Examples with BatchLoader org.dataloader.BatchLoader used on opensource projects

Example 1 with BatchLoader

use of org.dataloader.BatchLoader in project graphql-java by graphql-java.

the class HttpMain method buildDataLoaderRegistry.

private DataLoaderRegistry buildDataLoaderRegistry() {
    BatchLoader<String, Object> friendsBatchLoader = keys -> CompletableFuture.supplyAsync(() -> loadCharactersViaHTTP(keys));
    DataLoader<String, Object> friendsDataLoader = new DataLoader<>(friendsBatchLoader);
    DataLoaderRegistry dataLoaderRegistry = new DataLoaderRegistry();
    // 
    // we make sure our dataloader is in the registry
    dataLoaderRegistry.register("friends", friendsDataLoader);
    return dataLoaderRegistry;
}

Example 2 with BatchLoader

use of org.dataloader.BatchLoader 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();
}