4dkankan-components/docs/examples/tree/custom-node-class.vue

<template>
    <div class="custom-tree-node-container">
        <el-tree :data="data" show-checkbox node-key="id" default-expand-all :expand-on-click-node="false" :props="{ class: customNodeClass }" />
    </div>
</template>

<script lang="ts" setup>
import type Node from 'element-plus/es/components/tree/src/model/node'

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

const customNodeClass = (data: Tree, node: Node) => {
    if (data.isPenultimate) {
        return 'is-penultimate'
    }
    return null
}

const data: Tree[] = [
    {
        id: 1,
        label: 'Level one 1',
        children: [
            {
                id: 4,
                label: 'Level two 1-1',
                isPenultimate: true,
                children: [
                    {
                        id: 9,
                        label: 'Level three 1-1-1',
                    },
                    {
                        id: 10,
                        label: 'Level three 1-1-2',
                    },
                ],
            },
        ],
    },
    {
        id: 2,
        label: 'Level one 2',
        isPenultimate: true,
        children: [
            {
                id: 5,
                label: 'Level two 2-1',
            },
            {
                id: 6,
                label: 'Level two 2-2',
            },
        ],
    },
    {
        id: 3,
        label: 'Level one 3',
        isPenultimate: true,
        children: [
            {
                id: 7,
                label: 'Level two 3-1',
            },
            {
                id: 8,
                label: 'Level two 3-2',
            },
        ],
    },
]
</script>

<style>
.is-penultimate > .el-tree-node__content {
    color: #626aef;
}

.el-tree-node.is-expanded.is-penultimate > .el-tree-node__children {
    display: flex;
    flex-direction: row;
}
.is-penultimate > .el-tree-node__children > div {
    width: 25%;
}
</style>