1

Is it possible to find(probably with the mirror API) all classes(in my project) with some metadata annotation?

Example: 

import 'baz.dart'; //more tagged classes

@Tag(#foo)
class A{

}
@Tag(#foo)
class B{

}

void main() {
 List<ClassMirror> li = getClassMirrorsByTag(#foo);
}
JAre
  • 4,666
  • 3
  • 27
  • 45

1 Answers1

2

I have found the answer:

getClassMirrorsByTag.dart 

library impl;
@MirrorsUsed(metaTargets: Tag)
import 'dart:mirrors';

class Tag {
  final Symbol name;
  const Tag(this.name);
}
List<ClassMirror> getClassMirrorsByTag(Symbol name) {
  List<ClassMirror> res = new List<ClassMirror>();
  MirrorSystem ms = currentMirrorSystem();
  ms.libraries.forEach((u, lm) {
    lm.declarations.forEach((s, dm) {
      dm.metadata.forEach((im) {
        if ((im.reflectee is Tag) && im.reflectee.name == name) {
          res.add(dm);
        }
      });
    });
  });
  return res;
}

extra.dart 

library extra;
import 'getClassMirrorsByTag.dart';

@Tag(#foo)
class C {}

main.dart 

library  main;
import 'getClassMirrorsByTag.dart';
import 'extra.dart';
@Tag(#foo)
class A{}
@Tag(#baz)
class B{}


void main() {
  print(getClassMirrorsByTag(#foo));
}

output:

[ClassMirror on 'A', ClassMirror on 'C']

JAre
  • 4,666
  • 3
  • 27
  • 45
  • the List res = new List(); worked fine with classes, but not with functions, do you have an idea if I want to use the same with functions, what shall I use instead of this line, thanks – Hasan A Yousef Nov 09 '14 at 08:30
  • @HasanAYousef Function mirrors have type `MethodMirror` and classes `ClassMirror` If you replace it with `List res = new List();` then you will have mixed type collection of mirrors. – JAre Nov 09 '14 at 11:10
  • thanks, can you help with this http://stackoverflow.com/questions/26826521/executing-bundle-of-functions-by-their-metadata-tag-in-dart-lang – Hasan A Yousef Nov 09 '14 at 11:19