iron-tree

This package builds a tree and gives a lot of useful methods for managing a tree and its nodes

Install

npm install @denq/iron-tree --save

Base usage

// create tree
const object = { id: 1, title: 'Root' };
const tree = new Tree(object);

// add nodes
const regularObject = { id:2, title: 'Node 2'}
tree.add((parentNode) => {
  return parentNode.get('id') === 1;
}, regularObject);

// contains node
const targetNode = tree.contains((currentNode) => {
  return currentNode.get('id') === 2;
});  

// remove node
const result = tree.remove((currentNode) => {
  return currentNode.get('id') === 2;
});

// traversal
const criteria = (currentNode) => currentNode.get('id') === 1;
tree.traversal(criteria, (currentNode) => {
  currentNode.set('some', true);
});

// getPath
const criteria = (currentNode) => currentNode.get('id') === 6;
const targetNode = tree.contains(criteria);
const path = targetNode.getPath();
const pathString = path
  .map((item) => item.get('id'))
  .join(',');

function compareById(vector) {
  return (a, b) => {
    const aid = Number(a.get('id'));
    const bid = Number(b.get('id'));
    if (aid > bid) {
      return vector ? 1 : -1;
    } else if (aid < bid) {
      return vector ? -1 : 1;
    } else {
      return 0
    }
  };
}
tree.sort(compareById(false));  // desc

The following are the other methods available.

---

Tree

This is the class of tree management.

Properties

• rootNode Root tree node
  • type Node

Methods

• contstructor(object)

  • params
    • object - json object. Optional
  • return IronTree
  • example

    const object = { id: 1, title: 'Root' };
    const tree = new Tree(object);

• .add(criteria, object) Adds a node to the tree if the criterion is true.

  • params
    • criteria(Node) - function or string. If string then criteria is "root"
    • object - content for the node
  • return IronTree
  • examples

  const object = { id: 1, title: 'Root' };
  const tree = new Tree();
  const resultTree = tree.add('root', object);

  const regularObject = { id:2, title: 'Node 2'}
  const resultTree = tree.add((parentNode) => {
      return parentNode.get('id') === 1;
  }, regularObject);

• .remove(criteria) Removes a node from a tree if the criterion is true.

  • params
    • criteria(Node) - return boolean
  • return boolean
  • examples

  const result = tree.remove((currentNode) => {
      return currentNode.get('id') === 7;
  });

• .contains(criteria) Searches for a node in a tree according to the criterion.

  • params
    • criteria(Node) - return boolean
  • return Node
  • examples

  const targetNode = tree.contains((currentNode) => {
      return currentNode.get('id') === 7;
  });

• .sort(compare) Sorts a tree.

  • params
    • compare(a:Node, b:Node) - comparison function
  • return null
  • examples

  function compareById(vector) {
      return (a, b) => {
          const aid = Number(a.get('id'));
          const bid = Number(b.get('id'));
          if (aid > bid) {
            return vector ? 1 : -1;
          } else if (aid < bid) {
            return vector ? -1 : 1;
          } else {
            return 0
          }
      };
  }
  tree.sort(compareById(false));  //Desc

• .move(criteria, destination) Moves the desired branch or node to the node or branch of the destination, according to the criteria.

  • params
    • criteria(Node) - callback
    • destination(Node) - callback
  • return boolean
  • examples

  const search = (currentNode) => currentNode.get('id') === 7;
  const destination = (currentNode) => currentNode.get('id') === 3;
  const result = tree.move(search, destination);

• .traversal(criteria, callback) Bypasses the tree and, according to the criterion, calls a function for each node.

  • params
    • criteria(Node) - return boolean
    • callback(Node)
  • return null
  • examples

  const criteria = (currentNode) => currentNode.get('id') === 7;
  tree.traversal(criteria, (currentNode) => {
      currentNode.set('some', true);
  });

  tree.traversal(null, (currentNode) => {
      if (currentNode.get('id')%2 === 0) {
        currentNode.set('some', true);
      }
  });

• .toJson(options) Represents a tree in the form of a json format.

  • params
    • options - object. Optional
      • empty_children - Type boolean. Allow empty children. Default true
      • key_children - Type string. Field name for children. Default children
  • return object
  • examples

  const json = tree.toJson();

---

Node

This is the node management class.

Properties

• content Content of the node
  • type object
• children Children of the node
  • type array
• length Number children of the node
  • type number

Methods

• constructor(json)

  • params
    • json - simple json object
  • examples

  const rootContent = {
    id: 1,
    name: 'Root',
  }
  let node = new Node(rootContent);

• .add(child) Adding a child to the node.

  • return Node - created node
  • params
    • child - type object/json
  • examples

  const rootContent = {
    id: 1,
    name: 'Root',
  }
  let node = new Node(rootContent);
  const childNode = node.add({ id: 2, name: 'Two node'});

• .remove(criteria) Removing a child node according to the criterion.

  • return - removed Node
  • params
    • criteria - criteria function for removing nodes
  • examples

  const removedNodes = node.remove((itemNode) => {
      return itemNode.get('id') === 3;
  })

• .get(path) Access to node content by field name.

  • return mixed
  • params
    • path - key name for object in node. For example id or fullname, etc...
  • examples

    node.get('id'); // 1
    node.get('name') // "Some name"

• .set(path, value) Setting a value or creating a new field in the contents of a node.

  • return boolean
  • params
    • path - String field name
    • value - mixed
  • examples

  node.set('id', 100)); // returned `true`. Node.content.id = 100
  node.get('id'); // 100

• .sort(compare) Sorting child nodes

  • return null
  • params
    • compare - custom function for sorting
  • examples

  function compareById(vector) {
      return (a, b) => {
        const aid = Number(a.get('id'));
        const bid = Number(b.get('id'));
        if (aid > bid) {
          return vector ? 1 : -1;
        } else if (aid < bid) {
          return vector ? -1 : 1;
        } else {
          return 0
        }
      };
  }
  node.sort(compareById(false));

• .traversal(criteria, callback) Bypassing child nodes according to the criterion and applying function to them.

  • return null
  • params
    • criteria - function criteria each nodes
    • callback - function fire when criteria is true for node
  • examples

  // for all nodes
  node.traversal(null, (currentNode) => {
    const name = currentNode.get('name');
    currentNode.set('name', `${name}!`);  // Last symbol "!"
  });

  // only for node.id == 3
  node.traversal((currentNode) => currentNode.get('id') === 3, (currentNode) => {
    const name = currentNode.get('name');
    currentNode.set('name', `${name}!`);  // Last symbol "!"
  });

• .getPath() This method return array Nodes from root node to current node. It maybe helpful for breadcrumbs.

  • return Array
  • exampels

  const path = targetNode.getPath();
  const pathString = path
    .map((item) => item.get('id'))
    .join(','); // 1,3,4,5,6

---

TDD

npm test