Inspired Javascript Tree UI Element
JavaScript HTML CSS
Latest commit ec97f85 Feb 22, 2017 @viveleroi viveleroi committed on GitHub Merge pull request #122 from xavistp/master
Search fixes. Fixes #121

Inspire Tree

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Build Status

Inspire Tree is a performance-driven javascript-based UI tree component, built for the modern web. Inspired by our need for one - the only existing solution which met our feature needs was a nightmare to develop for.


  • Robust API.
  • Events everywhere.
  • No required external dependencies.
  • Load data directly, via promises, or callbacks.
  • Load child nodes upfront or dynamically (or a mix of both).
  • Tri-state checkboxes (optional).
  • Multiselect (optional).
  • Inline editing (optional).
  • Search by plain string, RegExp, custom matcher, or external resources (optional).
  • Sorting (optional).
  • AMD and CommonJS support (RequireJS, Node/Webpack).
  • Supports multiple instances on a single page.
  • API methods to simplify moving nodes between instances.
  • Solid coverage by automated tests.
  • Built for IE10+.

DOM Renderer

  • Can be replaced with a custom renderer (see details below) for native framework support.
  • Virtual DOM for blazing fast change rendering.
  • Valid HTML structure.
  • Clean and easy-to-override CSS.
  • Modular SASS for custom compilation.
  • Keyboard navigation.
  • Custom context menu (optional).
  • Drag and Drop between tree instances (optional).


  • Node: npm install -save inspire-tree or
  • Bower bower install --save inspire-tree

The dist directory contains several versions:

  • bundled - Includes stripped-down version of lodash, has no external dependencies.
  • core - Excludes DOM rendering logic, for those using a custom renderer.
  • min - Minified source for production use.


In most use-cases you need to provide a target DOM element and a source of data:

var tree = new InspireTree({
    target: '.tree',
    data: $.getJSON('sample-data.json')

Data objects must have at least a text property. Additional properties are listed below in "Node Configuration".

If you're using a custom DOM renderer (see below), the target property is optional.

Data Loading and Initialization Errors

When you define a data loader in the InspireTree constructor, the promise isn't accessible, and this can consume errors that you should be aware of. There are a few choices:

  • If data was provided to the constructor, InspireTree will automatically throw any errors. However, errors from future calls will only be available through the load() method's promise or the data.loaderror event.
  • Listen to the data.loaderror event. All load errors, including initial errors, emit this event.
  • Load the data after tree initialization: tree.load(data).catch(function(err) { ... }).

API Docs

Tree Configuration

  • allowLoadEvents - Array of state-change events to fire for pre-set states.
  • checkbox
    • autoCheckChildren - Automatically check/uncheck children when parent toggled.
  • contextMenu - Array of choices (object with text property, handler function) for a custom context menu.
  • data - An array, promise, or callback function.
  • deferredLoading - Enable deferred loading. (See "Deferrals" section below.)
  • dom
    • autoLoadMore - Automatically triggers "Load More" links on scroll. Used with deferrals.
    • deferredRendering - Only render nodes as the user clicks to display more. (See "Deferrals" section below.)
    • nodeHeight - Height (in pixels) of your nodes. Used with deferrals, if pagination.limit not provided.
    • showCheckboxes - Show checkbox inputs.
  • dragTargets - Array of other tree elements which accept drag/drop.
  • editable - Allow inline editing.
  • editing (defaults to true if editable is true)
    • add - Allow user to add nodes.
    • edit - Allow user to edit existing nodes.
    • remove - Allow user to remove nodes.
  • nodes
    • resetStateOnRestore - Reset node state to defaults when restored.
  • pagination
    • limit - How many nodes are rendered/loaded at once. Used with deferrals. Defaults to nodes which fit in the container.
  • renderer - Function which returns a custom renderer (see below).
  • search
    • matcher - Custom search executor (for custom/external handling of entire search). Must be a function which accepts a query and resolve/reject arguments.
    • matchProcessor - Custom handler for search matches. Must be a function which accepts a TreeNodes argument.
  • selection
    • allow - Dynamically determine selectable boolean for a node.
    • autoDeselect - Prevent automatic deselection.
    • autoSelectChildren - Auto-select children when a parent node is selected, regardless of their visibility.
    • disableDirectDeselection - Disallow deselecting a node by clicking on it while selected.
    • mode - default or checkbox. Checkbox mode auto-selects children, doesn't auto deselect.
    • multiple - Allow multiple nodes to be selected at a time.
    • require - Require at least one selected node.
  • showCheckboxes - Show checkboxes in DOM. (Defaults to true if selection.mode === 'checkbox').
  • sort - Property to sort by, or a custom sort function.
  • tabindex - Define a tab index for the tree container (used for key nav).
  • target - An Element, selector, or jQuery object.

Node Configuration

  • text - Text used in display.
  • id - Unique ID. If missing, one will be generated.
  • children - An array of child nodes.
  • a.attributes - Custom attributes for this node's a.
  • li.attributes - Custom attributes for this node's root li.
  • itree - An object used to describe initial tree values:
    • icon - Custom icon for the anchor.
    • state.collasped - Set initial collapsed state.
    • state.focused - Node has UI focus.
    • state.hidden - Set initial visibility.
    • state.loading - Dynamic load of children in progress.
    • state.removed - Soft removed. Never shown until restored.
    • state.selectable - Allow selection.
    • state.selected - Set initial selection.


Events are triggered to inform you of changes or user interaction. Listeners are always registered on tree.on. Methods available in our event system are described at EventEmitter2.

tree.on('', function(event, node) {
    // node clicked!

