im_model 1.0.1 im_model: ^1.0.1 copied to clipboard
Annotation for immutable model to generate `copyWith` and == (equal) operator.
import 'package:im_model/im_model.dart';
part 'example.g.dart';
/// Generic type => No need to forward it to the mixin.
/// Inverted ignore flags on class => superseeded by fields
/// [id] is not part of `copyWith`.
/// Only [id] is part of equality.
@ImModel(ignoreEqual: true, ignoreCopy: true)
class Parent<T> with _$ParentMixin {
@ImField(ignoreEqual: false)
final String id;
@ImField(ignoreCopy: false)
final T? aValue;
const Parent(this.id, this.aValue);
}
/// [collection] class member is immutable (you can't use add, remove, ...).
/// [id] is not part of `copyWith`.
/// Only [id] and [collection] are part of equality.
@ImModel()
class Child<T> extends Parent<T> with _$ChildMixin {
final ImList<int> collection;
const Child(super.id, super.aValue, {required this.collection});
}
/// Usage of named constructor to make copies.
/// [copyWith] is not available on this model.
@ImModel(copyConstructor: 'named', ignoreCopy: true)
class Child2<T> extends Child<T> with _$Child2Mixin {
final bool foo;
const Child2.named(
super.id,
super.aValue,
this.foo, {
super.collection = const ImList.empty(),
});
}
void main() {
var obj1 = Child('a', 0, collection: [1].immut);
var obj2 = Child('a', 0, collection: ImList([1]));
print(obj1 == obj2 ? '\u2705 equal!' : '\u274C Not equal');
// obj1.collection.add(2);
// 'add' is deprecated and shouldn't be used. This collection is immutable and will throw exception at runtime.
// So now that we have a clear view in our source code, it's time to fix this!
obj1 = obj1.copyWith(collection: obj1.collection.mut..add(2));
print(obj1 == obj2 ? '\u274C equal!' : '\u2705 Not equal');
// Two things to notice here:
// - we used `mut` getter to mutate the initial collection for shorter syntax. This is a shortcut (forward method) for `List.of`.
// - we didn't had to wrap again the collection to be immutable, this is done in generated code.
// obj1.copyWith(id: 'b');
// The named parameter 'id' isn't defined.
}