Dataloaders

Nestjs-query integrates a standard implementation of dataloaders. Dataloaders are there to solve the n+1. Sometimes the default implementation can fail, for example when asynchronous custom authorizers are used and the n+1 problem occurs again despite using dataloaders. Then it may be useful to configure the default implementation of the dataloader, for example to pass a custom batch scheduler.

The following example demonstrates how to configure the generated dataloaders. For more information about the dataloader configuration, see the dataloader documentation.

app.module.ts

import { Module } from '@nestjs/common';
import { NestjsQueryGraphQLModule } from '@ptc-org/nestjs-query-graphql';

@Module({
  imports: [
    // ... other imports

    NestjsQueryGraphQLModule.forRoot({
      dataLoader: {
        batchScheduleFn(callback) {
          // Here is an example of a batch scheduler that collects
          // all requests in a time window of 250ms:
          setTimeout(callback, 250);
        },
      },
    }),

    // ... other imports
  ],

  controllers: [],
  providers: [],
})
export class AppModule {}