Inject a repository into model class?

Question

i am using the Loopback4 framework. I try to inject a repository into some model class (documentRepository into userModelClass). I am not sure if it is possible to do something like that. The reason why i want to do this is because in the repository i have a method which returns all documents that are assigned to an user. Later there will be more models which have to use the same method.

This is the way i tried to inject my repository (constructor user model):

constructor(
    data?: Partial<User>,
    @repository(DokumentRepository) public dokumentRepository?: DokumentRepository
  )

When i am starting the application i am getting the following error in my console:

E:\workspace\compass\backend\node_modules\@loopback\repository\dist\decorators\repository.decorator.js:51
const stringOrModel = typeof modelOrRepo !== 'string' && !modelOrRepo.prototype.getId
                                                                      ^

TypeError: Cannot read property 'prototype' of undefined
    at Object.repository (E:\workspace\compass\backend\node_modules\@loopback\repository\dist\decorators\repository.decorator.js:51:75)
    at Object.<anonymous> (E:\workspace\compass\backend\dist\src\models\admin\user.model.js:266:29)
    at Module._compile (module.js:652:30)
    at Object.Module._extensions..js (module.js:663:10)
    at Module.load (module.js:565:32)
    at tryModuleLoad (module.js:505:12)
    at Function.Module._load (module.js:497:3)
    at Module.require (module.js:596:17)
    at require (internal/module.js:11:18)
    at Object.<anonymous> (E:\workspace\compass\backend\dist\src\repositories\admin\user.repository.js:19:22)
    at Module._compile (module.js:652:30)
    at Object.Module._extensions..js (module.js:663:10)
    at Module.load (module.js:565:32)
    at tryModuleLoad (module.js:505:12)
    at Function.Module._load (module.js:497:3)
    at Module.require (module.js:596:17)
Waiting for the debugger to disconnect...

Process finished with exit code -1073741510 (0xC000013A: interrupted by Ctrl+C)

Maybe someone of you have an idea how to inject a repository to a model or can tell my why that is not possible...

score 2 · Answer 1 · answered Sep 02 '19 at 09:23

I had some troubles with exact same code and just adding quotations 'DokumentRepository' fixed the issue.

@repository(DokumentRepository) public dokumentRepository?: DokumentRepository

Tested on Loopback 4 v 1.21.4

Here's my code.

export class OwnerRepository extends DefaultCrudRepository<Owner, typeof Owner.prototype.ownerId, OwnerRelations> {
  public readonly transactions: HasManyRepositoryFactory<Vehicle, typeof Vehicle.prototype.id>;
  public readonly accounts: HasManyRepositoryFactory<Account, typeof Account.prototype.id>;

  constructor(
    @inject('datasources.mongo') dataSource: MongoDataSource,
    @repository.getter('VehicleRepository') protected vehicleRepositoryGetter: Getter<VehicleRepository>,
    @repository.getter('AccountRepository') protected accountsRepositoryGetter: Getter<AccountRepository>,
    @repository('VehicleRepository') public vehicleRepository: VehicleRepository,
    @repository('AccountRepository') public accountRepository: AccountRepository,
  ) {
    super(Owner, dataSource);
    this.vehicles = this.createHasManyRepositoryFactoryFor('vehicles', vehicleRepositoryGetter);
    this.accounts = this.createHasManyRepositoryFactoryFor('accounts', accountsRepositoryGetter);
  }

Inject a repository into model class?

1 Answers1