io.smallrye.graphql.execution.datafetcher

Class ReflectionDataFetcher

java.lang.Object

io.smallrye.graphql.execution.datafetcher.ReflectionDataFetcher

All Implemented Interfaces:

graphql.schema.DataFetcher

public class ReflectionDataFetcher
extends Object
implements graphql.schema.DataFetcher

Fetch data using some bean lookup and Reflection

Author:

Phillip Kruger (phillip.kruger@redhat.com)

Constructor Summary

Constructors

Constructor and Description
ReflectionDataFetcher(Operation operation)
ReflectionDataFetcher(Operation operation, Collection<DataFetcherDecorator> decorators) We use this reflection data fetcher on operations (so Queries, Mutations and Source) ParameterClasses: We need an Array of Classes that this operation method needs so we can use reflection to call the method.

Method Summary

Modifier and Type	Method and Description
graphql.execution.DataFetcherResult<Object>	get(graphql.schema.DataFetchingEnvironment dfe) This makes the call on the method.

Methods inherited from class java.lang.Object

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

Constructor Detail

ReflectionDataFetcher

public ReflectionDataFetcher(Operation operation)

ReflectionDataFetcher

public ReflectionDataFetcher(Operation operation,
                             Collection<DataFetcherDecorator> decorators)

We use this reflection data fetcher on operations (so Queries, Mutations and Source) ParameterClasses: We need an Array of Classes that this operation method needs so we can use reflection to call the method. FieldHelper: We might have to transform the data on the way out if there was a Formatting annotation on the method, or return object fields, we can not use normal JsonB to do this because we do not bind a full object, and we support annotation that is not part on JsonB ArgumentHelper: The same as above, except for every parameter on the way in.

Parameters:

operation - the operation

decorators - collection of decorators to invoke before and after fetching the data

Method Detail

get

public graphql.execution.DataFetcherResult<Object> get(graphql.schema.DataFetchingEnvironment dfe)
                                                throws Exception

This makes the call on the method. We do the following: 1) Get the correct instance of the class we want to make the call in using CDI. That allow the developer to still use Scopes in the bean. 2) Get the argument values (if any) from graphql-java and make sue they are in the correct type, and if needed, transformed. 3) Make a call on the method with the correct arguments 4) get the result and if needed transform it before we return it.

Specified by:

get in interface graphql.schema.DataFetcher

Parameters:

dfe - the Data Fetching Environment from graphql-java

Returns:

the result from the call.

Throws:

Exception