AdonisJS Hook Before Save

AdonisJS is a powerful and flexible Node.js web framework that allows developers to build efficient and scalable web applications. One of its many features is the ability to use hooks, which are functions that are executed before or after certain events are triggered in the application.

In this article, we will be focusing on the "before save" hook in AdonisJS, which is executed before a model is saved to the database.

What is a Hook?

Hooks are essentially functions that allow you to manipulate data or perform certain actions before or after a specific event occurs in your application. For example, you can use hooks to validate form data before it is saved to the database, or to send an email notification after a new user has been created.

Hooks can be defined at the application, model, or controller level, and can be registered using the Hooks provider in AdonisJS.

The Before Save Hook

The "before save" hook is a specific type of hook that is executed before a model instance is saved to the database. This allows you to manipulate the data that is being saved or perform validation checks before the data is persisted to the database.

To define a "before save" hook in AdonisJS, you can use the beforeSave method on your model. For example, if you have a User model, you can define a "before save" hook to ensure that the email address is lowercase before it is saved to the database:

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

    this.beforeSave(async (userInstance) => {
      userInstance.email = userInstance.email.toLowerCase()
    })
  }
}

In this example, we define a beforeSave hook that takes a userInstance parameter (which represents the model instance being saved). We then set the email address to lowercase using the toLowerCase() method.

Conclusion

Hooks are a powerful feature in AdonisJS that allow you to manipulate data and perform actions before or after specific events occur in your application. The "before save" hook is an especially useful hook that lets you manipulate data before it is saved to the database.

In this article, we covered how to define a "before save" hook in AdonisJS and provided an example that demonstrates how you can use this hook to ensure that email addresses are saved in lowercase. With this knowledge, you can now use hooks to build more sophisticated and efficient web applications using AdonisJS!