Provides an EntityMap that holds a collection of Entity classes with id and Immutable operations Provider
It provides an Entity abstract class with an id property of type Id and an EntityMap class that manages a collection of Entities.
The motivation for this package is to provide a way to operate on Entity collections in an Immutable way.
To add Entity/Id pairs in Dart's Map class in an Immutable way, one must write
/// put entity
final putEntityMap = {...entityMap, id: entity}
/// remove entity
final removeEntityMap = {...entityMap}..removeWhere((id, _) => id == entity.id);In this package, the EntityMap class, which wraps the Map class, can be used to perform Immutable operations on Entity in a readable.
/// put entity
final putEntityMap = entityMap.put(entity);
/// remove entity
final removeEntityMap = entityMap.remove(entity);As an example, we define the User class. The User class is an Entity with String type id and name as properties.
class User implements Entity<String> {
User(this.id, this.name);
@override
final String id;
final String name;
}Declare EntityMap<String, User> to manage a collection of User classes.
Since EntityMap<String, User> is long, define Users as an alias.
typedef Users = EntityMap<String, User>;This completes the preparation. Now we can use the API of the EntityMap class to operate on the User collection Immutably.
final user1 = User("1", "Anya");
final user2 = User("2", "Loid");
final user3 = User("3", "Yor");
// create Empty Users
final users = Users.empty();
// putUsers.entities: [user1]
final putUsers = users.put(user1);
// removeUsers.entities: []
final removeUsers = putUsers.remove(user1);
// putAllUsers.entities: [user1, user2]
final putAllUsers = removeUsers.putAll([user1, user2]);
// findUser: user1
final findUser = putAllUsers.byId(user1.id);
// removeAllUsers: []
final removeAllUsers = putAllUsers.removeAll([user1, user2]);
// whereUsers: [user1]
final whereUsers = putAllUsers.where((e) => e.name == user1.name);
// sorted: [user3, user2, user1]
final spyFamily = Users.fromIterable([user1, user2, user3]);
final sorted = spyFamily.sorted((a, b) => b.id.compareTo(a.id));If desired, a method can be added to the Users class using extension. This can be a very effective way to add User-specific processing.
/// names: (Anya, Loid, Yor)
final spyFamily = Users.fromIterable([user1, user2, user3]);
final names = spyFamily.names;
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