Build GraphQL schema programmatically

programmatic-schema.groovy

GraphQLObjectType keeperType = newObject()
    .name("keeper")                 // required
    .description("A Zoo Keeper")    // optional
    .field(newFieldDefinition()
        .name("id")
        .description("Keeper ID")
        .type(GraphQLLong)
        .build())
    .field(newFieldDefinition()
        .name("name")
        .description("Keeper Name")
        .type(GraphQLString)
        .build())
    .field(newFieldDefinition()
        .name("animals")
        .description("Animals that the keeper cares for.")
        .type(new GraphQLList(animalType))
        .build())
    .build()

// GraphQLObjectType animalType = .. similar to above

GraphQLObjectType queryType = newObject()
    .name("query")
    .description("Root Query Type")
    .field(newFieldDefinition()
        .name("keepers")
        .description("Overview of all Zoo Keepers")
        .type(new GraphQLList(keeperType))
        // the magic! datafetcher could retrieve this data from anywhere.
        .dataFetcher({ env -> keeperDataFetcher.findAll() })
        .build())
    .field(newFieldDefinition()
        .name("animals")
        .description("Overview of all animals")
        .type(new GraphQLList(animalType))
        .dataFetcher({ env -> animalDataFetcher.findAll() })
        .build())
    .build()

this.schema = GraphQLSchema
    .newSchema()
    .query(queryType)
    .build()