How use data loaders ?

[rullyalves]

Hi, first thanks for great work, how use data loaders with this library ?

[phillip-kruger]

Can you provide some more details on what you want ?

[x80486]

This really depends on how the models are structured, but for any complex application, GraphQL's nested structure will result in multiple calls to the same data sources. Facebook came up with something called DataLoader to batch and cache these calls. DataLoader is first and foremost a data loading mechanism, and its cache only serves the purpose of not repeatedly loading the same data in the context of a single request to the application.

I think the ask is for SmallRye GraphQL to add support to it as well.

For instance, Netflix's DGS Framework integrated that somehow, and they can do things like:

@DgsDataLoader(name = "nameTheDataLoader")
public class ModelDataLoader implements BatchLoader<String, Model> {
  @Override
  public CompletionStage<List<Model>> load(Collection<String> keys) {
    return CompletableFuture.supplyAsync(() -> service.getModelByAGivenCriteriaFrom(keys));
  }
}

...then in the resolvers:

DataLoader<String, Model> dl = dgsDataFetchingEnvironment.getDataLoader("nameTheDataLoader");