What is providers in App Module TS?
A provider is an instruction to the Dependency Injection system on how to obtain a value for a dependency. Most of the time, these dependencies are services that you create and provide.
What is Angular provider?
A provider is an object declared to Angular so that it can be injected in the constructor of your components, directives and other classes instantiated by Angular.
What is injectable ({ ProvidedIn root })?
The @Injectable() decorator specifies that Angular can use this class in the DI system. The metadata, providedIn: ‘root’ , means that the HeroService is visible throughout the application.
What is injection token?
What is an Injection Token. The Injection Token allows creating token that allows the injection of values that don’t have a runtime representation. But instead of using a hardcoded string, we create the Injection Token by creating a new instance of the InjectionToken class.
What are services in Angular 8?
An Angular service is plain Typescript class having one or more methods (functionality) along with @Injectable decorator. It enables the normal Typescript class to be used as service in Angular application.
What are view providers?
The View provider is an instance and method provider that creates new classes based on instances of other classes. You can use the View provider to take properties from different source classes, different namespaces, or different computers and combine the properties as a single class.
What is AngularJS provider?
A provider is an object with a $get() method. The injector calls the $get method to create a new instance of a service. The Provider can have additional methods which would allow for configuration of the provider. AngularJS uses $provide to register new providers.
What is providedIn in @injectable?
The providedIn allow us to specify how Angular should provide the dependency in the service class itself instead of in the Angular Module. It also helps to make the service tree shakable i.e. remove the service from the final bundle if the app does not use it. ProvidedIn root.
Should you use providedIn root?
providedIn: ‘root’ is the easiest and most efficient way to provide services since Angular 6: The service will be available application wide as a singleton with no need to add it to a module’s providers array (like Angular <= 5).
What is provider token Angular?
When you configure an injector with a provider, you are associating that provider with a dependency injection token, or DI token. The injector lets Angular create a map of any internal dependencies. The DI token acts as a key to that map. The dependency value is an instance, and the class type serves as a lookup key.