withers_extension 0.9.0 copy "withers_extension: ^0.9.0" to clipboard
withers_extension: ^0.9.0 copied to clipboard

Uses class_extensions to generate withers. Withers are a convenient way of constructing copies of immutable objects with altered values.

Description #

Uses class_extensions to generate withers. Withers are a convenient way of constructing copies of immutable objects with altered values.

See also to_string_extension, json_extension

Tutorial #

  1. We need a class to generate withers for. You usually want to generate withers for immutable classes.

    ${PROJECT_ROOT}/lib/model.dart
    import 'package:meta/meta.dart';
       
    @immutable
    class SomeValueClass {
      final String strVal;
      final int intVal;
    }
    
  2. For withers to work you need to add some boiler plate:

    • part 'model.g.dart';
    • annotation @Withers()
    • mixin _$SomeValueClass
    • all args constructor SomeValueClass(this.strVal, this.intVal);
    ${PROJECT_ROOT}/lib/model.dart
    import 'package:meta/meta.dart';
    import 'package:withers_extension_annotations/annotations.dart';
       
    part 'model.g.dart';
       
    @Withers()
    @immutable
    class SomeValueClass with _$SomeValueClass {
      final String strVal;
      final int intVal;
       
      SomeValueClass(this.strVal, this.intVal);
    }
    
  3. Configure code generation. More info at build.

    ${PROJECT_ROOT}/build.yaml
    targets:
      $default:
        builders:
          class_extensions:
            generate_for:
            - lib/*.dart
    
  4. Add dependencies.

    ${PROJECT_ROOT}/pubspec.yaml
    name: example
       
    dependencies:
      withers_extension_annotations: ^0.1.0
       
    dev_dependencies:
      build_runner: ^1.0.0
      withers_extension: 8.0.0
    
  5. Run code generation: pub run build_runner build. File ${PROJECT_ROOT}/lib/model.g.dart should be created.

  6. If everything goes well you should be able to use withers.

    ${PROJECT_ROOT}/bin/main.dart
    import 'package:example/model.dart';
       
    void main() {
      var some = SomeValueClass("some", 0);
      var other = some.withIntVal(1).withStrVal("other");
    }
    
  7. You can also see the example.

1
likes
40
pub points
0%
popularity

Publisher

unverified uploader

Uses class_extensions to generate withers. Withers are a convenient way of constructing copies of immutable objects with altered values.

Repository (GitHub)
View/report issues

License

BSD-3-Clause (LICENSE)

Dependencies

analyzer, build, class_extensions, source_gen, withers_extension_annotations

More

Packages that depend on withers_extension