[DSC-287] invalidate root endpoint cache when redirected to 500 page in order to check every time the rest server availability

src/app/core/data/root-data.service.ts

@@ -106,5 +106,12 @@ export class RootDataService {
   findAllByHref(href: string | Observable<string>, findListOptions: FindListOptions = {}, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<Root>[]): Observable<RemoteData<PaginatedList<Root>>> {
     return this.dataService.findAllByHref(href, findListOptions, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
   }
+
+  /**
+   * Set to sale the root endpoint cache hit
+   */
+  invalidateRootCache() {
+    this.requestService.setStaleByHrefSubstring('server/api');
+  }
 }
 /* tslint:enable:max-classes-per-file */

src/app/core/server-check/server-check.guard.ts

@@ -32,6 +32,7 @@ export class ServerCheckGuard implements CanActivate {
       map((res: RemoteData<any>) => res.hasSucceeded),
       tap((hasSucceeded: boolean) => {
         if (!hasSucceeded) {
+          this.rootDataService.invalidateRootCache();
           this.router.navigateByUrl(getPageInternalServerErrorRoute());
         }
       }),