cache-observable

I created this decorator for cashing requests in my angular services.

Installation

npm i --save cache-observable

Usage

Need add @CacheObservable(ms) before a function that return ConnectableObservable (angular http.get() or Observable.ajax()), where ms is cache time in milliseconds.

Example

// book.service.ts

// ...
import CacheObservable from 'cache-observable';

@Injectable()
export class BookService {
  private path: string = '/books';

  constructor(private api: apiService) {
  }

  @CacheObservable(60 * 1000) // 1 min cache
  getBook(id: string): Observable<Book> {
    return this.api.get(`${this.path}/${id}`);
  }

  // ...
}

How it work

1. Call a function with @CacheObservable() decorator;
2. The Decorator lib check, if a storage have the observable entry then return it;
3. If the storage haven't a entry of a called function, then the Decorator lib create new entry in the storage;
4. The new entry observable has been chained with next functions:

• publishReplay(1, ms) // publish one item for ms milliseconds
• refCount() // check all subscribers
• take(1) // take one

5. Return the entry.

License

MIT