GeezerVison is showing angular.dev — StaticClassProvider • Angular
When true, injector returns an array of instances. This is useful to allow multiple
providers spread across many files to provide configuration information to a common token.
An optional class to instantiate for the token. By default, the provide
class is instantiated.
A list of tokens to be resolved by the injector. The list of values is then
used as arguments to the useClass constructor.
abstract class Shape {
name!: string;
}
class Square extends Shape {
override name = 'square';
}
const injector = Injector.create({
providers: [{provide: Shape, useClass: Square, deps: []}],
});
const shape: Shape = injector.get(Shape);
expect(shape.name).toEqual('square');
expect(shape instanceof Square).toBe(true);
Note that following two providers are not equal:
class Greeting {
salutation = 'Hello';
}
class FormalGreeting extends Greeting {
override salutation = 'Greetings';
}
const injector = Injector.create({
providers: [
{provide: FormalGreeting, useClass: FormalGreeting, deps: []},
{provide: Greeting, useClass: FormalGreeting, deps: []},
],
});
// The injector returns different instances.
// See: {provide: ?, useExisting: ?} if you want the same instance.
expect(injector.get(FormalGreeting)).not.toBe(injector.get(Greeting));
const locale = new InjectionToken<string[]>('locale');
const injector = Injector.create({
providers: [
{provide: locale, multi: true, useValue: 'en'},
{provide: locale, multi: true, useValue: 'sk'},
],
});
const locales: string[] = injector.get(locale);
expect(locales).toEqual(['en', 'sk']);