graphql.execution.conversion

Interface ArgumentConverter

All Known Implementing Classes:

ArgumentConversions

@PublicApi
public interface ArgumentConverter

An argument converter is responsible for converting a GraphQLArgument value into some other object representation such as a POJO. This allows later DataFetcher code to assume a specific argument object shape. By default graphql will receive a complex GraphQLInputObjectType as a map of values. You can use this interface to convert this into a type safe POJO say which will then be passed onto DataFetcher code. Uou might use your favourite object mapping framework for conversion such as Jackson or GSON, graphql-java doesnt care, it only cares that you take a basic object and give back the converted one for use further down the execution The inputs you will receive as as follows :

• input object type - a java.util.Map of values
• list of types - a java.util.List of values
• scalar - the underlying java object that scalar coercing function returns, such as String or Integer
• enums - the underlying java object that enum coercing function returns

In general you should not need to convert scalars and enums since they have Coercing functions. This interface is most powerful when you have GraphQLInputObjectType types as argument values.

Method Summary

Modifier and Type	Method and Description
java.lang.Object	convertArgument(ArgumentConverterEnvironment environment) This is called with the object to convert and extra type information about tbe argument being converted.

Method Detail

convertArgument

java.lang.Object convertArgument(ArgumentConverterEnvironment environment)

This is called with the object to convert and extra type information about tbe argument being converted. If the converter cannot or does not want to convert this object then it MUST return ArgumentConverterEnvironment.getValueToBeConverted() so another converter in the chain may have a go.

Parameters:

environment - the conversion environment

Returns:

a new object or ArgumentConverterEnvironment.getValueToBeConverted() if you don't want to convert it