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@toss/nestjs-aop · npm version

A way to gracefully apply AOP to nestjs
Use nestjs managed instances in any decorators gracefully


English | [한국어](https://github.com/toss/nestjs-aop/blob/v2.x/readme_kr.md)
Table of Contents
  1. Installation
  2. Usage
  3. References
  4. Contributing
  5. License
## Installation ```sh npm install @toss/nestjs-aop pnpm add @toss/nestjs-aop yarn add @toss/nestjs-aop ``` ## Usage #### 1. Import AopModule ```typescript @Module({ imports: [ // ... AopModule, ], }) export class AppModule {} ``` #### 2. Create symbol for LazyDecorator ```typescript export const CACHE_DECORATOR = Symbol('CACHE_DECORATOR'); ``` #### 3. Implement LazyDecorator using nestjs provider `metadata` is the second parameter of createDecorator. ```typescript @Aspect(CACHE_DECORATOR) export class CacheDecorator implements LazyDecorator { constructor(private readonly cache: Cache) {} wrap({ method, metadata: options }: WrapParams) { return (...args: any) => { let cachedValue = this.cache.get(...args); if (!cachedValue) { cachedValue = method(...args); this.cache.set(cachedValue, ...args); } return cachedValue; }; } } ``` #### 4. Add LazyDecoratorImpl to providers of module ```typescript @Module({ providers: [CacheDecorator], }) export class CacheModule {} ``` #### 5. Create decorator that marks metadata of LazyDecorator `options` can be obtained from the warp method and used. ```typescript export const Cache = (options: CacheOptions) => createDecorator(CACHE_DECORATOR, options) ``` #### 6. Use it! ```typescript export class SomeService { @Cache({ // ...options(metadata value) }) some() { // ... } } ``` ## References - https://toss.tech/article/nestjs-custom-decorator - https://youtu.be/VH1GTGIMHQw?t=2973 ## Contributing We welcome contribution from everyone in this project. Read [CONTRIBUTING.md](CONTRIBUTING.md) for detailed contribution guide. ## License MIT © Viva Republica, Inc. See [LICENSE](LICENSE) for details. Toss