• Angular Services do NOT have to be Singletons – As you probably know, when we add a service to a @NgModule() declaration, it will be a Singelton.
• For example: – export class AdminService { – data = providers: [AdminService, AdminDataService] – })I see a lot of people whose first instinct is to just put all their services in @NgModule() declarations without thinking about the consequences.
• The sole purpose of the service is to share data between child’s components and to provide a couple of helper’s methods.
• So, we just stick it in the component providers and make it a non-singleton service.
• @Component({ – selector: ‘admin-tab’, – providers: [AdminService, AdminDataService] – })The benefit is that when Angular destroyed the component, she will also destroy the service and release the memory that is occupied by him.

@NetanelBasal: I just published “Angular Services do NOT have to be Singletons”

Angular Services do NOT have to be Singletons

As you probably know, when we add a service to a @NgModule() declaration, it will be a Singelton. Meaning, it will live as long as our application lives. For example:

export class AdminService {

data = providers: [AdminService, AdminDataService]

})I see a lot of people whose first instinct is to just put all their services in @NgModule() declarations without thinking about the consequences.

You are not releasing memoryAlthough you probably do not need this memory anymore. Let’s stop for a second and think, do we really need this service to be a wide app singleton?

For example, in our application, we have an admin section where we need to display a big list of data which, of course, is stored in memory.

We don’t need this service to be a singleton. We don’t need a caching layer and no one out of this tab needs data from it.

The sole purpose of the service is to share data between child’s components and to provide a couple of helper’s methods.

So, we just stick it in the component providers and make it a non-singleton service.

@Component({

selector: ‘admin-tab’,

providers: [AdminService, AdminDataService]

})The benefit is that when Angular destroyed the component, she will also destroy the service and release the memory that is occupied by him.

…