树形下拉选择组件

***忘记摘抄那个博客的了,闲的时候记录了下;现在vue3版本的element-ui已经有类似的组件了
<!--
    /**
     * 树形下拉选择组件，下拉框展示树形结构，提供选择某节点功能，方便其他模块调用
     * 调用示例：
     * <tree-select 
     *  :height="400" // 下拉框中树形高度
     *  :width="200" // 下拉框中树形宽度
     *  size="small"  // 输入框的尺寸: medium/small/mini
     *  :data="data" // 树结构的数据
     *  :defaultProps="defaultProps" // 树结构的props
     *  multiple   // 多选
     *  clearable   // 可清空选择
     *  colkStrilapseTags   // 多选时将选中值按文字的形式展示
     *  checctly // 多选时，严格遵循父子不互相关联
     *  :nodeKey="nodeKey"   // 绑定nodeKey，默认绑定'id'
     *  :checkedKeys="defaultCheckedKeys"  // 传递默认选中的节点key组成的数组
     *   @popoverHide="popoverHide"> // 事件有两个参数：第一个是所有选中的节点ID，第二个是所有选中的节点数据
     * </tree-select>
     */
-->
<template>
  <div class="treeSelect">
    <div
      class="mask"
      v-show="isShowSelect"
      @click="isShowSelect = !isShowSelect"
    ></div>
    <el-popover
      placement="bottom-start"
      :width="width"
      trigger="manual"
      v-model="isShowSelect"
      @hide="popoverHide"
    >
      <el-tree
        class="common-tree"
        :style="style"
        ref="tree"
        :data="data"
        :props="defaultProps"
        :show-checkbox="multiple"
        :node-key="nodeKey"
        :check-strictly="checkStrictly"
        :default-expand-all="defaultexpandall"
        :expand-on-click-node="false"
        :check-on-click-node="multiple"
        :highlight-current="true"
        :auto-expand-parent="true"
        :default-expanded-keys="checkedKeys"
        @node-click="handleNodeClick"
        @check-change="handleCheckChange"
      ></el-tree>
      <el-select
        :style="selectStyle"
        slot="reference"
        ref="select"
        :size="size"
        v-model="selectedData"
        :multiple="multiple"
        :clearable="clearable"
        :collapse-tags="collapseTags"
        @click.native="isShowSelect = !isShowSelect"
        @remove-tag="removeSelectedNodes"
        @clear="removeSelectedNode"
        @change="changeSelectedNodes"
        @visible-change="changeIcon($event)"
        class="tree-select"
      >
        <el-option
          v-for="item in options"
          :key="item.value"
          :label="item.label"
          :value="item.value"
        ></el-option>
      </el-select>
    </el-popover>
  </div>
</template>
 
<script>
export default {
  name: "tree-select",
  props: {
    // 树结构数据
    data: {
      type: Array,
      default() {
        return [];
      },
    },
    defaultProps: {
      type: Object,
      default() {
        return {};
      },
    },
    // 是否展开
    defaultexpandall: {
      type: Boolean,
      default() {
        return true;
      },
    },
    // 配置是否可多选
    multiple: {
      type: Boolean,
      default() {
        return false;
      },
    },
    // 配置是否可清空选择
    clearable: {
      type: Boolean,
      default() {
        return true;
      },
    },
    // 配置多选时是否将选中值按文字的形式展示
    collapseTags: {
      type: Boolean,
      default() {
        return false;
      },
    },
    nodeKey: {
      type: String,
      default() {
        return "id";
      },
    },
    // 显示复选框情况下，是否严格遵循父子不互相关联
    checkStrictly: {
      type: Boolean,
      default() {
        return false;
      },
    },
    // 默认选中的节点key数组
    checkedKeys: {
      type: Array,
      default() {
        return [];
      },
    },
    size: {
      type: String,
      default() {
        return "small";
      },
    },
    width: {
      type: Number,
      default() {
        return 220;
      },
    },
    height: {
      type: Number,
      default() {
        return 260;
      },
    },
    // 单选情况下 展示所有父级名称
    single: {
      type: Boolean,
      default: false,
    },
  },
  data() {
    return {
      isShowSelect: false, // 是否显示树状选择器
      options: [],
      selectedData: [], // 选中的节点
      style: "height:" + this.height + "px;",
      selectStyle: "width:" + this.width + "px;",
      checkedIds: [],
      checkedData: [],
    };
  },
  mounted() {
    this.initCheckedData();
  },
  methods: {
    filterNode(value, data) {
      if (!value) return true;
      return data.label.indexOf(value) !== -1;
    },
    changeIcon(callBack) {
      this.$emit("changeIcon", callBack);
    },
    // 单选时点击tree节点，设置select选项
    setSelectOption(node) {
      // 多个层级 拼接
      let nav_title1 = "",
        nav_title2 = "",
        nav_title3 = "",
        nav_title4 = "";
      switch (node.level) {
        case 1:
          nav_title1 = node.data.roomName;
          nav_title2 = "";
          nav_title3 = "";
          nav_title4 = "";
          break;
        case 2:
          nav_title1 = node.parent.data.roomName + " - ";
          nav_title2 = node.data.roomName;
          nav_title3 = "";
          nav_title4 = "";
          break;
        case 3:
          nav_title1 = node.parent.parent.data.roomName + " - ";
          nav_title2 = node.parent.data.roomName + " - ";
          nav_title3 = node.data.roomName;
          nav_title4 = "";
          break;
        case 4:
          nav_title1 = node.parent.parent.parent.data.roomName + " - ";
          nav_title2 = node.parent.parent.data.roomName + " - ";
          nav_title3 = node.parent.data.roomName + " - ";
          nav_title4 = node.data.roomName;
          break;
        default:
          break;
      }
      let value = nav_title1 + nav_title2 + nav_title3 + nav_title4;

