Element@2.15.14-tree checkStrictly 状态实现父项联动子项，实现节点自定义编辑、新增、删除功能

背景：现在有一个新需求，需要借助树结构来实现词库的分类管理，树的节点是不同的分类，不同的分类可以有自己的词库，所以父子节点是互不影响的；同样为了选择的方便性，提出了新需求，选择了父级子级需要全选，父级取消勾选子级需要全部取消勾选；分类支持修改名称、增加子节点、删除子节点，多选子节点时需要获取当前所选分类下的所有词库。

一、开发前需要知道的

1、树结构需要借助 element 的 tree 组件

2、树结构需要设置父子级不关联，即 :check-strictly="true"

3、节点选择时如果是非叶子结点（最后一层的子节点，没有 children），需要递归获取子节点，如果进行节点的选择与取消选择

4、自定义节点需要通过 slot 方式活着 render-content 方式实现

二、实现流程

1、引入 tree，传入源数据 data、设置 key，设置默认配置属性 defaultProps

1. 定义 tree
<el-tree:check-strictly="true":data="data"@check-change="checkChange"ref="treeRef"show-checkboxdefault-expand-allnode-key="id"ref="tree"highlight-current:props="defaultProps"
>
</el-tree>
2. 设置 data
data = [{id: xx, label: xx, children: {id: number, label: string, children: []}[]}]
3. 设置父子不关联
:check-strictly="true"
4. 设置默认配置
const defaultProps = {children: "children",label: "label",
}

2、实现父子勾选子级联动

// 1. 给 el-tree 绑定 check-change 事情
@check-change="checkChange"// 2. 实现 checkChange 函数
// data：当前节点 checked：节点是否选中 indeterminate：是否有选中的子项
function checkChange(data, checked, indeterminate) {console.log("data, checked, indeterminate", data, checked, indeterminate);this.$nextTick(() => {// 2.1 获取节点详细信息const nodeInfo = this.$refs.treeRef.getNode(data.id);const { isLeaf, checked } = nodeInfo;this.nodeInfo = nodeInfo;function getAllIds(arr, res = []) {for (let i = 0; i < arr.length; i++) {res.push(arr[i].id);if (arr[i].children && arr[i].children.length) {getAllIds(arr[i].children, res);}}return res;}// 2.2 获取当前已选中的节点console.log(this.$refs.treeRef.getCheckedKeys());// 2.3 如果是父级，子级选中跟取消选择if (!isLeaf) {const checkedIds = this.$refs.treeRef.getCheckedKeys();const ids = getAllIds(nodeInfo.data.children);console.log(ids);// 2.3.1 父级选中，子级全选if (checked) {this.$refs.treeRef.setCheckedKeys(Array.from(new Set([...checkedIds, ...ids])));} else {// 2.3.2 父级取消选中，子级全不选this.$refs.treeRef.setCheckedKeys(Array.from(new Set(checkedIds.filter((item) => !ids.includes(item)))));}}});
},

3、通过 slot 实现编辑、新增、删除

1. slot 内容
<span class="custom-tree-node" slot-scope="{ node, data }"><span>{{ node.label }}</span><span><el-button type="text" size="mini" @click="() => edit(node, data)">edit</el-button><el-button type="text" size="mini" @click="() => append(data)">Append</el-button><el-buttontype="text"size="mini"@click="() => remove(node, data)">Delete</el-button></span>
</span>2. 设置函数
{// 2.1 编辑，子级可以弹窗回显名称，然后修改名称edit(node, data) {console.log(node, data);},// 2.2 新增，新增内容自己定，也可以弹窗自定义名称，通过接口返回 id 再拼接append(data) {const newChild = { id: this.id++, label: "testtest", children: [] };if (!data.children) {this.$set(data, "children", []);}data.children.push(newChild);},// 2.3 删除，可以先进行提示，提示确定后再删remove(node, data) {const parent = node.parent;const children = parent.data.children || parent.data;const index = children.findIndex((d) => d.id === data.id);children.splice(index, 1);}
}

