Allows Dart reflection using code generation/builder.

Last update: Oct 30, 2022

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Overview

reflection_factory

reflection_factory allows Dart reflection with an easy approach, even for third-party classes, using code generation portable for all Dart platforms.

Usage

To enable/generate reflection for some class/type, you can use two approaches:

@EnableReflection():

Annotation that indicates that a specific class/type will have reflection.
@ReflectionBridge([User, Profile]):

Annotation that indicates through a bridge class that the types (User and Profile) will have reflection.

@EnableReflection

The annotations @EnableReflection is used above your class/type that you want to have reflection enabled.

File: some_source_file.dart:

import 'package:reflection_factory/reflection_factory.dart';

// Add a reference to the code generated by:
// $> dart run build_runner build
part 'some_source_file.reflection.g.dart';

// Indicates that reflection for class `User` will be generated/enabled:
@EnableReflection()
class User {
  String? email;

  String pass;

  User(this.email, this.pass);

  User.empty() : this(null,'') ;

  bool get hasEmail => email != null;

  bool checkPassword(String pass) {
    return this.pass == pass;
  }
}

void main() {
  var user = User('[email protected]', '123');

  // The generated reflection:
  var userReflection = user.reflection;

  var fieldEmail = userReflection.field('email')!;
  print('email: ${fieldEmail.get()}');

  var methodCheckPassword = userReflection.method('checkPassword')!;

  var passOk1 = methodCheckPassword.invoke(['wrong']); // false
  print('pass("wrong"): $passOk1');

  var passOk2 = methodCheckPassword.invoke(['123']); // true
  print('pass("123"): $passOk2');

  // Using the generated `toJson` extension method:
  print('User JSON:');
  print(user.toJson());

  // Using the generated `toJsonEncoded` extension method:
  print('User JSON encoded:');
  print(user.toJsonEncoded());
  
  // Accessing reflection through class:
  var userReflection2 = User$reflection();

  // Creating an `User` instance from default or empty constructor:
  var user2 = userReflection2.createInstance()!;

  user2.email = '[email protected]';
  user2.pass = 'abc';

  print('User 2 JSON:');
  print(user2.toJson());
  
}

OUTPUT:

email: [email protected]
pass("wrong"): false
pass("123"): true
User JSON:
{email: [email protected], hasEmail: true, pass: 123}
User JSON encoded:
{"email":"[email protected]","hasEmail":true,"pass":"123"}
User 2 JSON:
{email: [email protected], hasEmail: true, pass: abc}

@ReflectionBridge

The annotations @ReflectionBridge is used above a bridge class, and indicates that third-party types will have reflection generated.

File: some_source_file.dart:

import 'package:reflection_factory/reflection_factory.dart';

// Class `User` is from a third-party package:
import 'package:some_api/user.dart';

// Add a reference to the code generated by:
// $> dart run build_runner build
part 'some_source_file.reflection.g.dart';

// Indicates that reflection for class `User` will be generated/enabled
// through a bridge class:
@ReflectionBridge([User])
class UserReflectionBridge {}

void main() {
  var user = User('[email protected]', '123');

  // The generated reflection through bridge class:
  var userReflection = UserReflectionBridge().reflection(user);

  var fieldEmail = userReflection.field('email')!;
  print('email: ${fieldEmail.get()}');

  print('User JSON encoded:');
  print(user.toJsonEncoded());
}

OUTPUT:

email: [email protected]
User JSON encoded:
{"email":"[email protected]","pass":"123","hasEmail":true}

Dependencies

You need to add 2 dependencies in your project:

File: pubspec.yaml

dependencies:
  reflection_factory: ^1.0.0

dev_dependencies:
  build_runner: ^2.1.1

Building/Generating Code

To generate the reflection code just run build_runner in your Dart project:

$> dart run build_runner build

Source

The official source code is hosted @ GitHub:

https://github.com/gmpassos/reflection_factory

Features and bugs

Please file feature requests and bugs at the issue tracker.

