generateForAnnotatedElement method

@override dynamic generateForAnnotatedElement(Element element, ConstantReader annotation, 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
dynamic generateForAnnotatedElement(
    Element element, ConstantReader annotation, BuildStep buildStep) {
  final config = readConfig(annotation, element);
  final typeList = config['forClasses'] as List<DartObject>;
  final build = <Spec>[];
  final classesToGenerate =
      typeList.map((type) => type.toTypeValue()!.element!).toList();
  for (final clazz in classesToGenerate) {
    if (clazz is! ClassElement) {
      throw InvalidGenerationSourceError(
          '${element.displayName} is not a class and a generator cannot be created for this',
          element: element,
          todo: 'Only add classes to the generatable classes');
    }
    build.add(buildClass(clazz));
  }

  build.add(buildInit(classesToGenerate));

  final lib = generateLibrary(build, classesToGenerate);
  final emitter = DartEmitter(
    allocator: Allocator.simplePrefixing(),
    orderDirectives: true,
    useNullSafetySyntax: true,
  );
  return '${lib.accept(emitter)}';
}