added preloading guard for search results

src/app/+search-page/search-page-preloader.guard.ts

@@ -0,0 +1,27 @@
+import { Injectable } from '@angular/core';
+import { ActivatedRouteSnapshot, CanActivate, Resolve, RouterStateSnapshot } from '@angular/router';
+import { Observable } from 'rxjs/Observable';
+import { RemoteData } from '../core/data/remote-data';
+import { getSucceededRemoteData } from '../core/shared/operators';
+import { ItemDataService } from '../core/data/item-data.service';
+import { Item } from '../core/shared/item.model';
+import { SearchService } from './search-service/search.service';
+import { SearchConfigurationService } from './search-service/search-configuration.service';
+import { map } from 'rxjs/operators';
+
+@Injectable()
+export class SearchPagePreloader implements CanActivate {
+  constructor(private searchService: SearchService, private configService: SearchConfigurationService) {
+  }
+
+  canActivate(route: ActivatedRouteSnapshot, state: RouterStateSnapshot): Observable<boolean> | Promise<boolean> | boolean {
+    const searchResults$ = this.configService.paginatedSearchOptions.flatMap((options) =>
+      this.searchService.search(options)
+    );
+    route.data.results = searchResults$;
+    return searchResults$.pipe(
+      getSucceededRemoteData(),
+      map(() => true),
+    ).catch(() => Observable.of(false))
+  }
+}

src/app/+search-page/search-page-routing.module.ts

@@ -2,12 +2,22 @@ import { NgModule } from '@angular/core';
 import { RouterModule } from '@angular/router';
 
 import { SearchPageComponent } from './search-page.component';
+import { SearchPagePreloader } from './search-page-preloader.guard';
 
 @NgModule({
   imports: [
     RouterModule.forChild([
-      { path: '', component: SearchPageComponent, data: { title: 'search.title' } }
+      {
+        path: '',
+        component: SearchPageComponent,
+        data: { title: 'search.title' },
+        canActivate: [SearchPagePreloader]
+      }
     ])
+  ],
+  providers: [
+    SearchPagePreloader
   ]
 })
-export class SearchPageRoutingModule { }
+export class SearchPageRoutingModule {
+}