Okay so after spending some 20 hours on this thing . Finally figured it out .
Required a lot of trial and error . Also we most definitely dont have proper/enough documenting for this .
Although my solution answers this question , It answers an extra question as well, which is -> How do I make extensions dynamic for every query ?
Meaning , all 3 (data, errors and extensions) would be dynamic in the response .
My use case - How do I add logs for each query in extensions ?
Answer - (Note - The code below contains lombok annotations)
Step 1 - Creating your Instrumentation Class and the Instrumentation State Class .
//This is the state class .
//State is the first thing created whenever a graphql query is run .
//We will embed our Logs object here .
@Builder
class LogInstrumentationState implements InstrumentationState {
@Getter
@Setter
public LogsDto logsDto;
}
//This is the instrumentation class that will be used to create the graphql object .
//The overridden methods are different stages in the graphql query execution
@Builder
public class LogsInstrumentation extends SimpleInstrumentation {
//First stage in graphql query execution .
//Object for our custom state class object is created here .
@Override
public InstrumentationState createState() {
return LogInstrumentationState.builder().build();
}
//Second Stage in graphql query execution
//Reference of initialized Logs object in the main code flow is passed here .
//This reference is stored in our custom state class's object .
@Override
public ExecutionInput instrumentExecutionInput(ExecutionInput executionInput,
InstrumentationExecutionParameters parameters) {
LogsDto logsDto = (LogsDto) executionInput.getExtensions().get("logs");
LogInstrumentationState logInstrumentationState = parameters.getInstrumentationState();
logInstrumentationState.setLogsDto(logsDto);
return super.instrumentExecutionInput(executionInput, parameters);
}
//This is the last stage in the graphql query execution .
//Logs are taken from the custom container and added into extensions .
@Override
public CompletableFuture<ExecutionResult> instrumentExecutionResult(
ExecutionResult executionResult, InstrumentationExecutionParameters parameters) {
Map<Object, Object> newExtensionMap = getExtensionsMap(executionResult,parameters);
return CompletableFuture.completedFuture(
new ExecutionResultImpl(
executionResult.getData(),
executionResult.getErrors(),
newExtensionMap));
}
//Helper function
public Map<Object, Object> getExtensionsMap(ExecutionResult executionResult, InstrumentationExecutionParameters parameters) {
Map<Object, Object> currentExt = executionResult.getExtensions();
Map<Object, Object> newExtensionMap = new LinkedHashMap<>();
newExtensionMap.putAll(currentExt == null ? Collections.emptyMap() : currentExt);
LogsDto logsDto =
((LogInstrumentationState)parameters.getInstrumentationState()).getLogsDto();
newExtensionMap.put(ControllerConstants.LOGS, logsDto);
return newExtensionMap;
}
}
Step 2 - Creating graphql object -
GraphQL graphQl = GraphQL.newGraphQL(graphqlSchema).instrumentation(LogsInstrumentation.builder().build())
.build();
Step 3 - Creating executing input . This is where you pass the dynamic Log object into the LogsInstrumentation class .
var executionInput = ExecutionInput.newExecutionInput()
.query(...)
.variables(...)
.operationName(...)
.extensions(Map.of("logs",logsDto))
.dataLoaderRegistry(...)
.graphQLContext(graphqlContext).build();
ExecutionResult executionResult = graphQl.execute(executionInput);
Step 4 - This is how you get your extensions after your query has completed .
Map<Object, Object> extensions = executionResult.getExtensions();
LogsDto logsDto = (LogsDto) extensions.get("logs");
My source
