Package graphql.execution

Class DataFetcherResult<T>

java.lang.Object

graphql.execution.DataFetcherResult<T>

Type Parameters:

T - The type of the data fetched

@PublicApi
public class DataFetcherResult<T>
extends java.lang.Object

An object that can be returned from a DataFetcher that contains both data, local context and errors to be added to the final result. This is a useful when your ``DataFetcher`` retrieves data from multiple sources or from another GraphQL resource, or you want to pass extra context to lower levels.

This also allows you to pass down new local context objects between parent and child fields. If you return a getLocalContext() value then it will be passed down into any child fields via DataFetchingEnvironment.getLocalContext()

You can also have DataFetchers contribute to the ExecutionResult.getExtensions() by returning extensions maps that will be merged together via the ExtensionsBuilder and its ExtensionsMerger in place.

This provides hashCode() and equals(Object) methods that afford comparison with other DataFetcherResult object.s However, to function correctly, this relies on the values provided in the following fields in turn also implementing hashCode()} and equals(Object) as appropriate:

• The data returned in getData().
• The individual errors returned in getErrors().
• The context returned in getLocalContext().
• The keys/values in the getExtensions() Map.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	DataFetcherResult.Builder<T>

Method Summary

Modifier and Type	Method	Description
boolean	equals(java.lang.Object o)
T	getData()
java.util.List<GraphQLError>	getErrors()
java.util.Map<java.lang.Object,java.lang.Object>	getExtensions()	A data fetcher result can supply extension values that will be merged into the result via the ExtensionsBuilder at the end of the operation.
java.lang.Object	getLocalContext()	A data fetcher result can supply a context object for that field that is passed down to child fields
boolean	hasErrors()
int	hashCode()
<R> DataFetcherResult<R>	map(java.util.function.Function<T,R> transformation)	Transforms the data of the current DataFetcherResult using the provided function.
static <T> DataFetcherResult.Builder<T>	newResult()	Creates a new data fetcher result builder
java.lang.String	toString()
DataFetcherResult<T>	transform(java.util.function.Consumer<DataFetcherResult.Builder<T>> builderConsumer)	This helps you transform the current DataFetcherResult into another one by starting a builder with all the current values and allows you to transform it how you want.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Method Detail

getData

public T getData()

Returns:

The data fetched. May be null.

getErrors

public java.util.List<GraphQLError> getErrors()

Returns:

errors encountered when fetching data. This will be non null but possibly empty.

hasErrors

public boolean hasErrors()

Returns:

true if there are any errors present

getLocalContext

public java.lang.Object getLocalContext()

A data fetcher result can supply a context object for that field that is passed down to child fields

Returns:

a local context object

getExtensions

public java.util.Map<java.lang.Object,java.lang.Object> getExtensions()

A data fetcher result can supply extension values that will be merged into the result via the ExtensionsBuilder at the end of the operation.

The ExtensionsMerger in place inside the ExtensionsBuilder will control how these extension values get merged.

Returns:

a map of extension values to be merged

See Also:

ExtensionsBuilder, ExtensionsMerger

transform

public DataFetcherResult<T> transform(java.util.function.Consumer<DataFetcherResult.Builder<T>> builderConsumer)

This helps you transform the current DataFetcherResult into another one by starting a builder with all the current values and allows you to transform it how you want.

Parameters:

builderConsumer - the consumer code that will be given a builder to transform

Returns:

a new instance produced by calling build on that builder

map

public <R> DataFetcherResult<R> map(java.util.function.Function<T,R> transformation)

Transforms the data of the current DataFetcherResult using the provided function. All other values are left unmodified.

Type Parameters:

R - the result type

Parameters:

transformation - the transformation that should be applied to the data

Returns:

a new instance with where the data value has been transformed

equals

public boolean equals(java.lang.Object o)

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

newResult

public static <T> DataFetcherResult.Builder<T> newResult()

Creates a new data fetcher result builder

Type Parameters:

T - the type of the result

Returns:

a new builder