Api caching module - either transfer state or js Map

[jimdrury]

Interceptor maybe, with an injection token or using forRoot on the module to define endpoints that they want to cache, then store it in transfer state or a js Map to cache the request

[jimdrury]

@Majies - tagging you as it didnt copy original author over

My only worry about this, if it's an interceptor is that interceptors are a bit scattershot.

I'm wondering whether this would be better served as some form of service?
Something like a TransferHttpClient like:

class TransferHttpClient {

    constructor(
        private http: HttpClient,
        private transferState: TransferState,
    ) {}

    get<T = unknown>(url: string): Observable<T> {

        const key = makeStateKey(http);
        const state = this.transferState.get<T|null>(key, null);

        if (!state) {
            return of(state);
        }

        return this.http
            .get<T>(url)
            .pipe(tap(data => this.transferState.set(data)));
    }

}

class DataAccessor {

    constructor(private http: TransferHttpClient) {
    }

    getData() {
        return this.http.get('http://www.google.com');
    }

}