add ifPackageListExists to packageservice

projects/common/src/fm/services/package.service.ts

@@ -7,7 +7,8 @@ import {IItem} from '../models/item';
 import {IItemTask} from '../models/itemTask';
 import {HttpClient} from '@angular/common/http';
 import {AppConfig} from '../shared/app.config';
-import {Observable} from 'rxjs';
+import {Observable,iif,of} from 'rxjs';
+import {switchMap} from 'rxjs/operators';
 
 @Injectable({
   providedIn: 'root',
@@ -16,12 +17,13 @@ import {Observable} from 'rxjs';
 export class PackageService {
   private userPackages: { [key: string]: IPackage } = {};
   private packages: { [key: string]: IPackage } = {};
+  private packagesObservable = this.store$.select(appCommonReducer.SelectGetPackages);
 
   constructor(private store$: Store<appCommonReducer.State>, public httpClient: HttpClient, public appConfig: AppConfig) {
     store$.select(appCommonReducer.SelectGetValidUserPackages).subscribe((packages) => {
       this.userPackages = packages;
     });
-    store$.select(appCommonReducer.SelectGetPackages).subscribe((packages) => {
+    this.packagesObservable.subscribe((packages) => {
       this.packages = packages;
     });
   }
@@ -41,6 +43,14 @@ export class PackageService {
   postItemPackageTask(item: IItem, task: IItemTask): Observable<IItemTask> {
     return this.httpClient.post<IItemTask>(`${this.ApiEndpoint()}/api/v1/items/${item.code}/packagetasks`, task);
   }
+
+  ifPackageListExists<Type>(packageList: Array<string>, ifTrue:Observable<Type>,ifFalse:Observable<Type>):Observable<Type> {
+    return this.packagesObservable.pipe(switchMap(packages => 
+        iif(( )=> Object.keys(packages).some(id => packageList.includes(id)),
+            ifTrue,
+            ifFalse) 
+    )); 
+  }
 }
 
 export function getValidPackages(packageMap: IPackages): {[key: string]: IPackage} {