谷粒商城学习日记（28）——三级分类拖拽修改、批量修改、删除

拖拽修改（页面效果）

页面效果

首先设置el-tree的属性

:draggable=“draggable”
可拖拽效果绑定变量

:allow-drop=“allowDrop”
是否可以拖拽后放置定义方法绑定

@node-drop=“handleDrop”
拖拽放置后调用方法

ref=“menuTree”
绑定tree组件获取checkbox选中元素

 <el-tree
      :data="menus"
      node-key="catId"
      :props="defaultProps"
      @node-click="handleNodeClick"
       show-checkbox
      :expand-on-click-node="false"
      :draggable="draggable"
      :allow-drop="allowDrop"
      @node-drop="handleDrop"
       ref="menuTree"
      :default-expanded-keys="expandedKey"
    >

数据收集

在data中绑定数据

 data() {
    //这里存放数据
    return {
      pCid: [],
      draggable: true,
      updateNodes: [],
      maxLevel: 0,
      dialogVisible: false, //弹框不显示
      dialogType: "",
      title: "",
      category: {
        catId: null,
        name: "",
        parentcid: 0,
        catLevel: 0,
        showStatus: 1,
        sort: 0,
        icon: "",
        productunit: "",
        productCount: 0,
      },
      menus: [],
      expandedKey: [],
      defaultProps: {
        children: "child",
        label: "name",
      },
    };
  },

写好数据收集方法

//是否可以被拖拽后放置
    allowDrop(draggingNode, dropNode, type) {
      //1、被拖动的当前节点以及所在的父节点总层数不能大于3

      //1）、被拖动的当前节点总层数
      console.log("allowDrop:", draggingNode, dropNode, type);
      //
      this.countNodeLevel(draggingNode);
      //当前正在拖动的节点+父节点所在的深度不大于3即可
      let deep = Math.abs(this.maxLevel - draggingNode.level) + 1;
      console.log("深度：", deep);

      //   this.maxLevel
      if (type == "inner") {
        // console.log(
        //   `this.maxLevel：${this.maxLevel}；draggingNode.data.catLevel：${draggingNode.data.catLevel}；dropNode.level：${dropNode.level}`
        // );
        return deep + dropNode.level <= 3;
      } else {
        return deep + dropNode.parent.level <= 3;
      }
    },
    //拖拽后调用方法
    handleDrop(draggingNode, dropNode, dropType, ev) {
      console.log("handleDrop: ", draggingNode, dropNode, dropType);
      //1、当前节点最新的父节点id
      let pCid = 0;
      let siblings = null;
      if (dropType == "before" || dropType == "after") {
        pCid =
          dropNode.parent.data.catId == undefined
            ? 0
            : dropNode.parent.data.catId;
        siblings = dropNode.parent.childNodes;
      } else {
        pCid = dropNode.data.catId;
        siblings = dropNode.childNodes;
      }
      this.pCid.push(pCid);

      //2、当前拖拽节点的最新顺序，
      for (let i = 0; i < siblings.length; i++) {
        if (siblings[i].data.catId == draggingNode.data.catId) {
          //如果遍历的是当前正在拖拽的节点
          let catLevel = draggingNode.level;
          if (siblings[i].level != draggingNode.level) {
            //当前节点的层级发生变化
            catLevel = siblings[i].level;
            //修改他子节点的层级
            this.updateChildNodeLevel(siblings[i]);
          }
          this.updateNodes.push({
            catId: siblings[i].data.catId,
            sort: i,
            parentCid: pCid,
            catLevel: catLevel,
          });
        } else {
          this.updateNodes.push({ catId: siblings[i].data.catId, sort: i });
        }
      }

      //3、当前拖拽节点的最新层级
      console.log("updateNodes", this.updateNodes);
    },
    // 递归调用修改子节点层级
    updateChildNodeLevel(node) {
      if (node.childNodes.length > 0) {
        for (let i = 0; i < node.childNodes.length; i++) {
          var cNode = node.childNodes[i].data;
          this.updateNodes.push({
            catId: cNode.catId,
            catLevel: node.childNodes[i].level
          });
          this.updateChildNodeLevel(node.childNodes[i]);
        }
      }
    },
    //递归查询当前拖拽节点的层级
    countNodeLevel(node) {
      //找到所有子节点，求出最大深度
      if (node.childNodes != null && node.childNodes.length > 0) {
        for (let i = 0; i < node.childNodes.length; i++) {
          if (node.childNodes[i].level > this.maxLevel) {
            this.maxLevel = node.childNodes[i].level;
          }
          this.countNodeLevel(node.childNodes[i]);
        }
      }
    },

批量修改（数据交互）

前面已经实现了拖动的页面效果，现在批量修改需要将可拖拽效果绑定到switch开关上

修改数据datas属性

 draggable: false,

添加switch组件和批量修改按钮

<template>
  <div>
    <el-switch v-model="draggable" active-text="开启拖拽" inactive-text="关闭拖拽"></el-switch>
    <el-button v-if="draggable" @click="batchSave">批量保存</el-button>

前端数据传输

添加保存方法

 batchSave() {
    this.$http({
      url: this.$http.adornUrl("/product/category/update/sort"),
      method: "post",
      data: this.$http.adornData(this.updateNodes, false),
    }).then(({ data }) => {
      this.$message({
        message: "菜单顺序等修改成功",
        type: "success",
      });
      //刷新出新的菜单
      this.getMenus();
      //设置需要默认展开的菜单
      this.expandedKey = this.pCid;
      this.updateNodes = [];
      this.maxLevel = 0;
      // this.pCid = 0;
    });
  },

后台代码修改

这里前端传过来的是一个json对象数组
我们在product里面编写一个批量修改方法
categoryController.java

/**
     * 修改
     */
    @RequestMapping("/update/sort")
    public R updateSort(@RequestBody List<CategoryEntity> updateNodes){
        categoryService.updateBatchById(updateNodes);
        return R.ok();
    }

批量删除

页面加上批量删除按钮

<el-button type="danger" @click="batchDelete">批量删除</el-button>

调用方法

batchDelete() {
      let catIds = [];
      let checkedNodes = this.$refs.menuTree.getCheckedNodes();
      console.log("被选中的元素", checkedNodes);
      for (let i = 0; i < checkedNodes.length; i++) {
        catIds.push(checkedNodes[i].catId);
      }
      this.$confirm(`是否批量删除【${catIds}】菜单?`, "提示", {
        confirmButtonText: "确定",
        cancelButtonText: "取消",
        type: "warning"
      })
        .then(() => {
          this.$http({
            url: this.$http.adornUrl("/product/category/delete"),
            method: "post",
            data: this.$http.adornData(catIds, false)
          }).then(({data}) => {
            this.$message({
              message: "菜单批量删除成功",
              type: "success"
            });
            this.getDataList();
          });
        })
        .catch(() => {
        });
    },