It is possible generate a service with angular cli and add it as a provider in the app.module.ts in a single step or using an special option in the ng g service command?
When a execute:
$ ng g service services/backendApi installing service create src/app/services/backend-api.service.spec.ts create src/app/services/backend-api.service.ts WARNING Service is generated but not provided, it must be provided to be used 
Next to it, (and according to the WARNING message) I usually add it to provider section on app.module.ts using the text editor:
@NgModule({ declarations: [ AppComponent, ... ], imports: [ .... ], providers: [BackendApiService], bootstrap: [AppComponent] }) It is possible to do it with a single step, to automatize this?
10 Answers
Actually, it is possible to provide the service (or guard, since that also needs to be provided) when creating the service.
The command is the following...
ng g s services/backendApi --module=app.module
Edit
It is possible to provide to a feature module, as well, you must give it the path to the module you would like.
ng g s services/backendApi --module=services/services.module
Angular 6+ Singleton Services
The recommended approach for a singleton service for Angular 6 and beyond is :
import { Injectable } from '@angular/core'; @Injectable({ providedIn: 'root', }) export class UserService { } In fact the CLI --module switch doesn't even exist any more for registering a service at the app level because it doesn't need to modify app.module.ts anymore.
This will create the above code, without needing to specify a module.
ng g s services/user So if you don't want your service to be a singleton you must remove the providedIn code yourself - and then add it manually to providers for a component or lazy loaded module. Doesn't look like there is currently a switch to not generate the providedIn: 'root' part so you need to manually remove it.
Specify paths
--app --one one.module.ts --services --two two.module.ts --services Create Service with new folder in module ONE
ng g service one/services/myNewServiceFolderName/serviceOne --module one/one --one one.module.ts // service imported and added to providers. --services --myNewServiceFolderName serviceOne.service.ts serviceOne.service.spec.ts slight change in syntax from the accepted answer for Angular 5 and angular-cli 1.7.0
ng g service backendApi --module=app.module Looks like in Angular v11 and higher, we don't have option "s" anymore:
ng g service services/backendApi or like that:
ng g service services/backendApi --flat --skipTests=true Add a service to the Angular 4 app using Angular CLI
An Angular 2 service is simply a javascript function along with it's associated properties and methods, that can be included (via dependency injection) into Angular 2 components.
To add a new Angular 4 service to the app, use the command ng g service serviceName. On creation of the service, the Angular CLI shows an error:
To solve this, we need to provide the service reference to the src\app\app.module.ts inside providers input of @NgModule method.
Initially, the default code in the service is:
import { Injectable } from '@angular/core'; @Injectable() export class ServiceNameService { constructor() { } } A service has to have a few public methods.
In Angular 5.12 and latest Angular CLI, do
ng generate service my-service -m app.module ng generate service userService //shorthand for creating service ng g s serviceName ** When you fire this command it will automatically registered inside providers array. **
providers: [ UserService ] In Command prompt go to project folder and execute following:
ng g s servicename run the below code in Terminal
makesure You are inside your project folder in terminal
ng g s servicename --module=app.module 
