generateForAnnotatedElement method

  1. @override
Iterable<String> generateForAnnotatedElement(
  1. Element element,
  2. ConstantReader annotation,
  3. BuildStep buildStep
)

Implement to return source code to generate for element.

This method is invoked based on finding elements annotated with an instance of T. The annotation is provided as a ConstantReader.

Supported return values include a single String or multiple String instances within an Iterable or Stream. It is also valid to return a Future of String, Iterable, or Stream.

Implementations should return null when no content is generated. Empty or whitespace-only String instances are also ignored.

Implementation

@override
Iterable<String> generateForAnnotatedElement(
  Element element,
  ConstantReader annotation,
  BuildStep buildStep,
) {
  if (!element.library!.isNonNullableByDefault) {
    throw InvalidGenerationSourceError(
      'Generator cannot target libraries that have not been migrated to '
      'null-safety.',
      element: element,
    );
  }

  if (element is! ClassElement || element is EnumElement) {
    throw InvalidGenerationSourceError(
      '`@JsonSerializable` can only be used on classes.',
      element: element,
    );
  }

  final helper = GeneratorHelper(_settings, element, annotation);
  return helper.generate();
}