mirror of
https://github.com/Maks1mS/nestjs-telegraf.git
synced 2024-12-24 15:04:38 +03:00
61 lines
2.0 KiB
Markdown
61 lines
2.0 KiB
Markdown
---
|
|
id: async-configuration
|
|
title: Async configuration
|
|
sidebar_label: Async configuration
|
|
slug: /async-configuration
|
|
---
|
|
|
|
When you need to pass module options asynchronously instead of statically, use the forRootAsync() method. As with most dynamic modules, Nest provides several techniques to deal with async configuration.
|
|
|
|
One technique is to use a factory function:
|
|
|
|
```typescript
|
|
TelegrafModule.forRootAsync({
|
|
useFactory: () => ({
|
|
token: 'TELEGRAM_BOT_TOKEN',
|
|
}),
|
|
});
|
|
```
|
|
|
|
Like other [factory providers](https://docs.nestjs.com/fundamentals/custom-providers#factory-providers-usefactory), our factory function can be async and can inject dependencies through inject.
|
|
|
|
```typescript
|
|
TelegrafModule.forRootAsync({
|
|
imports: [ConfigModule.forFeature(telegrafModuleConfig)],
|
|
useFactory: async (configService: ConfigService) => ({
|
|
token: configService.get<string>('TELEGRAM_BOT_TOKEN'),
|
|
}),
|
|
inject: [ConfigService],
|
|
});
|
|
```
|
|
|
|
Alternatively, you can configure the TelegrafModule using a class instead of a factory, as shown below:
|
|
|
|
```typescript
|
|
TelegrafModule.forRootAsync({
|
|
useClass: TelegrafConfigService,
|
|
});
|
|
```
|
|
|
|
The construction above instantiates `TelegrafConfigService` inside `TelegrafModule`, using it to create the required options object. Note that in this example, the `TelegrafConfigService` has to implement the `TelegrafOptionsFactory` interface, as shown below. The `TelegrafModule` will call the `createTelegrafOptions()` method on the instantiated object of the supplied class.
|
|
|
|
```typescript
|
|
@Injectable()
|
|
class TelegrafConfigService implements TelegrafOptionsFactory {
|
|
createTelegrafOptions(): TelegrafModuleOptions {
|
|
return {
|
|
token: 'TELEGRAM_BOT_TOKEN',
|
|
};
|
|
}
|
|
}
|
|
```
|
|
|
|
If you want to reuse an existing options provider instead of creating a private copy inside the `TelegrafModule`, use the `useExisting` syntax.
|
|
|
|
```typescript
|
|
TelegrafModule.forRootAsync({
|
|
imports: [ConfigModule.forFeature(telegrafModuleConfig)],
|
|
useExisting: ConfigService,
|
|
});
|
|
```
|