Vue+TypeScript中处理computed方式

<template>
  <input v-model="name">
</template>
 
<script>
import Vue from 'vue'
import Component from 'vue-class-component'
 
@Component
export default class HelloWorld extends Vue {
  firstName = 'John'
  lastName = 'Doe'
 
  // Declared as computed property getter
  get name() {
    return this.firstName + ' ' + this.lastName
  }
 
  // Declared as computed property setter
  set name(value) {
    const splitted = value.split(' ')
    this.firstName = splitted[0]
    this.lastName = splitted[1] || ''
  }
}
</script>

<template>
  <el-table border :data="data" style="width: 100%;" height="400" @selection-change="selectChange">
    <el-table-column type="selection" width="55"></el-table-column>
    <el-table-column prop="code" label="编码"></el-table-column>
    <el-table-column prop="name" label="名称"></el-table-column>
  </el-table>
</template>

<script>
export default {
  name: 'hierarchy-table',
  props: {
    value: {
      type: Array,
      required: true
    },
    skipCodes: {
      type: Array
    }
  },
  data() {
    return {
    };
  },
  computed: {
    data() {
      return this.skipCodes ? this.value.filter(it => !this.skipCodes.includes(it.code)) : this.value;
    }
  },
  methods: {
    selectChange(selection) {
      this.$emit('selection-change', selection);
    }
  }
};
</script>

<template>
  <el-table border :data="data" style="width: 100%;" height="400" @selection-change="selectChange">
    <el-table-column type="selection" width="55"></el-table-column>
    <el-table-column prop="code" label="编码"></el-table-column>
    <el-table-column prop="name" label="名称"></el-table-column>
  </el-table>
</template>

<script lang="ts">
import { Component, Prop, Vue, Watch } from 'vue-property-decorator';
 
@Component
export default class HierarchyTable extends Vue {
  data: any[] = [];
 
  @Prop({ type: Array, required: true }) value!: any;
  @Prop({ type: Array }) skipCodes: any;
 
  @Watch('value')
  valueChanged(val) {
    this.updateData();
  }
 
  @Watch('skipCodes')
  skipCodesChanged() {
    this.updateData();
  }
 
  updateData() {
    this.data = this.skipCodes ? this.value.filter(it => !this.skipCodes.includes(it.code)) : this.value;
  }
 
  selectChange(selection) {
    this.$emit('selection-change', selection);
  }
}
</script>
 
<style scoped></style>

<p>Reversed message: "{{ reversedMessage() }}"</p>
<p>Reversed message: "{{ reversedMessage }}"</p>

// 计算属性
computed: {
  reversedMessage () {
    return this.message.split('').reverse().join('')
  }
}
// 方法
methods: {
  reversedMessage: function () {
    return this.message.split('').reverse().join('')
  }
}

computed: {
  now: function () {
    return Date.now()
  }
}

methods: {
  getAnswer: function () {
    this.answer = 'Thinking...'
    var vm = this
    axiOS.get('https://yesno.wtf/api')
      .then(function (response) {
        vm.answer = _.capitalize(response.data.answer)
      })
      .catch(function (error) {
        vm.answer = 'Error! Could not reach the API. ' + error
      })
  }
},
created: function () {
  // debounce 反弹函数
  this.debouncedGetAnswer = _.debounce(this.getAnswer, 500)
}

<template>
  <div>
    <child :user="user"></child>
    <label for="user">parent：</label>
    <input id="user" type="text" v-model="user.name">
  </div>
</template>
<script>
import Child from './child.vue'
export default {
  data () {
    return {
      user: { name: 'ligang' }
    }
  },
  components: { Child }
}
</script>

<template>
  <div>child: {{user}}</div>
</template>
<script>
export default {
  name: 'child',
  props: ['user']
}
</script>

<template>
  <div>
    <div>child:</div>
    <div>修改前：{{oldUser}} 修改后：{{user}}</div>
  </div>
</template>
<script>
export default {
  name: 'child',
  props: ['user'],
  data () {
    return {
      oldUser: {}
    }
  },
  watch: {
    user: {
      handler (val, oldVal) {
        this.oldUser = oldVal || val
      },
      deep: true,
      immediate: true
    }
  }
}
</script>

<template>
  <div>
    <div>child:</div>
    <div>修改前：{{oldUser}} 修改后：{{user}}</div>
  </div>
</template>
<script>
export default {
  name: 'child',
  props: ['user'],
  data () {
    return {
      oldUser: {}
    }
  },
  // 缓存 userInfo   
  computed: {
    userInfo () {
      return { ...this.user }
    }
  },
  watch: {
    userInfo: {
      handler (val, oldVal) {
        this.oldUser = oldVal || val
      },
      deep: true,
      immediate: true
    }
  }
}
</script>