Add gradient service

projects/common/src/fm/components/package-exists/package-exists.directive.ts

@@ -0,0 +1,61 @@
+import {AfterViewInit, Directive, Input, OnDestroy, TemplateRef, ViewContainerRef} from '@angular/core';
+import {Subscription} from 'rxjs';
+import {PackageService} from '../../services/package.service';
+import * as appCommonReducer from '../../reducers/app-common.reducer';
+import {Store} from '@ngrx/store';
+
+@Directive({
+  selector: '[fmPackageExists]',
+})
+export class PackageExistsDirective implements OnDestroy, AfterViewInit {
+
+  @Input()
+  set fmPackageExists(packageIdentifier: string) {
+    this.packageIdentifier = packageIdentifier;
+    this.updateView();
+  }
+
+  @Input()
+  set fmPackageExistsThen(thenTemplate: TemplateRef<any>) {
+    this.thenTemplate = thenTemplate;
+    this.updateView();
+  }
+
+  @Input()
+  set fmPackageExistsElse(thenTemplate: TemplateRef<any>) {
+    this.elseTemplate = thenTemplate;
+    this.updateView();
+  }
+
+  private packageIdentifier: string;
+  private thenTemplate: TemplateRef<any>;
+  private elseTemplate: TemplateRef<any>;
+  private packSub: Subscription;
+
+  constructor(private hostTemplateRef: TemplateRef<any>, private viewContainerRef: ViewContainerRef,
+              private store: Store<appCommonReducer.State>, private packageService: PackageService) {
+    this.thenTemplate = hostTemplateRef;
+    this.packSub = this.store.select(appCommonReducer.SelectGetPackages).subscribe((_) => {
+      this.updateView();
+    });
+  }
+
+  ngAfterViewInit() {
+    this.updateView();
+  }
+
+  updateView() {
+    this.viewContainerRef.clear();
+    if (this.packageService.packageExists(this.packageIdentifier)) {
+      this.viewContainerRef.createEmbeddedView(this.thenTemplate);
+    } else if (this.elseTemplate) {
+      this.viewContainerRef.createEmbeddedView(this.elseTemplate);
+    }
+  }
+
+  ngOnDestroy() {
+    if (this.packSub) {
+      this.packSub.unsubscribe();
+    }
+  }
+}