Element UI框架中巧用树选择器的实现

<el-select
  v-model="dataArr"
  :multiple="multiple"
  filterable
  :placeholder="placeholder"
  :disabled="disabled"
  :collapse-tags="multiple"
  @remove-tag="handleTagChange"
  @visible-change="handleOptionHidden"
  class="hi-input">
  <el-option value="0"
    class="hidden">
  </el-option>
  <!--el-tree绑定的数组中children里的key值不能是0-->
  <el-tree
    ref="tree"
    :data="options"
    node-key="key"
    show-checkbox
    :default-checked-keys="selectedData"
    @check="handleCheckChange"
    :props="defaultProps">
  </el-tree>
</el-select>

handleCheckChange: function() {
  this.selectedData = this.$refs.tree.getCheckedKeys().filter(_ => _);
}

watch: {
  selectedData: function(newValue) {
    this.$nextTick(() => { this.dataArr = this.handleDataTransform(newValue, 'key', 'label'); });
  },
},
methods: {
  getNameById(array, value, id, name, multi) {
    let arr = array || [];
    let flag;
    let result = arr.filter(item => {
      return item[id] + '' === value + '';
    });
    if (multi) {
      flag = result.map(item => {
        return item[name];
      });
    } else {
      let obj = result[0];
      flag = name ? obj && obj[name] : obj;
    }
    return flag;
  },
  handleDataTransform: function(source, key, value) {
    return this.options.map(_ => {
      let arr = source.map(item => this.$util.getNameById(
        _.children,
        item,
        key,
        value
      )).filter(item => item);
      return arr;
    }).reduce((acc, cur) => {
      return acc.concat(cur);
    }, []);
  }
}

handleTagChange: function() {
  // handleDataTransform已经在之前定义过
  this.selectedData = this.handleDataTransform(this.dataArr, 'label', 'key');
  this.$refs.tree.setCheckedKeys(this.selectedData);
},

handleOptionHidden: function(item) {
  // 处理选中内容没变的情况
  if (item) {
    this.selectedItem = [...this.selectedData];
  } else {
    // this.$util.isEqual()是判断两个数组是否相等函数，网上很多，请自行谷歌
    if (!this.$util.isEqual(this.selectedItem, this.selectedData)) {
      this.handleUpdate(this.selectedData);
    }
  }
    },