三、整体代码

<!DOCTYPE html>
<html lang="en"><head><meta charset="UTF-8" /><meta name="viewport" content="width=device-width, initial-scale=1.0" /><title>Document</title><linkrel="stylesheet"href="https://unpkg.com/element-ui@2.15.14/lib/theme-chalk/index.css"/><style>.custom-tree-node {flex: 1;display: flex;align-items: center;justify-content: space-between;font-size: 14px;padding-right: 8px;}</style></head><body><script src="https://unpkg.com/vue@2.7.16/dist/vue.js"></script><script src="https://unpkg.com/element-ui@2.15.14/lib/index.js"></script><div id="app"><el-tree:check-strictly="true":data="data"@check-change="checkChange"ref="treeRef"show-checkboxdefault-expand-allnode-key="id"ref="tree"highlight-current:props="defaultProps"><span class="custom-tree-node" slot-scope="{ node, data }"><span>{{ node.label }}</span><span><el-button type="text" size="mini" @click="() => edit(node, data)">edit</el-button><el-button type="text" size="mini" @click="() => append(data)">Append</el-button><el-buttontype="text"size="mini"@click="() => remove(node, data)">Delete</el-button></span></span></el-tree><div class="buttons"><el-button @click="getCheckedNodes">通过 node 获取</el-button><el-button @click="getCheckedKeys">通过 key 获取</el-button><el-button @click="setCheckedNodes">通过 node 设置</el-button><el-button @click="setCheckedKeys">通过 key 设置</el-button><el-button @click="resetChecked">清空</el-button></div></div><script>var Main = {methods: {edit(node, data) {console.log(node, data);},append(data) {const newChild = { id: this.id++, label: "testtest", children: [] };if (!data.children) {this.$set(data, "children", []);}data.children.push(newChild);},remove(node, data) {const parent = node.parent;const children = parent.data.children || parent.data;const index = children.findIndex((d) => d.id === data.id);children.splice(index, 1);},checkChange(data, checked, indeterminate) {this.node = data;this.checked = checked;this.indeterminate = indeterminate;// console.log("data, checked, indeterminate", data, checked, indeterminate);this.$nextTick(() => {console.log(data.id);const nodeInfo = this.$refs.treeRef.getNode(data.id);const { isLeaf, checked } = nodeInfo;this.nodeInfo = nodeInfo;console.log(nodeInfo);// console.log(//   "nodeInfo, isLeaf, childNodes, checked",//   nodeInfo,//   isLeaf,//   childNodes,//   checked// );function getAllIds(arr, res = []) {for (let i = 0; i < arr.length; i++) {res.push(arr[i].id);if (arr[i].children && arr[i].children.length) {getAllIds(arr[i].children, res);}}return res;}console.log(this.$refs.treeRef.getCheckedKeys());if (!isLeaf) {const checkedIds = this.$refs.treeRef.getCheckedKeys();const ids = getAllIds(nodeInfo.data.children);console.log(ids);if (checked) {this.$refs.treeRef.setCheckedKeys(Array.from(new Set([...checkedIds, ...ids])));} else {this.$refs.treeRef.setCheckedKeys(Array.from(new Set(checkedIds.filter((item) => !ids.includes(item)))));}}});},getCheckedNodes() {console.log(this.$refs.tree.getCheckedNodes());},getCheckedKeys() {console.log(this.$refs.tree.getCheckedKeys());},setCheckedNodes() {this.$refs.tree.setCheckedNodes([{id: 5,label: "二级 2-1",},{id: 9,label: "三级 1-1-1",},]);},setCheckedKeys() {this.$refs.tree.setCheckedKeys([3]);},resetChecked() {this.$refs.tree.setCheckedKeys([]);},},data() {return {id: 10,data: [{id: 1,label: "一级 1",children: [{id: 4,label: "二级 1-1",children: [{id: 9,label: "三级 1-1-1",},{id: 10,label: "三级 1-1-2",},],},],},{id: 2,label: "一级 2",children: [{id: 5,label: "二级 2-1",},{id: 6,label: "二级 2-2",},],},{id: 3,label: "一级 3",children: [{id: 7,label: "二级 3-1",},{id: 8,label: "二级 3-2",},],},],defaultProps: {children: "children",label: "label",},};},};var Ctor = Vue.extend(Main);new Ctor().$mount("#app");</script></body>
</html>