Why do we use @Injectable() decorator , when we can actually inject . . . In the @Injectable() decorator for the service itself In the @NgModule() decorator for an NgModule In the @Component() decorator for a component The @Injectable() decorator has the providedIn metadata option, where you can specify the provider of the decorated service class with the root injector, or with the injector for a specific NgModule
angular - What does @Injectable mean? - Stack Overflow Injectable() in the service specifies that this service can be injected used in other components In short if service has injectable decorator, other components can use that service by creating reference of service class in the constructor
What is the difference between @Inject and @Injectable in Angular 2 . . . The @Injectable decorator aims to actually set some metadata about which dependencies to inject into the constructor of the associated class It's a class decorator that doesn't require parameters It's a class decorator that doesn't require parameters
When do we need to use @Injectable on our services in Angular2? The first paragraph sounds like the previous @Injectable documentation, while the second paragraph got it right Just keep in mind that it is just recommended that we always add the @Injectable decorator on all our services as we may later decide that we need to add dependency parameters, but forget the add the @Injectable when we do so
angular - Component as Injectable? - Stack Overflow A component is injectable by default @Component() (or @Directive()) includes @Injectable() Don't expect to get a specific instance of a component injected This works for example with constructor(@Host() private parentComponent) where DI lookup is limited to parent injectors up to the injector of the host element
node. js - What is Injectable in NestJS? - Stack Overflow import { Injectable } from '@nestjs common'; const userMock = [{ account: 'dung', password: '12345678' }]; @Injectable() export class UserService { getUser() { return userMock } } I not really understand @Injectable in NestJS Some tutorial tell @Injectable tell the @Controller know it's an install and can use it as a Dependency Injection But
Flutter Injectable: inject multiple instances of generic types via . . . I am using get_it in my flutter project for the dependency injection Now I am trying to do it with injectable to replace my handwritten dependency file with annotations I have the special case, that I have a class which is generic and must be injected 3 times with a different value of T class TestBloc<T> {
ngOnInit not being called when Injectable class is Instantiated I don't know about all the lifecycle hooks, but as for destruction, ngOnDestroy actually get called on Injectable when it's provider is destroyed (for example an Injectable supplied by a component) From the docs : Lifecycle hook that is called when a directive, pipe or service is destroyed
typescript - What is the purpose of providedIn with the Injectable . . . import { Injectable } from '@angular core'; import { UserModule } from ' user module'; @Injectable({ providedIn: UserModule, }) export class UserService { } This method is preferred because it enables Tree-shaking ( Tree shaking is a step in a build process that removes unused code from a code base ) of the service if nothing injects it