      let tmpMap = {};
      tmpMap.value = node.key;
      tmpMap.label = node.label;
      this.options = [];
      if (this.single) {
        tmpMap.label = value;
      }
      this.options.push(tmpMap);
      this.selectedData = node.key;
    },
    // 单选，选中传进来的节点
    checkSelectedNode(checkedKeys) {
      var item = checkedKeys[0];
      this.$refs.tree.setCurrentKey(item);
      var node = this.$refs.tree.getNode(item);
      this.setSelectOption(node);
      if (this.checkedKeys.length != 0) {
        this.$emit("change", node);
      }
    },
    // 多选，勾选上传进来的节点
    checkSelectedNodes(checkedKeys) {
      this.$refs.tree.setCheckedKeys(checkedKeys);
    },
    // 单选，清空选中
    clearSelectedNode() {
      this.selectedData = "";
      this.$refs.tree.setCurrentKey(null);
    },
    // 多选，清空所有勾选
    clearSelectedNodes() {
      var checkedKeys = this.$refs.tree.getCheckedKeys(); // 所有被选中的节点的 key 所组成的数组数据
      for (let i = 0; i < checkedKeys.length; i++) {
        this.$refs.tree.setChecked(checkedKeys[i], false);
      }
    },
    initCheckedData() {
      if (this.multiple) {
        // 多选
        if (this.checkedKeys.length > 0) {
          this.checkSelectedNodes(this.checkedKeys);
        } else {
          this.clearSelectedNodes();
        }
      } else {
        // 单选
        if (this.checkedKeys.length > 0) {
          this.checkSelectedNode(this.checkedKeys);
        } else {
          this.clearSelectedNode();
        }
      }
    },
    popoverHide() {
      if (this.multiple) {
        this.checkedIds = this.$refs.tree.getCheckedKeys(); // 所有被选中的节点的 key 所组成的数组数据
        this.checkedData = this.$refs.tree.getCheckedNodes(); // 所有被选中的节点所组成的数组数据
      } else {
        this.checkedIds = this.$refs.tree.getCurrentKey();
        this.checkedData = this.$refs.tree.getCurrentNode();
      }
      this.$emit("popoverHide", this.checkedIds, this.checkedData);
    },
    // 单选，节点被点击时的回调,返回被点击的节点数据
    handleNodeClick(data, node) {
      if (!this.multiple) {
        this.setSelectOption(node);
        this.isShowSelect = !this.isShowSelect;
        this.$emit("change", node);
      }
    },
    // 多选，节点勾选状态发生变化时的回调
    handleCheckChange() {
      var checkedKeys1 = this.$refs.tree.getCheckedKeys(); // 所有被选中的节点的 key 所组成的数组数据
      // ************ 二次修改,修复了全选报错问题********************
      var checkedKeys = [];
      checkedKeys1.map((ele, index) => {
        if (ele != undefined) {
          checkedKeys.push(ele);
        }
      });
      //  ***********************************
      this.options = checkedKeys.map((item) => {
        var node = this.$refs.tree.getNode(item); // 所有被选中的节点对应的node
        let tmpMap = {};
        // 过滤掉 父级
        if (node.childNodes.length == 0) {
          tmpMap.value = node.key;
          tmpMap.label = node.label;
          tmpMap.disabled = node.disabled;
          tmpMap.childNodes = node.childNodes;
        }
        return tmpMap;
      });

      // if (this.options.length > 10) {
      //   return false;
      // }
      this.selectedData = this.options.map((item) => {
        return item.value;
      });
      let arr_Data = this.selectedData.filter((item) => item);
      this.$emit("change", arr_Data);
    },
    // 多选,删除任一select选项的回调
    removeSelectedNodes(val) {
      this.$refs.tree.setChecked(val, false);
      var node = this.$refs.tree.getNode(val);
      if (!this.checkStrictly && node.childNodes.length > 0) {
        this.treeToList(node).map((item) => {
          if (item.childNodes.length <= 0) {
            this.$refs.tree.setChecked(item, false);
          }
        });
        this.handleCheckChange();
      }
      let arr_Data = this.selectedData.filter((item) => item);

      this.$emit("change", arr_Data);
    },
    treeToList(tree) {
      var queen = [];
      var out = [];
      queen = queen.concat(tree);
      while (queen.length) {
        var first = queen.shift();
        if (first.childNodes) {
          queen = queen.concat(first.childNodes);
        }
        out.push(first);
      }
      return out;
    },
    // 单选,清空select输入框的回调
    removeSelectedNode() {
      this.clearSelectedNode();
      this.$emit("change", this.selectedData);
    },
    // 选中的select选项改变的回调
    changeSelectedNodes(selectedData) {
      // 多选,清空select输入框时，清除树勾选
      if (this.multiple && selectedData.length <= 0) {
        this.clearSelectedNodes();
      }
      console.log(this.selectedData);
      this.$emit("change", this.selectedData);
    },
  },
  watch: {
    isShowSelect() {
      // 隐藏select自带的下拉框
      this.$refs.select.blur();
    },
    checkedKeys(val) {
      if (!val) return;
      this.checkedKeys = val;
      this.initCheckedData();
    },
  },
};
</script>
 
<style lang="scss" scoped>
.mask {
  width: 100%;
  height: 100%;
  position: fixed;
  top: 0;
  left: 0;
  opacity: 0;
  z-index: 11;
}
.common-tree {
  overflow: auto;
}
.tree-select {
  z-index: 111;
}
</style>