Swift Language Design Patterns - Creational Singleton
Example
Singletons are a frequently used design pattern which consists of a single instance of a class that is shared throughout a program.
In the following example, we create a static property that holds an instance of the Foo class. Remember that a static property is shared between all objects of a class and can't be overwritten by subclassing.
public class Foo
{
static let shared = Foo()
// Used for preventing the class from being instantiated directly
private init() {}
func doSomething()
{
print("Do something")
}
}
Usage:
Foo.shared.doSomething()
Be sure to remember the private initializer:
This makes sure your singletons are truly unique and prevents outside objects from creating their own instances of your class through virtue of access control. Since all objects come with a default public initializer in Swift, you need to override your init and make it private. KrakenDev
