What is Providedln?
The providedIn property is used to specify the root injector or module where a service or module should be provided. It essentially tells Angular where the dependency should be available and how it should be instantiated. This property is typically used in the @Injectable() decorator for services or in the module metadata for modules.
When you create a service in Angular, you can specify its providedIn property to control its visibility and scope. There are three main options for the providedIn property:
- Root: If you set providedIn: ‘root’, the service will be available throughout the entire application, and only one instance of the service will be created and shared across all components and services that inject it.
- Module: If you set providedIn: SomeModule, the service will be available only within the specified module and its child modules. A new instance of the service will be created for each child module that injects it.
- Component: If you don’t specify the providedIn property or set it to null, the service will be available only within the component that creates it. A new instance of the service will be created for each component that injects it.
Purpose of ProvidedIn in Angular
Angular’s dependency injection system is a powerful mechanism that helps manage dependencies between components, services, and other parts of the application. One important aspect of this system is the providedIn property, which determines the scope and visibility of a service or module. In this article, we’ll explore the purpose of providedIn in Angular and how it relates to the overall dependency injection mechanism.
Table of Content
- What is dependency injection?
- What is Providedln?
- Features of Providedln
- Example of ProvidedIn in Angular
- Conclusion