TreeModel

Manipulate and traverse tree-like structures in javascript.

For download and demos, please visit TreeModel website.

Installation

Node

TreeModel is available as an npm module so you can install it with npm install tree-model and use it in your script:

var TreeModel = require('tree-model'),
    tree = new TreeModel(),
    root = tree.parse({name: 'a', children: [{name: 'b'}]});

Browser

Visit TreeModel website to download browser-ready bundles.

API Reference

Create a new TreeModel

Create a new TreeModel with the given options.

var tree = new TreeModel(options)

Valid properties for the options object are:

• childrenPropertyName - The name for the children array property. Default is children;
• modelComparatorFn - A comparator function to sort the children when parsing the model and adding children. The default order policy is to keep the parsed order and append new children. The comparator function receives the model for two nodes just like the Array.sort function. The provided sort algorithm is stable.

Parse the hierarchy object

Parse the given user defined model and return the root Node object.

Node tree.parse(model)

Is Root?

Return true if this Node is the root, false otherwise.

Boolean node.isRoot()

Add a child

Add the given node as child of this one. Return the child Node.

Node parentNode.addChild(childNode)

Get the node path

Get the array of Nodes representing the path from the root to this Node (inclusive).

Array<Node> node.getPath()

Delete a node from the tree

Drop the subtree starting at this node. Returns the node itself, which is now a root node.

Node node.drop()

Warning - Dropping a node while walking the tree is not supported. You must first collect the nodes to drop using one of the traversal functions and then drop them. Example:

root.all( /* predicate */ ).forEach(function (node) {
  node.drop();
});

Find a node

Starting from this node, find the first Node that matches the predicate and return it. The predicate is a function wich receives the visited Node and returns true if the Node should be picked and false otherwise.

Node node.first(predicate)

Find all nodes

Starting from this node, find all Nodes that match the predicate and return these.

Array<Node> node.all(predicate)

Walk the tree

Starting from this node, traverse the subtree calling the action for each visited node. The action is a function which receives the visited Node as argument. The traversal can be halted by returning false from the action.

node.walk([options], action, [context])

Note - first, all and walk can optionally receive as first argument an object with traversal options. Currently the only supported option is the traversal strategy which can be any of the following:

• {strategy: 'pre'} - Depth-first pre-order [default];
• {strategy: 'post'} - Depth-first post-order;
• {strategy: 'breadth'} - Breadth-first.

These functions can also take, as the last parameter, the context on which the action will be called.

Contributing

Running Tests

The tests require npm libraries mocha, chai, and sinon. To install them run: npm install

To run tests, type: npm test

Code Linting

Install jshint: npm install -g jshint

Check src and tests: jshint index.js test/test.js