/// <summary>
/// DEFINITION
/// - Software design pattern in which an object, called the subject, maintains a list of its dependents, called observers,
/// and notifies them automatically of any state changes, ussually calling one of their methods.
/// USAGE
/// -When you need many other objects to recieve an update when another objecy changes
/// -Publisher Subject sends many data to Observers
/// -Observers Subscribers take the data they want and use it.
/// ADVANTAGES
/// -Loose coupling
/// -Publisher doen't need to know anything about the Subscribers
/// DISADVANTAGES
/// -Publisher may send updates that don't matter to the subscriber
/// </summary>
private static void executeObserverDesignPattern()
{
Console.ForegroundColor = ConsoleColor.DarkGreen;
Console.WriteLine("OBSERVER PATTERN \n");
Console.ForegroundColor = ConsoleColor.White;
IPublisher publisher = new Subject()
{
imbStock = 8000,
mcsoftStock = 6500,
nasStock = 5760
};
ISubscriber dikeledi = new Observer(publisher);
ISubscriber papa = new Observer(publisher);
Console.WriteLine("\n Published to {0} observers \n", publisher.publish());
((Subject)publisher).imbStock = 1000.02;
ISubscriber madillo = new Observer(publisher);
ISubscriber nozy = new Observer(publisher);
publisher.unregisterObserver(dikeledi);
Console.WriteLine("\n Published to {0} observers \n", publisher.publish());
Console.WriteLine("------------------- \n");
}
static void Main( string[] args )
{
/*
* Factory Method Pattern
*/
Creator c = new Creator( );
IProduct product;
for ( int i = 1; i <= 12; i++ )
{
product = c.FactoryMethod(i);
Console.WriteLine("Product " + product.ShipFrom( ));
}
/*
* Factory Method Ends
*/
/*
* Observer pattern
*/
Subject subject = new Subject( );
Observer.Observer observer1 = new Observer.Observer("Observer 1");
subject.Subscribe(observer1);
Observer.Observer observer2 = new Observer.Observer("observer 2");
subject.Subscribe(observer2);
subject.Inventory++;
subject.Unsubscribe(observer2);
subject.Subscribe(new Observer.Observer("observer 3"));
subject.Inventory++;
}
public CurrentConditionsDisplay(Subject weatherData)
{
this.weatherData = weatherData;
weatherData.RegisterObserver(this);
}
public Observer(string name, Subject subject)
{
_name = name;
_subject = subject;
}
public void Update(Subject subject)
{
Console.WriteLine("name is {0} price is {1}", Name, subject.Price);
}
