v3.0.0

Changelog

• Breaking: Generated mappers no longer have a .container property. This was removed in favor
  of the new MapperContainer.globals container.

  // Instead of this:
  var value = MyClassMapper.container.fromValue(...);
  // Do this:
  var value = MapperContainer.globals.fromValue(...);

  Mapper initialization and usage is now simplified to the following:

  1. When used explicitly (e.g. through MyClassMapper.fromMap or myClass.toMap()) no additional
     initialization is needed.
  2. When used implicitly (through a generic type e.g. MapperContainer.globals.fromMap<MyClass>()) the
     mapper needs to be initialized once before being used with MyClassMapper.ensureInitialized().

• Breaking: Changed internal mapper implementation which causes any custom mapper to break.

  • Removed MapperElementBase class.
  • Added MappingContext being passed to mapper methods.

  See docs on how to use custom mappers in v3.

• Breaking: Removed @MappableLib.createCombinedContainer in favor of @MappableLib.generateInitializerForScope.

  Instead of generating a new container, v3 generates an initialization function for all mappers. Use it early on in your
  application:

  @MappableLib(generateInitializerForScope: InitializerScope.package)
  library main;
  
  import 'main.init.dart';
  
  void main() {
    initializeMappers();
    ...
  }

• Breaking: Improved support and features for .copyWith.

  • Copy-With now supports classes that implement multiple interfaces.
  • Renamed .copyWith.apply() method to .copyWith.$update().
  • Added .copyWith.$merge() and .copyWith.$delta().

  You can now use .copyWith with either an existing instance using .$merge or a map of values using .$delta.

  @MappableClass()
  class A with AMappable {
    A(this.a, this.b);
    
    int? a;
    int? b;
  }
  
  void main() {
    var a = A(1, null);
    
    var c = a.copyWith.$merge(A(null, 2));
    assert(c == A(1, 2));
  
    var d = a.copyWith.$delta({'b': 2});
    assert(d == A(1, 2));
  }

• Breaking: Removed CheckTypesHook in favor of discriminator functions.

  You can now use a custom predicate function as the discriminatorValue of a class. This function can check
  whether the encoded value should be decoded to this subclass and return a boolean.

  @MappableClass()
  abstract class A with AMappable {
    A();
  }
  
  @MappableClass(discriminatorValue: B.checkType)
  class B extends A with BMappable {
    B();
    
    /// checks if [value] should be decoded to [B]
    static bool checkType(value) {
      return value is Map && value['isB'] == true;
    }
  }
  
  @MappableClass(discriminatorValue: C.checkType)
  class C extends A with CMappable {
    C();
    
    /// checks if [value] should be decoded to [C]
    static bool checkType(value) {
      return value is Map && value['isWhat'] == 'C';
    }
  }

• Added support for serializing fields that are not part of the constructor
  when annotated with @MappableField().

• Added EncodingOptions to toValue method.

• Added support for third-party models by using annotated typedefs.

• Added renameMethods to build options.

• Improved performance of generated encoding and decoding methods.

For a detailed migration guide, see this issue.