ds-tree

data structure - tree using javascript/typescript

How to install

npm i @share-code/ds-tree

Basic code to start

const dsTree = new DsTree({
  name: 'hello0',
  children: [{ name: 'hello0-0' }, { name: 'hello0-1' }, { name: 'hello1' }]
})

// Mutate your tree in here

dsTree.export()

Methods you can use

Common

search

You can find a node which satisfy the condition. This method use DFS algorithm to find node.

DFS algorithm will be stopped if satisfied condition node is founded.

If you use this method with dsTreeNode, it will traverse from current node

Return type: DsTreeNode | null

const dsTree = new DsTree({ name: 'hello0' })

dsTree.search((node) => node.getValue().name === 'hello0') // default algorithm is 'preorder'
dsTree.search((node) => node.getValue().name === 'hello0', {
  algorithm: 'preorder'
})
dsTree.search((node) => node.getValue().name === 'hello0', {
  algorithm: 'postorder'
})

searchAll

You can find nodes which satisfy the condition. This method use DFS algorithm to find node.

If you use this method with dsTreeNode, it will traverse from current node

Return type: DsTreeNode[]

const dsTree = new DsTree({ name: 'hello0' })

dsTree.searchAll((node) => node.getValue().name === 'hello0') // default algorithm is 'preorder'
dsTree.searchAll((node) => node.getValue().name === 'hello0', {
  algorithm: 'preorder'
})
dsTree.searchAll((node) => node.getValue().name === 'hello0', {
  algorithm: 'postorder'
})

walk

You can check the whole nodes in the tree with this method.

This method was maded to get the information. Not for mutation.

If you use this method with dsTreeNode, it will traverse from current node

Return type: void

const dsTree = new DsTree({
  name: 'hello0',
  children: [{ name: 'hello0-0' }, { name: 'hello0-1' }, { name: 'hello1' }]
})

// default algorithm is 'preorder'
dsTree.walk((node) => {
  console.log('depth: ' + node.getDepth())
})

// depth: 0
// depth: 1
// depth: 1
// depth: 1

dsTree.walk(
  (node) => {
    console.log('depth: ' + node.getDepth())
  },
  { algorithm: 'preorder' }
)

// depth: 0
// depth: 1
// depth: 1
// depth: 1

dsTree.walk(
  (node) => {
    console.log('depth: ' + node.getDepth())
  },
  { algorithm: 'postorder' }
)

// depth: 1
// depth: 1
// depth: 1
// depth: 0

DsTree

getRootNode

You can get root node.

Return type: DsTreeNode

const dsTree = new DsTree({ name: 'hello0' })

dsTree.getRootNode()

parse

You can parse tree form into dsTree form. This is useful when you add new child.

Return type: DsTreeNode

const dsTree = new DsTree({ name: 'hello0' })

dsTree.parse({ name: 'hello1', children: [] })

export

After finish your mutation with your tree, you can make original tree structure.

Return type: object

const dsTree = new DsTree({ name: 'hello0' })

dsTree.export() // return: { name: 'hello0', children: [] }

DsTreeNode

isRootNode

Check node is root node.

Return type: boolean

const dsTree = new DsTree({ name: 'hello0' })
const rootNode = dsTree.getRootNode()

rootNode.isRootNode() // true

getDepth()

Get depth of node. Root node is 0.

Return type: number

const dsTree = new DsTree({ name: 'hello0' })
const rootNode = dsTree.getRootNode()

rootNode.getDepth() // 0

getPath(fromTop: boolean = false)

get current node path

Return type: DsTreeNode[]

const dsTree = new DsTree({
  name: 'hello0',
  children: [
    {
      name: 'hello0-0'
    },
    {
      name: 'hello0-1',
      children: [{ name: 'hello0-1-0' }, { name: 'hello0-1-1' }]
    },
    {
      name: 'hello0-2'
    }
  ]
})

const searchedNode = dsTree.search(
  (node) => node.getValue().name === 'hello0-1-0'
)

searchedNode.getPath().forEach((node) => {
  console.log('node: ' + node.getValue().name)
})

// hello0-1-0
// hello0-1
// hello0

searchedNode.getPath(true).forEach((node) => {
  console.log('node: ' + node.getValue().name)
})

// hello0
// hello0-1
// hello0-1-0

getValue()

Get node value

I recommend not to change children values!

Return type: object

const dsTree = new DsTree({ name: 'hello0' })
const rootNode = dsTree.getRootNode()

rootNode.getValue() // { name: 'hello0' }

setValue(newValue: Partial | ((currentValue: DsTreeNode) => DsTreeNode))

Set node value

I recommend not to change children values!

Return type: object

const dsTree = new DsTree({ name: 'hello0' })
const rootNode = dsTree.getRootNode()

// case 01
rootNode.setValue({ name: 'hello7' })
rootNode.getValue() // { name: 'hello7' }

// case 02
rootNode.setValue((prev) => ({ ...prev, name: 'hello77' }))
rootNode.getValue() // { name: 'hello77' }

getParentNode()

Get parent node

Return type: DsTreeNode | null

const dsTree = new DsTree({
  name: 'hello0',
  children: [{ name: 'hello0-0' }, { name: 'hello0-1' }]
})
const rootNode = dsTree.getRootNode()

rootNode.getParentNode() // null

rootNode.getChildren()[0].getParentNode() // it's going to return rootNode

getSiblings(andSelf: boolean = false)

