SpringBoot+Vue+ElementUI： Tree形数据增删改查及拖拽

比眉伴天荒 2022-12-24 11:56 213阅读 0赞

数据查询可以查看[《SpringBoot：查询Tree形数据》][SpringBoot_Tree]，这里不另外展开，主要讲拖拽的逻辑。

数据库存储结构如下：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2x0MzI2MDMwNDM0_size_16_color_FFFFFF_t_70]

*  project\_id、create\_time、update\_time是业务逻辑字段(查询条件)，可忽略。

#### SpringBoot ####

*  MODEL

public class TestCaseNodeDO { 
    
        /** * 节点id */
        @TableId(value = "id", type = IdType.AUTO)
        private Integer id;
    
        /** * 项目id */
        private Integer projectId;
    
        /** * 节点名称 */
        private String name;
    
        /** * 父节点id */
        private Integer parentId;
    
        /** * 节点层级 */
        private Integer level;
    
        /** * 创建时间 */
        @JsonFormat(locale="zh", timezone="GMT+8", pattern="yyyy-MM-dd HH:mm:ss")
        private Date createTime;
    
        /** * 更新时间 */
        @JsonFormat(locale="zh", timezone="GMT+8", pattern="yyyy-MM-dd HH:mm:ss")
        private Date updateTime;
    
        /** * 排序 */
        private Integer pos;
        
    }

public class TreeBO { 
 
 private Integer id;
 
 private String name;
 
 private Integer level;
 
 private Integer pos;
 
 private List<TreeBO> children;
 }

*  Controller  
    提供两个接口，一个是节点的拖拽`/drag`，一个是拖拽后节点的排序`/position`

@PostMapping("/create")
 public CreatedVO create(@RequestBody TestCaseNodeDO testCaseNodeDO) { 
 testCaseNodeService.addNode(testCaseNodeDO);
 return new CreatedVO();
 }
 
 // 这里的ids代表要删除的节点id于其所有子节点id
 @PostMapping("/delete")
 public DeletedVO delete(@RequestBody List<Integer> ids) { 
 testCaseNodeService.deleteNodes(ids);
 return new DeletedVO();
 }
 
 @PostMapping("/drag")
 public UpdatedVO drag(@RequestBody TreeBO treeBO) { 
 testCaseNodeService.nodeDrag(treeBO);
 return new UpdatedVO();
 }
 
 @PostMapping("/position")
 public UpdatedVO position(@RequestBody List<Integer> ids) { 
 testCaseNodeService.nodePosition(ids);
 return new UpdatedVO();
 }

*  service  
    拖拽节点，并遍历子节点（所有子节点只修改了level），所有数据库操作使用了`mybatis-plus`，语法进自行百度

public void nodeDrag(TreeBO nodeTree) { 
 
 List<TestCaseNodeDO> updateNodes = new ArrayList<>();
 buildUpdateTestCase(nodeTree, updateNodes, 0, 1);
 
 updateNodes.forEach( node -> { 
 testCaseNodeMapper.updateById(node);
 });
 }
 
 private void buildUpdateTestCase(TreeBO rootNode, List<TestCaseNodeDO> updateNodes, Integer parentId, int level) { 
 
 TestCaseNodeDO testCaseNode = new TestCaseNodeDO();
 testCaseNode.setId(rootNode.getId());
 testCaseNode.setLevel(level);
 testCaseNode.setParentId(parentId);
 testCaseNode.setPos(rootNode.getPos());
 updateNodes.add(testCaseNode);
 
 List<TreeBO> children = rootNode.getChildren();
 if (children != null && children.size() > 0) { 
 for (TreeBO child : children) { 
 buildUpdateTestCase(child, updateNodes, rootNode.getId(), level + 1);
 }
 }
 }

设置节点pos：获取相邻节点，然后将该节点pos设置为相邻两节点的中间值

public boolean nodePosition(List<Integer> ids) { 
 // 获取相邻节点 id
 Integer before = ids.get(0);
 Integer current = ids.get(1);
 Integer after = ids.get(2);
 
