) pubsub.publish("delTodo", id);
    },

    // 编辑
    handleEdit(todo) {
      if (todo.hasOwnProperty.call("isEdit")) {
        todo.isEdit = true;
      } else {
        console.log("@@@");
        this.$set(todo, "isEdit", true);
      }
      this.$nextTick(() => {
        this.$refs.inputRef.focus();
      });
    },

    // 失去焦点 执行修改
    handBlur(todo, e) {
      todo.isEdit = false;
      if (!e.target.value.trim()) return alert("不能为空");
      this.$bus.$emit("updateTodo", todo.id, e.target.value);
    },
  },
};
</script>

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

App 主组件

<template>
  <div id="app">
    <Head @receive="addTodo" />
    <List :todos="todos" />
    <Footer
      :todos="todos"
      @checkAllTodo="checkAllTodo"
      @clearAllTodo="clearAllTodo"
    />
  </div>
</template>

<script>
import pubsub from "pubsub-js";

import Head from "./components/todoList/Head";
import Footer from "./components/todoList/Footer";
import List from "./components/todoList/List";

export default {
  name: "App",
  components: {
    Head,
    Footer,
    List,
  },
  data() {
    return { 
      todos: JSON.parse(localStorage.getItem("todos")) || [],
    };
  },
  // todos数据存到本地
  watch: {
    todos: {
      deep: true,
      handler(value) {
        localStorage.setItem("todos", JSON.stringify(value));
      },
    },
  },
  mounted() {
    this.$bus.$on("checkTodo", this.checkTodo);
    this.$bus.$on("updateTodo", this.updateTodo);
    // 订阅消息 msg（消息名字）, data（参数）
    this.pubId = pubsub.subscribe("delTodo", this.delTodo);
  },
  beforeDestroy() {
    this.$bus.$off("checkTodo");
    this.$bus.$off("updateTodo");
    pubsub.unsubscribe(this.pubId);
  },
  methods: { 
    // 添加todo
    addTodo(todoObj) {
      this.todos.unshift(todoObj);
    },

    // 取消选择todo
    checkTodo(id) {
      console.log("id", id);
      this.todos.forEach((todo) => {
        if (todo.id == id) todo.done = !todo.done;
      });
    },

    // 删除todo
    delTodo(_, id) {
      this.todos = this.todos.filter((todo) => {
        return todo.id != id;
      });
    },

    // 全选or全不选
    checkAllTodo(done) {
      this.todos.forEach((todo) => {
        todo.done = done;
      });
    },

    // 修改todo
    updateTodo(id, title) {
      this.todos.forEach((todo) => {
        if (todo.id === id) todo.title = title;
      });
    },

    // 清除所有已经完成的todo
    clearAllTodo() {
      this.todos = this.todos.filter((todo) => {
        return !todo.done;
      });
    },
  },
};
</script>

<style>
</style>

main.js

import Vue from 'vue'
import App from './App.vue'

Vue.config.productionTip = false

// Vue.prototype.$bus = new Vue()

new Vue({
  render: h => h(App),
  beforeCreate() {
    Vue.prototype.$bus = this
  },
}).$mount('#app')

效果图