filter
Filter a tree by a predicate, keeping matching nodes along with their ancestors so the surviving branches remain navigable.
Usage
The filter method filters a tree based on a predicate function. Unlike array's filter, it retains all nodes that satisfy the condition as well as their ancestor nodes, thereby maintaining the tree structure.
example.ts
import { Tree } from '@movk/core'
const tree = [
{ id: 1, name: 'Root', children: [
{ id: 2, name: 'Active User' },
{ id: 3, name: 'Inactive User', children: [{ id: 4, name: 'Active Child' }] }
] }
]
const activeTree = Tree.filter(tree, ({ node }) => node.name.includes('Active'))
/*
activeTree will be:
[
{ id: 1, name: 'Root', children: [
{ id: 2, name: 'Active User', children: [] },
{ id: 3, name: 'Inactive User', children: [{ id: 4, name: 'Active Child', children: [] }] }
]}
]
*/
API
filter<T extends TreeNode>(tree: T[], predicate: (context: VisitorContext<T>) => boolean, config?: TreeConfig): T[]
Parameters
tree
T[] required
The source tree array.
predicate
(context: VisitorContext<T>) => boolean required
A predicate function called for each node in the tree. If the function returns
true, that node and all its ancestor nodes will be retained in the result.
The function receives a context object with the following properties:node
T
The node currently being processed.
depth
number
The depth of the node (root node is 0).
path
T[]
An array of nodes from the root to the current node (inclusive).
index
number
The index of the current node among its siblings.
config
TreeConfig
Configuration object for customizing the
id, pid, children key names in the tree structure.id
string
Optional. The key name for the node's unique identifier. Defaults to "id".
pid
string
Optional. The key name for the node's parent identifier. Defaults to "pid".
children
string
Optional. The key name for the children array. Defaults to "children".
Returns
T[]
Returns a new, filtered tree array.
Changelog
No recent changes