Function getInitialStream

packages/common/http/src/resource.ts:251–271

(req: HttpRequest<unknown> | undefined)

    const originMap = injector.get(HTTP_TRANSFER_CACHE_ORIGIN_MAP, null, {optional: true});

    const getInitialStream = (req: HttpRequest<unknown> | undefined) => {
      if (cacheOptions && transferState && req) {
        const cachedResponse = retrieveStateFromCache(req, cacheOptions, transferState, originMap);
        if (cachedResponse) {
          try {
            const body = cachedResponse.body as TRaw;
            const parsed = options?.parse ? options.parse(body) : (body as unknown as TResult);
            return signal({value: parsed});
          } catch (e) {
            if (typeof ngDevMode === 'undefined' || ngDevMode) {
              console.warn(
                `Angular detected an error while parsing the cached response for the httpResource at \`${req.url}\`. ` +
                  `The resource will fall back to its default value and try again asynchronously.`,
                e,
              );
            }
          }
        }
      }
      return undefined;
    };

    return new HttpResourceImpl(
      injector,