passthrough

Associations in Dream can be defined with a passthrough constraint. This means that the only way these associations can be loaded is if data is passed through using a passthrough method. This is useful for localization patterns where the locale changes per request and is driven by headers:

export default class Post extends ApplicationModel {
  @deco.HasOne('LocalizedText', {
    polymorphic: true,
    on: 'localizableId',
    and: { locale: DreamConst.passthrough },
  })
  public currentLocalizedText: LocalizedText
}

const reloadedUser = await user
  .passthrough({ locale: 'es-ES' })
  .load('posts', 'currentLocalizedText')
  .execute()

For serializer-driven responses, pass the same value through both channels when needed:

const locale = this.castParam('Accept-Language', 'string', { enum: LocalesEnumValues })

const place = await Place
  .passthrough({ locale })      // association constraints
  .preloadFor('forGuests')
  .findOrFail(this.castParam('id', 'uuid'))

this.serializerPassthrough({ locale }) // serializer callbacks
this.ok(place)