 TestCaseNodeDO beforeCase = null;
 TestCaseNodeDO afterCase = null;
 
 TestCaseNodeDO currentNode = getCaseNode(current);
 // 获取相邻节点
 if (before != 0) { 
 beforeCase = getCaseNode(before);
 beforeCase = beforeCase.getLevel().equals(currentNode.getLevel()) ? beforeCase : null;
 }
 
 if (after != 0) { 
 afterCase = getCaseNode(after);
 afterCase = afterCase.getLevel().equals(currentNode.getLevel()) ? afterCase : null;
 }
 
 int pos;
 
 if (beforeCase == null) { 
 pos = afterCase != null ? afterCase.getPos() / 2 : 1024;
 } else { 
 pos = afterCase != null ? (beforeCase.getPos() + afterCase.getPos()) / 2 : beforeCase.getPos() + 1024;
 }
 currentNode.setPos(pos);
 return testCaseNodeMapper.updateById(currentNode) > 0;
 }
 
 // 通过节点id获取节点
 private TestCaseNodeDO getCaseNode(Integer id) { 
 return testCaseNodeMapper.selectById(id);
 }

随便补充一下**添加节点**的逻辑，方便理解`pos`字段定义逻辑。在添加节点时，如果在同一父节点下已经存在同级节点，则获取所有节点中pos最大的值，再+1024，否则直接设为1024

public boolean addNode(TestCaseNodeDO node) { 
 node.setCreateTime(new Date());
 node.setUpdateTime(new Date());
 Integer pos = getNextLevelPos(node.getProjectId(), node.getLevel(), node.getParentId());
 node.setPos(pos);
 return testCaseNodeMapper.insert(node) > 0;
 }
 
 /** * 获得同级模块下一个 pos 值 * @param projectId project id * @param level node level * @param parentId node parent id * @return 同级模块下一个 pos 值 */
 private Integer getNextLevelPos(Integer projectId, Integer level, Integer parentId) { 
 List<TestCaseNodeDO> list = new LambdaQueryChainWrapper<>(testCaseNodeMapper)
 .eq(TestCaseNodeDO::getProjectId, projectId)
 .eq(TestCaseNodeDO::getLevel, level)
 .eq(parentId != null, TestCaseNodeDO::getParentId, parentId)
 .orderByDesc(TestCaseNodeDO::getPos)
 .list();
 if (!CollectionUtils.isEmpty(list)) { 
 return list.get(0).getPos() + 1024;
 } else { 
 return 1024;
 }
 }

删除比较简单

public boolean deleteNodes(List<Integer> ids) { 
 return testCaseNodeMapper.deleteBatchIds(ids) > 0;
 }

#### Vue ####

![在这里插入图片描述][20201128105117137.png]  
前端展示效果如图所示：每个节点鼠标停留时，会出现编辑、添加和删除的按钮

<el-tree class="filter-tree node-tree" :data="treeNodes" :default-expanded-keys="expandedNode" node-key="id" @node-drag-end="handleDragEnd" @node-expand="nodeExpand" @node-collapse="nodeCollapse" :filter-node-method="filterNode" :expand-on-click-node="false" highlight-current :draggable="draggable" :props="defaultProps" ref="tree">
 <template v-slot:default="{node,data}">
 
 
 
 
 		
 {
 { node.label }}
 
 
 <el-tooltip class="item" effect="dark" :open-delay="200" content="重命名" placement="top">
 
 </el-tooltip>
 <el-tooltip class="item" effect="dark" :open-delay="200" content="添加子模块" placement="top">
 
 </el-tooltip>
 <el-tooltip class="item" effect="dark" :open-delay="200" content="删除" placement="top">
 
