Can I use a graphQL client to communicate to a graphql server class in the same application?

Question

I am currently creating a POC. We have a proxy lambda linked up to an API gateway. This Lambda access some data and returns films. These items are very large, so we would like to give customers the ability to filter which attributes they get from the items. We would like to do this using graphql. I am also using quarkus and java following this tutorial. https://quarkus.io/guides/smallrye-graphql

I was thinking that by using graphql I could make a resource like

@GraphQLApi
public class FilmResource {

    @Inject
    GalaxyService service;

    @Query("allFilms")
    @Description("Get all Films from a galaxy far far away")
    public List<Film> getAllFilms() {
        return service.getAllFilms();
    }

    @Query
    @Description("Get a Films from a galaxy far far away")
    public Film getFilm(@Name("filmId") int id) {
        return service.getFilm(id);
    }
}

An aws proxy lambda accepts a type of APIGatewayProxyRequestEvent which has a String body. I was hoping I could wrap FilmResource.java in a graphql client and directly apply the body of an APIGatewayProxyEvent to the Film Resource. This would look something like this

@Named("test")
public class TestLambda implements RequestHandler<APIGatewayProxyRequestEvent, APIGatewayProxyResponseEvent> {
    
    @Inject
    FilmResource resource;
    
    @Override
    public APIGatewayProxyResponseEvent handleRequest(APIGatewayProxyRequestEvent awsLambdaEvent, Context context) {
            DynamicGraphQLClient client = DynamicGraphQLClientBuilder.newBuilder().client(resource).build();
            JsonObject data = client.executeSync(awsLambdaEvent.getBody()).getData();
            return new APIGatewayProxyResponseEvent().withBody(data.toString()).withStatusCode(200);
    }
}

So Ideally, the customer would be able to pass the below query to the lambda, and it would receive the correct response.

query allFilms {
  allFilms {
    title
    releaseDate
  }
}

However, it seems like all the clients only work with remote graphql servers. Is there a client that can wrap an internal graphql server class? Source: https://quarkus.io/guides/smallrye-graphql-client

score 0 · Answer 1 · answered Jul 07 '22 at 05:56

There's no way to specifically have the client run over some kind of 'local' transport, but you should still be able to use the HTTP transport even though the target is inside the same JVM. You just need to configure the client to run against an appropriate URL, that could be something like

quarkus.smallrye-graphql-client.MY-CLIENT-KEY.url=http://127.0.0.1:${quarkus.http.port:8080}/graphql

And inject a dynamic client instance using

@Inject
@GraphQLClient("MY-CLIENT-KEY")
DynamicGraphQLClient client;

Can I use a graphQL client to communicate to a graphql server class in the same application?

1 Answers1