generateForAnnotatedElement method

  1. @override
Future 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
Future generateForAnnotatedElement(
    Element element, ConstantReader annotation, BuildStep buildStep) async {
  var variableElement = element as VariableElement;
  if (!(variableElement.isConst &&
      variableElement.type.toString() == 'String')) {
    throw 'variable: ${variableElement.displayName} must be a constant String';
  }
  String content = await loadAsset(buildStep, annotation);
  return Future.value(
      "const String \$${variableElement.name}Content = r'''${content}''';");
}