 </el-tooltip>
 
 
 </template>
 </el-tree>

因为是封装过的tree，有一些不需要的元素或字段大家可自行删除，icon的@click事件请自行添加

async handleDragEnd(draggingNode, dropNode, dropType) { 
 if (dropType === 'none' || dropType === undefined) { 
 return
 }
 const param = this.buildParam(draggingNode, dropNode, dropType)
 
 this.list = []
 this.getNodeTree(this.treeNodes, draggingNode.data.id, this.list)
 // 这里进行drag的接口请求，如果拖拽成功，再调用position接口
 const res = await Node.dragNode(param)
 if (res.code < window.MAX_SUCCESS_CODE) { 
 await Node.nodePosition(this.list)
 ...
 } else { 
 ...
 }
 },
 buildParam(draggingNode, dropNode, dropType) { 
 let param
 if (dropNode.level === 1 && dropType !== 'inner') { 
 param = draggingNode.data
 } else { 
 this.treeNodes.some(node => { 
 param = this.findTreeByNodeId(node, dropNode.data.id)
 return param
 })
 }
 return param
 },
 findTreeByNodeId(rootNode, nodeId) { 
 if (rootNode.id === nodeId) { 
 return rootNode
 }
 if (rootNode.children) { 
 for (let i = 0; i < rootNode.children.length; i++) { 
 if (this.findTreeByNodeId(rootNode.children[i], nodeId)) { 
 return rootNode
 }
 }
 }
 },
 getNodeTree(nodes, id, list) { 
 if (!nodes) { 
 return
 }
 for (let i = 0; i < nodes.length; i++) { 
 if (nodes[i].id === id) { 
 list[0] = i - 1 >= 0 ? nodes[i - 1].id : 0
 list[1] = nodes[i].id
 list[2] = i + 1 < nodes.length ? nodes[i + 1].id : 0
 return
 }
 if (nodes[i].children) { 
 this.getNodeTree(nodes[i].children, id, list)
 }
 }
 },
 // 这里点击删除按钮时会调用remove弹出弹出层，二次确认删除才会调用confirmRemove进行删除
 remove(node) { 
 const nodeIds = []
 this.getChildNodeId(node.data, nodeIds)
 this.removeNodeIds = nodeIds
 this.confirmDeleteDialog = true
 },
 async confirmRemove() { 
 const res = await Node.deleteNodes(this.removeNodeIds)
 if (res.code < window.MAX_SUCCESS_CODE) { 
 ...
 } else { 
 ...
 }
 },
 getChildNodeId(rootNode, nodeIds) { 
 // 递归获取所有子节点ID
 nodeIds.push(rootNode.id)
 if (rootNode.children) { 
 for (let i = 0; i < rootNode.children.length; i++) { 
 this.getChildNodeId(rootNode.children[i], nodeIds)
 }
 }
 },

补上css

.custom-tree-node { 
      flex: 11 auto;
      display: flex;
      align-items: center;
      justify-content: space-between;
      font-size: 14px;
      padding-right: 8px;
      width: 100%;
    }
    
    .node-tree { 
      margin-top: 15px;
    }
    
    .father .child { 
      display: none;
    }
    
    .father:hover .child { 
      display: block;
    }
    
    .node-title { 
      width: 0;
      text-overflow: ellipsis;
      white-space: nowrap;
      flex: 1 1 auto;
      padding: 0 5px;
      overflow: hidden;
    }
    
    .node-operate > i { 
      color: #409eff;
      margin: 0 5px;
    }

到这里大概功能就已经OK了，写文章时删除了部分我觉得不需要po出的代码，如有遗漏请在文章下方留言，我会再不断更新文章内容~

[SpringBoot_Tree]: https://jiandansuifeng.blog.csdn.net/article/details/110038032
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2x0MzI2MDMwNDM0_size_16_color_FFFFFF_t_70]: /images/20221120/ced5f3b6b5ff423ab84f8d93eb49517e.png
[20201128105117137.png]: /images/20221120/9608b61072834e2e85671b9017af8207.png