Get node siblings

Return type: DsTreeNode[]

const dsTree = new DsTree({
  name: 'hello0',
  children: [{ name: 'hello0-0' }, { name: 'hello0-1' }, { name: 'hello0-2' }]
})
const rootNode = dsTree.getRootNode()

rootNode
  .getChildren()[0]
  .getSiblings()
  .forEach((node) => {
    console.log('node value: ', node.getValue())
  })

// node value: { name: 'hello0-1' }
// node value: { name: 'hello0-2' }

rootNode
  .getChildren()[0]
  .getSiblings(true)
  .forEach((node) => {
    console.log('node value: ', node.getValue())
  })

// node value: { name: 'hello0-0' }
// node value: { name: 'hello0-1' }
// node value: { name: 'hello0-2' }

getIndex()

Get node index among siblings

Return type: number

const dsTree = new DsTree({
  name: 'hello0',
  children: [{ name: 'hello0-0' }, { name: 'hello0-1' }, { name: 'hello0-2' }]
})
const rootNode = dsTree.getRootNode()

rootNode.getChildren()[1].getIndex() // 1
rootNode.getChildren()[2].getIndex() // 2

setIndex(newIndex: number)

Get node index among siblings

Return type: void

const dsTree = new DsTree({
  name: 'hello0',
  children: [{ name: 'hello0-0' }, { name: 'hello0-1' }, { name: 'hello0-2' }]
})
const rootNode = dsTree.getRootNode()

rootNode.getChildren()[1].setIndex(0)

console.log(dsTree.export())

/*
{
  name: 'hello0',
  children: [{
    { name: 'hello0-1', children: [] },
    { name: 'hello0-0', children: [] },
    { name: 'hello0-2', children: [] }
  }]
}
*/

isFirstChild()

Check node is first child or not

Return type: boolean

const dsTree = new DsTree({
  name: 'hello0',
  children: [{ name: 'hello0-0' }, { name: 'hello0-1' }, { name: 'hello0-2' }]
})

const searchedNode00 = dsTree.search(
  (node) => node.getValue().name === 'hello0-0'
)

searchedNode00!.isFirstChild() // true

const searchedNode01 = dsTree.search(
  (node) => node.getValue().name === 'hello0-1'
)

searchedNode01!.isFirstChild() // false

isLastChild()

Check node is last child or not

Return type: boolean

const dsTree = new DsTree({
  name: 'hello0',
  children: [{ name: 'hello0-0' }, { name: 'hello0-1' }, { name: 'hello0-2' }]
})

const searchedNode00 = dsTree.search(
  (node) => node.getValue().name === 'hello0-2'
)

searchedNode00!.isLastChild() // true

const searchedNode01 = dsTree.search(
  (node) => node.getValue().name === 'hello0-1'
)

searchedNode01!.isLastChild() // false

getChildren()

Get node's children nodes

Return type: DsTreeNode[] | undefined | null

const dsTree = new DsTree({
  name: 'hello0',
  children: [{ name: 'hello0-0' }, { name: 'hello0-1' }, { name: 'hello0-2' }]
})
const rootNode = dsTree.getRootNode()

rootNode.getChildren().forEach((node) => {
  console.log('node name: ' + node.getValue().name)
})

// node name: 'hello0-0'
// node name: 'hello0-1'
// node name: 'hello0-2'

addChild(newNode: DsTreeNode)

add child at the very end of child index

Return type: void

const dsTree = new DsTree({
  name: 'hello0',
  children: [{ name: 'hello0-0' }, { name: 'hello0-1' }, { name: 'hello0-2' }]
})
const rootNode = dsTree.getRootNode()

rootNode.addChild({ name: 'hello0-3', children: [] })

rootNode.getChildren().forEach((node) => {
  console.log('node name: ' + node.getValue().name)
})

// node name: 'hello0-0'
// node name: 'hello0-1'
// node name: 'hello0-2'
// node name: 'hello0-3'

addChildAtIndex(newNode: DsTreeNode, index: number)

add child at the user specified index

Return type: void

const dsTree = new DsTree({
  name: 'hello0',
  children: [{ name: 'hello0-0' }, { name: 'hello0-1' }, { name: 'hello0-2' }]
})
const rootNode = dsTree.getRootNode()

rootNode.addChildAtIndex({ name: 'hello0-3', children: [] }, 1)

rootNode.getChildren().forEach((node) => {
  console.log('node name: ' + node.getValue().name)
})

// node name: 'hello0-0'
// node name: 'hello0-3'
// node name: 'hello0-1'
// node name: 'hello0-2'

drop()

Drop node

Return type: DsTreeNode

const dsTree = new DsTree({
  name: 'hello0',
  children: [
    {
      name: 'hello0-0'
    },
    {
      name: 'hello0-1',
      children: [{ name: 'hello0-1-0' }, { name: 'hello0-1-1' }]
    },
    {
      name: 'hello0-2'
    }
  ]
})
const rootNode = dsTree.getRootNode()

const secondChild = rootNode.getChildren()![1].drop()

console.log('secondChild parentNode: ', secondChild.getParentNode())
// secondChild parentNode: null
console.log('secondChild name: ', secondChild.getValue().name)
// secondChild name: hello0-1

secondChild.getChildren()!.forEach((node) => {
  console.log('node name: ', node.getValue().name)
})
// node name: hello0-1-0
// node name: hello0-1-1

rootNode.getChildren()!.forEach((node) => {
  console.log('node name: ', node.getValue().name)
})

// node name: 'hello0-0'
// node name: 'hello0-2'

License

MIT