4dkankan-components/docs/examples/tree-v2/default-state.vue

<template>
    <el-tree-v2 :data="data" :height="208" :props="props" show-checkbox :default-checked-keys="defaultCheckedKeys" :default-expanded-keys="defaultExpandedKeys" />
</template>
<script lang="ts" setup>
import { ref } from 'vue'

interface Tree {
    id: string
    label: string
    children?: Tree[]
}

const getKey = (prefix: string, id: number) => {
    return `${prefix}-${id}`
}

const createData = (maxDeep: number, maxChildren: number, minNodesNumber: number, deep = 1, key = 'node'): Tree[] => {
    let id = 0
    return Array.from({ length: minNodesNumber })
        .fill(deep)
        .map(() => {
            const childrenNumber = deep === maxDeep ? 0 : Math.round(Math.random() * maxChildren)
            const nodeKey = getKey(key, ++id)
            return {
                id: nodeKey,
                label: nodeKey,
                children: childrenNumber ? createData(maxDeep, maxChildren, childrenNumber, deep + 1, nodeKey) : undefined,
            }
        })
}

const props = {
    value: 'id',
    label: 'label',
    children: 'children',
}
const data = createData(4, 30, 40)
const checkedKeys: string[] = []
const expanedKeys: string[] = []
for (const datum of data) {
    const children = datum.children
    if (children) {
        expanedKeys.push(datum.id)
        checkedKeys.push(children[0].id)
        break
    }
}

const defaultCheckedKeys = ref(checkedKeys)
const defaultExpandedKeys = ref(expanedKeys)
</script>