# Register service

Before injecting a service into vue component, you should register it into your app.

```typescript
// Your services.

import { Injectable } from '@vert/core'

@Injectable()
class HttpService {
}

@Injectable()
class BookshelfService {
  constructor (
    private httpSrv: HttpService
  ) {}
}

@Injectable()
class UserService {
  constructor (
    private httpSrv: HttpService
  ) {}
}

export {
  BookshelfService,
  UserService
}
```

Registration:

```typescript
import { App } from '@vert/core'

// You have these two services and you should register theme for your app.
import { BookshelfService, HttpService, UserService } from './services'

// Registration.
// You will get different instances of these services in every single initialization.
App.addTransient(BookshelfService, HttpService, UserService)

// You will get the same instance of these every single service.
App.addSingleton(BookshelfService, HttpService, UserService)

// For more detail about this behavior, please check "05.use-injector.md".
```

## API

```typescript
/**
 * App is the basic unit for a project.
 *
 * @class App
 */
class App {
  /**
   * Register target as a singleton provider in global.
   *
   * @static
   * @template T
   * @param {TConstructor[]} Providers
   */
  static addSingleton (...Providers: TConstructor[]): typeof App

  /**
   * Register target as a transient provider in global.
   *
   * @static
   * @template T
   * @param {TConstructor[]} Providers
   */
  static addTransient (...Providers: TConstructor[]): typeof App
}
```