improvment adding an option to generate a empty() method

[me-zo]

Hi i've been using this plugin for a while and one thing bothered me so i thought id check if adding it is possible, a common method we use is the empty() function when using data classes is it possible to add that into the plugin so it generates it along with the copyWith() option.

[dinbtechit]

Can you provide some code examples?

[me-zo]

yes sure, basically the output will look like this.

class OtherModel {
  const OtherModel();
  static const OtherModel empty = OtherModel();
}

class Model {
  final int someInt;
  final String someString;
  final OtherModel someOtherModel;

  const Model({
    required this.someInt,
    required this.someString,
    required this.someOtherModel,
  });

  static const Model empty = Model(
    someInt: 0,
    someString: "",
    someOtherModel: OtherModel.empty,
  );
}

[me-zo]

I've changed it to be a const var so it can be used by other constructors

[dinbtechit]

oh, you mean a default value for each member variable. I am not sure how far this is practical. What if the SomeOtherModel class was inside a 3rd party library. It would not have the method empty() in it.

I think we could do something like this but it will have compile errors. Until you provide a default value for each member variable.

const Model.defaultValue({
  this.someInt = /*Provide Default Value*/,
  this.someString = /*Provide Default Value*/,
  this.someOtherModel = /*Provide Default Value*/
});

[me-zo]

yeah I understand your concern however this is only useful in data classes where Model and SomeOtherModel are either Dtos, Models, or Entities. so in the case one of them is in a package, the user will need to handle it. but in most cases these will be passed as parameters in the UI layer or inside ViewModels. so having them without a any parameters and as constants is essential. as for the name, default is a better name than empty for sure.

[dinbtechit]

I just realized you can't use default as it is a reserved keyword. I also simplified the code in my answer. But I guess you can create a named argument constructor and pass in the default values.

const Model.defaultValue({
  this.someInt = /*Provide Default Value*/,
  this.someString = /*Provide Default Value*/,
  this.someOtherModel = /*Provide Default Value*/
});

This is one of the use cases that can be solved using the upcoming feature in Dart 3 Macros/static metaprogramming.