Package org.forum.server.specific_code

Class DataFetchersDelegateMemberImpl

java.lang.Object

org.forum.server.specific_code.DataFetchersDelegateMemberImpl

All Implemented Interfaces:

DataFetchersDelegateMember

@Component
public class DataFetchersDelegateMemberImpl
extends Object
implements DataFetchersDelegateMember

Field Summary

Fields

Modifier and Type	Field	Description
protected org.slf4j.Logger	logger	The logger for this instance

Constructor Summary

Constructors

Constructor	Description
DataFetchersDelegateMemberImpl()

Method Summary

Modifier and Type	Method	Description
List<Member>	batchLoader(List<Long> keys, org.dataloader.BatchLoaderEnvironment env)	This method loads a list of ${dataFetcher.field.name}, based on the list of id to be fetched.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.forum.server.graphql.util.DataFetchersDelegateMember

unorderedReturnBatchLoader

Field Details

logger

protected org.slf4j.Logger logger

The logger for this instance

Constructor Details

DataFetchersDelegateMemberImpl

public DataFetchersDelegateMemberImpl()

Method Details

batchLoader

public List<Member> batchLoader(List<Long> keys,
 org.dataloader.BatchLoaderEnvironment env)

Description copied from interface: DataFetchersDelegateMember

This method loads a list of ${dataFetcher.field.name}, based on the list of id to be fetched. This method is used by graphql-java java-dataloader to highly optimize the number of requests to the server, when recursing down through the object associations.
You can find more information on this page: graphql-java batching
Important notes:

• The list returned by this method must be sorted in the exact same order as the given keys list. If values are missing (no value for a given key), then the returned list must contain a null value at this key's position.
• One of batchLoader or unorderedReturnBatchLoader must be overriden in the data fetcher implementation. If not, then a NullPointerException will be thrown at runtime, with a proper error message.
• If your data storage implementation makes it complex to return values in the same order as the keys list, then it's easier to override unorderedReturnBatchLoader, and let the default implementation of batchLoader order the values

Specified by:

batchLoader in interface DataFetchersDelegateMember

Parameters:

keys - A list of ID's id, for which the matching objects must be returned

env - The Data Loader environment

Returns:

A list of IDs