A mongoose plugin implementing the nested set pattern for mongoose models
Latest commit e819afc Feb 14, 2015 @luccastera luccastera README formatting



A mongoose plugin implementing the nested set pattern for mongoose models


var mongoose = require('mongoose'),
    NestedSetPlugin = require('mongoose-nested-set'),
    Schema = mongoose.Schema;


var UserSchema = new Schema({
  username: {type: String}

// Include plugin

var User = mongoose.model('User', UserSchema);


The plugin adds the following attributes to the model:

  • lft: holds the left value of the node in the tree

  • rgt: holds the right value of the node in the tree

  • parentId: holds the _id of the parent node


The plugin supports the following options:

  • groupingKey: a key to denote that elements in the tree belong to a group. This is helpful to maintain multiple trees within the same collection. Eg. in the tests we have two trees, grouped by the attribute 'organization' on the model, in that case we've given the { groupingKey: 'organization' } as options.


Examples are based on the following tree:

The Office

User.findOne({username: 'michael'}, function(err, michael) {
  User.rebuildTree(michael, 1, function() {
    // at this point, the tree is built and every node has a lft and rgt value.
    michael.descendants(function(err, data) {
      // data contains a list of michael descendants
    console.log('Is Michael a leaf node?', michael.isLeaf());
    console.log('Is Michael a child node?', michael.isChild());

For more examples, see our test suite.


Static methods

  • Model.rebuildTree(rootNode, leftValueOfRootNode, callback)

Instance methods that return values:

The following methods return a boolean:

  • isLeaf()

  • isChild()

  • isDescendantOf(otherNode)

  • isAncestorOf(otherNode)

Instance methods that use a callback function:

The following methods must be used with a callback. The callback method will be called with two arguments: the first argument is the error object (if there was no error, it will be null) and the second argument is the data returned.

  • selfAndAncestors(callback)

  • parent(callback)

  • ancestors(callback)

  • selfAndChildren(callback)

  • children(callback)

  • selfAndDescendants(callback)

  • descendants(callback)

  • level(callback)

  • selfAndSiblings(callback)

  • siblings(callback)

Related Links/Resources


To run the tests:

npm test


Feb 14, 2015: Version 0.0.7

  • Converted methods to follow mongoose params model #11

Nov 23, 2014: Version 0.0.6

  • New Feature: added groupingKey option

Jun 30, 2013: Version 0.0.5

  • Added compound index on lft,rgt for selfAndDescendants and selfAndAncestors queries
  • A few small refactorings of tests

Oct 26, 2012: Version 0.0.4

  • Bug fixes

Oct 25, 2012: Version 0.0.3

  • Bug fixes

Oct 25, 2012: Version 0.0.2

  • Better tests
  • Code cleanup
  • Updated package.json to latest dependencies
  • Added mongodb indexes on lft, rgt, and parentId