Event List

  • children.loaded - (TreeNode node) - Children were dynamically loaded for a node.
  • data.loaded - (Array nodes) - Data has been loaded successfully (only for data loaded via xhr/callbacks).
  • data.loaderror - (Error err) - Loading failed.
  • model.loaded - (Array nodes) - Data has been parsed into an internal model.
  • node.added - (TreeNode node) - Node added.
  • node.blurred - (TreeNode node) - Node lost focus.
  • node.checked - (TreeNode node) - Node checked.
  • - (Event event, TreeNode node) - User clicked node.
  • node.collapsed - (TreeNode node) - Node collapsed.
  • node.contextmenu - (Event event, TreeNode node) - User right-clicked node.
  • node.dblclick - (Event event, TreeNode node) - User double-clicked node.
  • node.deselected - (TreeNode node) - Node deselected.
  • node.dropin - (TreeNode node) - Tree has received a new node via drop.
  • node.dropout - (TreeNode node), (Element elem) - Node dropped into a valid target.
  • node.expanded - (TreeNode node) - Node expanded.
  • node.focused - (TreeNode node) - Node focused.
  • node.hidden - (TreeNode node) - Node hidden.
  • node.paginate - (TreeNode context), (Object pagination) (Event event) - Nodes were paginated. Context is undefined when for the root level.
  • - (TreeNode node), (String property), (Mixed oldValue), (Mixed) newValue) - A node's root property has changed.
  • node.removed - (object node) - Node removed.
  • node.restored - (TreeNode node) - Node restored.
  • node.selected - (TreeNode node) - Node selected.
  • node.state.changed - (TreeNode node), (String property), (Mixed oldValue), (Mixed) newValue) - A node state boolean has changed.
  • node.shown - (TreeNode node) - Node shown.
  • node.softremoved - (TreeNode node) - Node soft removed.
  • node.unchecked - (TreeNode node) - Node unchecked.

Overriding DOM Events

In rare cases, you may need to override our default DOM event handlers. To assist with this, those events provide a preventTreeDefault method.

tree.on('', function(event, node) {
    event.preventTreeDefault(); // Cancels default listener

In these cases, it will be up to you to ensure any further logic has been implemented.

However, the original handler is passed as an argument, which still allows you to execute it when you're ready.

tree.on('', function(event, node, handler) {
    event.preventTreeDefault(); // Cancels default listener
    // do some custom logic
    handler(); // call the original tree logic

Only DOM-based events support this:, node.dblclick, node.contextmenu

API Basics

Each Inspire Tree instance returns an API object.

All methods not specific to existing node/s are found directly on the API:

tree.addNode({ text: 'Example' });


Each incoming javascript object is wrapped as a TreeNode, which aliases methods useful on a single node.



Multiple TreeNodes are contained within an Array-like object.

TreeNodes maps several TreeNode methods so you can invoke them on all nodes in the collection, or recursively down the nodes and their children.

Expands only root nodes inside this collection:


Expands root nodes and their children inside this collection:


Global TreeNodes Methods

Most TreeNodes methods are mapped to the tree instance to ease working with all nodes. Instead of using tree.nodes().someMethod() you can use tree.someMethod().


For those working with massive datasets, InspireTree offers several additional features to help reduce initial load burdens.

Deferred Rendering

Deferred Rendering progressively renders loaded nodes as the user scrolls or clicks a Load More link.

To work properly, you need to enable dom.deferredRendering in the configuration.

A "Load More" link will show at the bottom of each section which has more nodes than are initially allowed.

Deferred Loading

Deferred Loading works exactly like deferred rendering, except nodes are loaded in paginated chunks.

  1. Enable deferredLoading in the config.
  2. Pass a count of total nodes to the data callback. This way, inspire tree knows how many nodes remain.
data: function(node, resolve, reject, pagination) {
    // nodes = subset of total nodes, 1000 = total rows
    resolve(nodes, 1000);
  1. Set pagination.limit in the config if the default doesn't suit you.
  2. A fourth object, pagination is passed to the data callback. It contains the current limit/total for the context being loaded. If node is undefined, the pagination object refers to root level nodes, otherwise it refers to children of the node.

Note: Deferred rendering and loading may be used together but there's no reason to.

Custom Rendering

While Inspire Tree comes with a super-fast virtual DOM engine for element rendering, there are times when you need your own. Useful for integrating with existing engines like Angular, React, etc.

  1. Use only the inspire-tree-core.js file. This excludes our DOM code.
  2. Set the renderer option to a function which returns an object with the following methods. If/how you implement them depends on your rendering engine.

  • applyChanges - Called when core has altered something which will impact rendering.
  • attach - Called on load to attach to a given HTML element.
  • batch - Pause live rendering because multiple changes are coming.
  • end - Batch changes are done, rendering may resume.

Again, you may not need to implement these depending on how you render the data.

Your custom rendering function will be given the tree instance as an argument.

var tree = new InspireTree({
    target: '.tree',
    data: [],
    renderer: function(tree) {
        return {
            applyChanges: function() {},
            attach: function() {},
            batch: function() {},
            end: function() {}


  • available - Node is not soft-removed or hidden.
  • deepest - Nodes without any children.
  • visible - Node is visible to the user. It's ancestors are not hidden/collapsed/removed.


Recursing Flattened Arrays

Methods which return flattened arrays intentionally leave their hierarchy pointers intact. This means that while you have a flat array, you also have reference to parent/child elements. This can interfere with recursive methods because they'll iterate both the array elements and their children.

This will only impact a small number of methods. For example:


... will duplicate nodes because deepest iterates the array and recurses through children.

Possible solutions:

  • Reverse the order: tree.deepest().available()
  • Avoid flattened arrays: tree.available(true).deepest()