Class DirectivesExamples

src/test/groovy/readme/DirectivesExamples.java:29–199

import java.util.Map;

@SuppressWarnings({"Convert2Lambda", "unused", "ClassCanBeStatic"})
public class DirectivesExamples {

    static class AuthorisationCtx {
        boolean hasRole(String roleName) {
            return true;
        }

        static AuthorisationCtx obtain() {
            return null;
        }
    }

    class AuthorisationDirective implements SchemaDirectiveWiring {

        @Override
        public GraphQLFieldDefinition onField(SchemaDirectiveWiringEnvironment<GraphQLFieldDefinition> environment) {
            String targetAuthRole = (String) environment.getAppliedDirective().getArgument("role").getArgumentValue().getValue();

            //
            // build a data fetcher that first checks authorisation roles before then calling the original data fetcher
            //
            DataFetcher originalDataFetcher = environment.getFieldDataFetcher();
            DataFetcher authDataFetcher = new DataFetcher() {
                @Override
                public Object get(DataFetchingEnvironment dataFetchingEnvironment) throws Exception {
                    AuthorisationCtx authContext = dataFetchingEnvironment.getGraphQlContext().get("authContext");

                    if (authContext.hasRole(targetAuthRole)) {
                        return originalDataFetcher.get(dataFetchingEnvironment);
                    } else {
                        return null;
                    }
                }
            };
            //
            // now change the field definition to have the new authorising data fetcher
            return environment.setFieldDataFetcher(authDataFetcher);
        }
    }

    void authWiring() {

        //
        // we wire this into the runtime by directive name
        //
        RuntimeWiring.newRuntimeWiring()
                .directive("auth", new AuthorisationDirective())
                .build();

    }

    String query = "";

    void contextWiring() {

        AuthorisationCtx authCtx = AuthorisationCtx.obtain();