DGS Framework: how to provide additional data to the data fetcher? - spring-boot

Question

I have a example DgsQuery:
#DgsQuery
public List<Sensor> sensors(DgsDataFetchingEnvironment dfe) {
SensorType sensorType = SensorType.newBuilder()
.id(UUID.randomUUID().toString())
.build();
Sensor sensor = new Sensor();
sensor.setId(UUID.randomUUID().toString());
sensor.setName("foo");
sensor.setSensorType(sensorType);
return Arrays.asList(sensor);
}
And a data fetcher:
#DgsData(parentType = DgsConstants.SENSOR.TYPE_NAME, field = DgsConstants.SENSOR.SensorType)
public CompletableFuture<SensorType> sensorType(DgsDataFetchingEnvironment dfe) {
Sensor sensor = dfe.getSource();
UUID sensorTypeId = UUID.fromString(sensor.getSensorType().getId());
// fetch sensorType by ID from DB, map to generated class and return
LOGGER.info("Would now fetch sensorType with ID {} via RPC or whatever you want ;)", sensorTypeId);
return null;
}
In the dataFetcher I need to be able to access some additional data / objects that are initialized in the #DgsQuery method. How can I do this?
Example usecase:
In the #DgsQuery there is a Entity that has been loaded from the database, I need to pass this entity to the data fetcher.
Currently I have only access to the Sensor object via
Sensor sensor = dfe.getSource();
but none of some further data that might be already loaded.

Answer 1

Found it out:
#DgsQuery
public DataFetcherResult<List<Sensor>> sensors(DgsDataFetchingEnvironment dfe) {
SensorType sensorType = SensorType.newBuilder()
.id(UUID.randomUUID().toString())
.build();
Sensor sensor = new Sensor();
sensor.setId(UUID.randomUUID().toString());
sensor.setName("foo");
sensor.setSensorType(sensorType);
return DataFetcherResult.<List<Sensor>>newResult()
.data(Arrays.asList(sensor))
.localContext("foo")
.build();
}
and in the data fetcher:
Object localContext = dfe.getLocalContext(); ( --> "foo")