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