DGS custom directive example

[Dgsuser]

Hello Team,

I was looking for dgs Java custom directive sample not the kotlin in the documents but couldn’t able to get information. Could you please provide me links that could be useful. Am trying to implement null filtering directive for my app.

thanks

[srinivasankavitha]

Seems like we are missing documentation for implementing a custom directive. We will add that. In the meantime, you could try something like this:

/**
 *  An `@DgsDirective` example that replaces a string pattern "abc" with "xxx"
 */
@DgsDirective
public class TestDirective implements SchemaDirectiveWiring {
     @Override
     public GraphQLFieldDefinition onField(SchemaDirectiveWiringEnvironment<GraphQLFieldDefinition> env) {
         GraphQLFieldDefinition field = env.getElement();
         GraphQLFieldsContainer parentType = env.getFieldsContainer();

        DataFetcher<?> originalDataFetcher = env.getCodeRegistry().getDataFetcher(parentType, field);
         DataFetcher<?> dataFetcher = DataFetcherFactories.wrapDataFetcher(originalDataFetcher, ((dfe, value) -> {
                 if (value instanceof String) return ((String) value).replace("abc", "xxx");
                 else return value;
             }));
        // set the data fetcher
        env.getCodeRegistry().dataFetcher(parentType, field, dataFetcher);
        return field;
     }
}

[srinivasankavitha]

#891