Tree

A lightweight JavaScript library for tree data structure operations.

Installation

npm i @axolo/tree

Usage

import Tree from '@axolo/tree'

// Sample data
const array = [
  { id: 1, parentId: null, name: 'Root' },
  { id: 2, parentId: 1, name: 'Child 1' },
  { id: 3, parentId: 1, name: 'Child 2' },
  { id: 4, parentId: 2, name: 'Grandchild' }
]

// Convert array to Tree instance
// tree.value is tree structure data
const tree = Tree.from(array)

// Convert tree to array
const resultArray = tree.toArray()

// Get path by id
const path = tree.path(4) // [{ id: 1, ... }, { id: 2, ... }, { id: 4, ... }]
const pathIds = tree.path(4, 'id') // [1, 2, 4]
const pathIndices = tree.path(4, null) // [0, 0, 0]

// Get parent node by id
const parent = tree.parent(4) // { id: 2, ... }

// Get myself node by id
const myself = tree.myself(4) // { id: 4, ... }

// Filter tree with condition function
const filtered = tree.filter(node => node.name.includes('Child'))

// Get subtree by id
const subtree = tree.sub(2) // [{ id: 2, children: [...] }]

// Get tree depth
const depth = tree.getDepth() // 3

Configuration

| Property | Type | Default | Description | | -------- | ------ | ---------- | ------------------------------------ | | id | string | 'id' | Unique identifier property name | | parentId | string | 'parentId' | Parent node identifier property name | | children | string | 'children' | Children property name | | depth | string | 'depth' | Depth property name | | leaf | string | 'leaf' | Leaf node flag property name |

API

Tree.from(array, config = {})

Convert an array to a Tree instance.

Param:

• array {Array} - Flattened tree data array
• config {Object} - Optional configuration

Return: {Tree} - Tree instance

new Tree(tree, config = {})

Create a new Tree instance.

Param:

• tree {Array} - Tree structure data array
• config {Object} - Optional configuration

Return: {Tree} - Tree instance

tree.toArray()

Convert tree back to flattened array.

Return: {Array} - Flattened tree array

tree.path(id, key = undefined)

Get the path from root to target node.

Param:

• id {String|Number} - Target node ID
• key {String|null|undefined} - Property key to return

Return: {Array} - Path array containing nodes, specified keys, or indices

• key exists: Return keys like [root[key], ..., parent[key], self[key]]
• key is null: Return indices like [root.index, ..., parent.index, self.index]
• key is undefined: Return nodes like [root, ..., parent, self]

tree.parent(id)

Get the parent node of the target node.

Param:

• id {String|Number} - Target node ID

Return: {Object|null} - Parent node or null

tree.myself(id)

Get the myself node of the target node.

Param:

• id {String|Number} - Target node ID

Return: {Object|null} - Myself node or null

tree.filter(condition)

Filter tree nodes by condition.

Param:

• condition {Function} - Filter function (receives node, return boolean)

Return: {Tree} - Tree instance

tree.sub(id)

Get the subtree rooted at target node.

Param:

• id {String|Number} - Target node ID

Return: {Tree|null} - Tree instance or null

tree.getDepth()

Get the maximum depth of the tree.

Return: {Number} - tree depth