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'}]});

TypeScript

Type definitions are already bundled with the package, which should just work with npm install.

You can maually find the definition files in the types folder.

Browser

Visit TreeModel website to download browser-ready bundles.

Questions?

If you have any doubt using this library please post a question on stackoverflow tagged with treemodel.

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()

Has Children?

Return true if this Node has one or more children, false otherwise.

Boolean node.hasChildren()

Add a child

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

Node parentNode.addChild(childNode)

Add a child at a given index

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

Node parentNode.addChildAtIndex(childNode, index)

Set the index of a node among its siblings

Sets the index of the node among its siblings to the given value. Return the node itself.

Node node.setIndex(index)

Get the index of a node among its siblings

Gets the index of the node relative to its siblings. Return the index value.

Int node.getIndex()

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

Setup

Fork this repository and run npm install on the project root folder to make sure you have all project dependencies installed.

Code Linting

Run npm run lint

This will check both source and tests for code correctness and style compliance.

Running Tests

Run npm test

Type definitions

To modify the type definitions, look inside the types folder. index.d.ts contains the definition and tree-model-tests.ts contains type tests.

To verify changes:

Run npm run dtslint.