Examples with DataFetcher graphql.schema.DataFetcher used on opensource projects

Example 6 with DataFetcher

use of graphql.schema.DataFetcher in project graphql-java by graphql-java.

the class BatchingExamples method starWarsExample.

void starWarsExample() {
    // a batch loader function that will be called with N or more keys for batch loading
    BatchLoader<String, Object> characterBatchLoader = new BatchLoader<String, Object>() {

        @Override
        public CompletionStage<List<Object>> load(List<String> keys) {
            // 
            return CompletableFuture.supplyAsync(() -> getCharacterDataViaBatchHTTPApi(keys));
        }
    };
    // a data loader for characters that points to the character batch loader
    DataLoader<String, Object> characterDataLoader = new DataLoader<>(characterBatchLoader);
    // 
    // use this data loader in the data fetchers associated with characters and put them into
    // the graphql schema (not shown)
    // 
    DataFetcher heroDataFetcher = new DataFetcher() {

        @Override
        public Object get(DataFetchingEnvironment environment) {
            // R2D2
            return characterDataLoader.load("2001");
        }
    };
    DataFetcher friendsDataFetcher = new DataFetcher() {

        @Override
        public Object get(DataFetchingEnvironment environment) {
            StarWarsCharacter starWarsCharacter = environment.getSource();
            List<String> friendIds = starWarsCharacter.getFriendIds();
            return characterDataLoader.loadMany(friendIds);
        }
    };
    // 
    // DataLoaderRegistry is a place to register all data loaders in that needs to be dispatched together
    // in this case there is 1 but you can have many
    // 
    DataLoaderRegistry registry = new DataLoaderRegistry();
    registry.register("character", characterDataLoader);
    // 
    // this instrumentation implementation will dispatched all the dataloaders
    // as each level fo the graphql query is executed and hence make batched objects
    // available to the query and the associated DataFetchers
    // 
    DataLoaderDispatcherInstrumentation dispatcherInstrumentation = new DataLoaderDispatcherInstrumentation(registry);
    // 
    // now build your graphql object and execute queries on it.
    // the data loader will be invoked via the data fetchers on the
    // schema fields
    // 
    GraphQL graphQL = GraphQL.newGraphQL(buildSchema()).instrumentation(dispatcherInstrumentation).build();
}

Example 7 with DataFetcher

use of graphql.schema.DataFetcher in project graphql-java by graphql-java.

the class ConcernsExamples method contextHelper.

private void contextHelper() {
    // 
    // this could be code that authorises the user in some way and sets up enough context
    // that can be used later inside data fetchers allowing them
    // to do their job
    // 
    UserContext contextForUser = YourGraphqlContextBuilder.getContextForUser(getCurrentUser());
    ExecutionInput executionInput = ExecutionInput.newExecutionInput().context(contextForUser).build();
    ExecutionResult executionResult = graphQL.execute(executionInput);
    // ...
    // 
    // later you are able to use this context object when a data fetcher is invoked
    // 
    DataFetcher dataFetcher = new DataFetcher() {

        @Override
        public Object get(DataFetchingEnvironment environment) {
            UserContext userCtx = environment.getContext();
            Long businessObjId = environment.getArgument("businessObjId");
            return invokeBusinessLayerMethod(userCtx, businessObjId);
        }
    };
}

Example 8 with DataFetcher

use of graphql.schema.DataFetcher in project graphql-java by graphql-java.

the class MappingExamples method productsDataFetcher.

void productsDataFetcher() {
    DataFetcher productsDataFetcher = new DataFetcher() {

        @Override
        public Object get(DataFetchingEnvironment env) {
            String matchArg = env.getArgument("match");
            List<ProductInfo> productInfo = getMatchingProducts(matchArg);
            List<ProductCostInfo> productCostInfo = getProductCosts(productInfo);
            List<ProductTaxInfo> productTaxInfo = getProductTax(productInfo);
            return mapDataTogether(productInfo, productCostInfo, productTaxInfo);
        }
    };
}

Example 9 with DataFetcher

use of graphql.schema.DataFetcher in project graphql-java by graphql-java.

the class ReadmeExamples method dataFetching.

void dataFetching() {
    DataFetcher<Foo> fooDataFetcher = new DataFetcher<Foo>() {

        @Override
        public Foo get(DataFetchingEnvironment environment) {
            // environment.getSource() is the value of the surrounding
            // object. In this case described by objectType
            // Perhaps getting from a DB or whatever
            Foo value = perhapsFromDatabase();
            return value;
        }
    };
    GraphQLObjectType objectType = newObject().name("ObjectType").field(newFieldDefinition().name("foo").type(GraphQLString).dataFetcher(fooDataFetcher)).build();
}

Example 10 with DataFetcher

use of graphql.schema.DataFetcher in project ontrack by nemerosa.

the class GQLRootQueryBuilds method buildFetcher.

private DataFetcher buildFetcher() {
    return environment -> {
        Integer id = environment.getArgument("id");
        Optional<String> oProject = GraphqlUtils.getStringArgument(environment, PROJECT_ARGUMENT);
        Optional<String> oBranch = GraphqlUtils.getStringArgument(environment, BRANCH_ARGUMENT);
        Object branchFilter = environment.getArgument(BUILD_BRANCH_FILTER_ARGUMENT);
        Object projectFilter = environment.getArgument(BUILD_PROJECT_FILTER_ARGUMENT);
        // Per ID
        if (id != null) {
            checkArgList(environment, "id");
            return Collections.singletonList(structureService.getBuild(ID.of(id)));
        } else // Per project
        if (oProject.isPresent()) {
            // ... and branch
            if (oBranch.isPresent()) {
                // Gets the branch
                Branch branch = structureService.findBranchByName(oProject.get(), oBranch.get()).orElseThrow(() -> new BranchNotFoundException(oProject.get(), oBranch.get()));
                // Configurable branch filter
                BuildFilterProviderData<?> filter = inputBuildStandardFilter.convert(branchFilter);
                // Runs the filter
                return filter.filterBranchBuilds(branch);
            } else // Project only
            {
                // Gets the project
                Project project = structureService.findProjectByName(oProject.get()).orElseThrow(() -> new ProjectNotFoundException(oProject.get()));
                // Build search form as argument
                BuildSearchForm form = inputBuildSearchForm.convert(projectFilter);
                return structureService.buildSearch(project.getId(), form);
            }
        } else // Branch filter only - not accepted
        if (branchFilter != null) {
            throw new IllegalStateException(String.format("%s must be used together with %s", BUILD_BRANCH_FILTER_ARGUMENT, BRANCH_ARGUMENT));
        } else // Project filter only - not accepted
        if (projectFilter != null) {
            throw new IllegalStateException(String.format("%s must be used together with %s", BUILD_PROJECT_FILTER_ARGUMENT, PROJECT_ARGUMENT));
        } else // None
        {
            return Collections.emptyList();
        }
    };
}