Hooks introducing computed properties

[baybal]

I have a case where I want to add a property onto the ORM output, but I don't want it to be saved as a column during save stages.

If I am to add a property in the "afterFind." and attempt to save, or manipulate the record will lead to that property being written back to the DB, unlike if it was just a synchronous computed property.

[aayush123]

I think you are talking about computed properties

[baybal]

Computed properties cannot be asynchronous

[thetutlage]

Can you share some code that you expect to work, but not sure if it will work?

[baybal]

import {
  setTimeout,
} from 'timers/promises';

In the boot method

this.addHook('afterFind', async m=>m.test = await setTimeout(1000, 'test'));

then

const user = await user.find(123);
user.name = 'asdasdasd';
await user.save()

It will bail out with postgres complaining that there is no test column

[thetutlage]

Can you share the model class as well?

[baybal]

class User extends Model {
  // When this model is booted (happens only once)
  static boot () {
    super.boot()

    this.addHook('afterFind', async m=>m.test = await setTimeout(1000, 'test'));
  }

  static get traits () {
    return [
      '@provider:Adonis/Acl/HasRole',
      '@provider:Adonis/Acl/HasPermission'
    ]
  }

  static get primaryKey () {
    return 'uuid'
  }

  // What is visible/hidden by pulling this model
  static get hidden () {
    return ['id', 'password']
  }

  static get authData () {
    return [
      'uuid', 'last_name', 'first_name', 'email', 'role', 'color', 'created_at',
      'updated_at', 'username', 'avatar_path'
    ]
  }

  /**
   * Relationships
   */

  mp3s () {
    return this.hasMany('App/Models/Mp3', 'uuid', 'created_by')
  }

  tokens () {
    return this.hasMany('App/Models/Token', 'uuid', 'user_id')
  }

  // eslint-disable-next-line camelcase
  user_groups () {
    return this.belongsToMany('App/Models/UserGroup', 'user_uuid', 'user_group_uuid', 'uuid', 'uuid')
  }

  /**
   * Mutators
   */

  setLastName (lastName) {
    return lastName ? string.ucfirst(lastName) : null
  }

  setFirstName (firstName) {
    return firstName ? string.ucfirst(firstName) : null
  }
}