generateForAnnotatedElement method
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
generateForAnnotatedElement(
Element element,
ConstantReader annotation,
BuildStep buildStep,
) {
if (element is! ClassElement) {
throw InvalidGenerationSourceError(
'Generator cannot target `${element.name}`.',
todo: 'Remove the EnumGeneration annotation from `${element.name}`.',
element: element);
}
final fields = element.fields
.where((field) => !field.isStatic && !field.isSynthetic)
.map((field) => field.name)
.toList();
// enumの文字列を生成
final enumName = '${element.name}Field';
final enumContent = fields.map((name) => ' $name').join(',\n');
// enum定義を返す
return 'enum $enumName {\n$enumContent\n}';
}