Spring4D Manual

DI, Collections, Mapping, Events for Delphi.

1. Dependency Injection

Register & Resolve

Container := TContainer.Create;
Container.RegisterType<IMyInterface, TMyImplementation>.AsSingleton;
MyInterface := Container.Resolve<IMyInterface>;

Lifetime

• AsSingleton - Single shared instance
• AsTransient - New instance each time
• AsScoped - Scoped instance

Constructor Injection

TMyImpl = class(TInterfacedObject, IMyInterface)
  constructor Create(Dep: IOtherInterface);
end;

Container.RegisterType<IMyInterface, TMyImpl>;
Container.RegisterType<IOtherInterface, TOtherImpl>;

2. Collections

Lists

List := TCollections.CreateList<Integer>;
List.Add(1);
List.Add(2);

Dictionaries

Dict := TCollections.CreateDictionary<Integer, string>;
Dict.Add(1, 'One');

Thread-Safe

SafeList := TCollections.CreateThreadSafeList<Integer>;

3. Functional

FilteredList := List.Where(function(V: Integer): Boolean
  begin Result := V > 2; end);

Sum := List.Aggregate(0, function(A, B: Integer): Integer
  begin Result := A + B; end);

4. Lazy Init

LazyValue := Lazy<Integer>.Create(
  function: Integer begin Result := ExpensiveCalc; end);

5. Events

Event := TEvent<TNotifyEvent>.Create;
Event.Add(MyHandler);
Event.Invoke(Sender);

6. Patterns

// Singleton
Container.RegisterType<TMySingleton>.AsSingleton;

// Factory
Container.RegisterType<IMyInterface>(function: IMyInterface
  begin Result := TMyImpl.Create; end);