Mastering TypeScript 3 - Third Edition

Class resolution

As an alternative to the enum implementation, we could also use special purpose classes. This is best illustrated by looking at a code sample, as follows:

interface ISystemSettings { } 
class IISystemSettings { } 
 
interface IMailService { } 
class IIMailService { } 
 
class ServiceLocatorGeneric { 
    public static register<T>( 
        interfaceName: {new(): T;}, instance: any) {} 
    public static resolve<T>( 
        interfaceName: {new() : T}) {} 
} 
 
ServiceLocatorGeneric.register(IISystemSettings, {}); 
 
ServiceLocatorGeneric.resolve(IISystemSettings); 

Here, we start with an interface named ISystemSettings, which is the interface that we wish to use with our service locator. We then define a class named IISystemSettings that has no functions or properties, ...