Hooks

Hooks are actions performed before or after database lifecycle events.

Using model hooks helps keep your codebase DRY, providing convenient lifecycle code injection from wherever your hooks are defined.

A classic hook example is hashing the user password before saving the user to a database.

Defining Hooks

Hooks can be defined in a model class file via a closure, or by referencing any file.method handler in the app/Models/Hooks directory.

Binding Closure

const Model = use('Model')
const Hash = use('Hash')

class User extends Model {
  static boot () {
    super.boot()

    this.addHook('beforeCreate', async (userInstance) => {
      userInstance.password = await Hash.make(userInstance.password)
    })
  }
}

module.exports = User

In the example above, the beforeCreate closure is executed when creating a User model to ensure the user’s password is hashed before it’s saved.

Hook File

AdonisJs has a dedicated app/Models/Hooks directory to store model hooks.

Use the make:hook command to create a hook file:

> adonis make:hook User
Output
✔ create  app/Models/Hooks/UserHook.js

Open the new UserHook.js file and paste in the code below:

app/Models/Hooks/UserHook.js
'use strict'

const Hash = use('Hash')

const UserHook = exports = module.exports = {}

UserHook.hashPassword = async (user) => {
  user.password = await Hash.make(user.password)
}

With a hook file.method defined, we can remove the inline closure from our previous example and instead reference the hook file and method like so:

const Model = use('Model')

class User extends Model {
  static boot () {
    super.boot()
    this.addHook('beforeCreate', 'UserHook.hashPassword')
  }
}

module.exports = User

Aborting Database Operations

Hooks can abort database operations by throwing exceptions:

app/Models/Hooks/UserHook.js
UserHook.validate = async (user) => {
  if (!user.username) {
    throw new Error('Username is required')
  }
}

Lifecycle Events

Below is the list of available database lifecycle events to hook into:

Event Description

beforeCreate

Before creating a new record.

afterCreate

After a new record is created.

beforeUpdate

Before updating a record.

afterUpdate

After a record has been updated.

beforeSave

Before creating or updating a new record.

afterSave

After a new record has been created or updated.

beforeDelete

Before removing a record.

afterDelete

After a record is removed.

afterFind

After a single record is fetched from the database.

afterFetch

After the fetch method is executed. The hook method receives an array of model instances.

afterPaginate

After the paginate method is executed. The hook method receives two arguments: an array of model instances and the pagination metadata.