Contribution

Any help from the open-source community is always welcome and needed:

Found an issue?
- Please fill a bug report with details.
Wish a feature?
- Open a feature request with use cases.
Are you using and liking the project?
- Promote the project: create an article, do a post or make a donation.
Are you a developer?
- Fix a bug and send a pull request.
- Implement a new feature.
- Improve the Unit Tests.
Have you already helped in any way?
- Many thanks from me, the contributors and everybody that uses this project!

If you donate 1 hour of your time, you can contribute a lot, because others will do the same, just be part and start with your 1 hour.

Author

Graciliano M. Passos: gmpassos@GitHub.

License

Apache License - Version 2.0

Comments

v1.2.13
Json:

Add parameter TypeInfo as an alternative to the parameter Type.

Improve collections casting.

TypeInfo:

Added constructors: TypeInfo.fromListType, TypeInfo.fromSetType, TypeInfo.fromMapType.

Added toListType, toSetType, toIterableType, toMapValueType and toMapKeyType.

Added castList, castSet, castIterable and castMap.
opened by gmpassos 2

Upgrade analyzer dependency for compatibility with newer packages

Trying to use reflection factory with other packages causes conflict in getting dependencies (e.g. flutter_data: ^1.4.4)

flutter pub get

Because reflection_factory <1.0.24 depends on analyzer ^2.1.0 and reflection_factory >=1.0.24 <1.1.1 depends on analyzer ^3.3.1, reflection_factory <1.1.1 requires analyzer ^2.1.0 or ^3.3.1.
And because reflection_factory >=1.1.1 depends on analyzer ^3.4.1, every version of reflection_factory requires analyzer ^2.1.0 or >=3.3.1 <4.0.0.
Because no versions of flutter_data match >1.4.4 <2.0.0 and flutter_data 1.4.4 depends on analyzer ^4.1.0, flutter_data ^1.4.4 requires analyzer ^4.1.0.
Thus, flutter_data ^1.4.4 is incompatible with reflection_factory.
So, because scout_core depends on both flutter_data ^1.4.4 and reflection_factory any, version solving failed.
pub get failed (1; So, because scout_core depends on both flutter_data ^1.4.4 and reflection_factory any, version solving failed.)

Is upgrading the dependency possible?

opened by alguintu 2

v1.2.8
FunctionReflection.methodInvocationFromMap and FunctionReflection.methodInvocation:

Better handling of unresolved parameters values. Attempts to resolve 2 times, to allow entities references through cache.

Reflection:

castList, castSet, castIterable, castMap, castCollection:

Added parameter nullable.
opened by gmpassos 1
v1.2.7
TypeInfo:

Added T generic type.

Added callCasted to pass the T to a Function<T>().

Improved internal representation og arguments.

ReflectionBuilder:

Declare reflected types using TypeInfo<T> generics.
opened by gmpassos 1
Not an issue, so much as some questions
I saw your reference to reflection_factory in a thread about the dart:mirror module. I have two questions:

can reflection_factory be used as a replacement for json_serializable?

if yes, will "dart compile exe" fail if I use your reflection_factory the way it does when using json_serializable?

if no, (I doubt this) could importing reflection_factory, cause json_serializable to no longer cause this compilation issue?

You can see my use case in a comment below yours.

Thanks
question
opened by labaxter 1
v1.0.20
Added TypeInfo to perform type checking and handle other Type operations needed for reflection use.

Improved TypeReflection for Function types.

Fixed constructors with nullable named parameters.

Fixed constructors with required named parameters.

Fixed fields/parameters with Function typedef alias.
opened by gmpassos 1
[Question] Intercepting to Method invocation
Following up on the discussion -> https://github.com/google/reflectable.dart/issues/301#issuecomment-1338130765

I am wondering how I can use reflection_factory to accomplish this. Are you able to provide some code examples?

Client Code:

@Component() class MyWidget extends StatelessWidget { @override State<MyWidget> createState() => _MyWidgetState(); } class _MyWidgetState extends State<MyWidget> { @override void dispose() { <-------<< // I want to do something when before this method is called. } }
opened by dinbtechit 7