sequelize-nested-sets

Nested Sets Behavior for Sequelize

Behavior for storing and managing nested sets

Installation

npm install --save sequelize-nested-sets

Configuring

The library works as a wrapper over the model before initialization.

Configure model:

// yourModel.js
const { Model } = require('sequelize');
const ns = require('sequelize-nested-sets');
 
// with class extending Model
module.exports = (sequelize, DataTypes) => {
  class Menu extends Model {
    // additional methods, associations
  }
 
  return ns(sequelize, 'menu', {
      name: DataTypes.STRING,
    }, {
      tableName: 'menu',
      treeAttribute: 'tree',
    },
    Menu
  );
};

// or without ES6 classes
module.exports = (sequelize, DataTypes) => {  
  const Menu = ns(sequelize, 'menu', {
      name: DataTypes.STRING,
    }, {
      tableName: 'menu',
      treeAttribute: 'tree',
    }
  );
  return Menu;
};

DB Table Structure:

Your table must have follow columns:

• lft (int unsigned NOT NULL)
• rgt (int unsigned NOT NULL)
• depth (int unsigned NOT NULL)
• tree (int unsigned NOT NULL) (if you use multiple tree)

You can specify custom column names in options

Nested Sets Options

ns(sequelize, modelName, attributes, [options], [Model])

To use multiple tree mode set treeAttribute.

Adds nested set behavior using the model wrapper

Param	Type	Default	Description
sequelize	sequelize		Ready sequelize object with connection
modelName	string		Model name
attributes	object		Model attributes
[options]	object	{}	Sequelize and Nested sets options
[options.treeAttribute]	string	false	Column name for tree id, specify for use multiple tree
[options.leftAttribute]	string	"lft"	Column name for left attribute
[options.rightAttribute]	string	"rgt"	Column name for right attribute
[options.depthAttribute]	string	"depth"	Column name for depth attribute
[Model]	Model		Extended Model class

Usage

Moving, Creating node

Making a root node

To make a root node

const menu = Menu.build({ name: 'Main Menu' });
await menu.makeRoot();

The tree will look like this

— Main Menu

Prepending a node as the first child of another node

To prepend a node as the first child of another node

const productPage = Menu.build({ name: 'Product Page' });
await productPage.prependTo(menu);

The tree will look like this

— Main Menu
— — Product Page

Appending a node as the last child of another node

To prepend a node as the last child of another node

const faqPage= Menu.build({ name: 'FAQ Page' });
await faqPage.appendTo(menu);

The tree will look like this

— Main Menu
— — Product Page
— — FAQ Page

Inserting a node before another node

To insert a node before another node

const homePage = Menu.build({ name: 'Home Page' });
await homePage.insertBefore(productPage);

The tree will look like this

— Main Menu
— — Home Page
— — Product Page
— — FAQ Page

Inserting a node after another node

To insert a node after another node

const contactPage = Menu.build({ name: 'Contact Page' });
await contactPage.insertBefore(faqPage);

The tree will look like this

— Main Menu
— — Home Page
— — Product Page
— — FAQ Page
— — Contact Page

Getting nodes

Getting the root nodes

To get all the root nodes

const roots = await Menu.roots();

Getting the leaves nodes

To get all the leaves nodes

const leaves = await Menu.leaves();

To get all the leaves of a node

const menu = await Menu.findOne({ where: { name: 'Main Menu' } });
const leaves = await menu.leave();

Getting children of a node

model.children([depth = null], [options = {}]);

To get all the children of a node

const menu = await Menu.findOne({ where: { name: 'Main Menu' } });
const children = await menu.children();

To get the first level children of a node

const menu = await Menu.findOne({ where: { name: 'Main Menu' } });
const children = await menu.children(1);

To get the children by condition

const menu = await Menu.findOne({ where: { name: 'Main Menu' } });
const children = await menu.children(null, { where: { name: 'FAQ Page' } });

Getting parents of a node

model.parents([depth = null], [options = {}]);

To get all the parents of a node

const faqPage = await Menu.findOne({ where: { name: 'FAQ Page' } });
const parents = await faqPage.parents();

To get the first parent of a node

const faqPage = await Menu.findOne({ where: { name: 'FAQ Page' } });
const parents = await faqPage.parents(1);

To get the parent by condition

const faqPage = await Menu.findOne({ where: { name: 'FAQ Page' } });
const parents = await menu.parents(null, { where: { name: 'Main Menu' } });

All methods see in wiki