Poll webservice url for 200 OK on frontend load

src/app/dashboard/dashboard.component.html

@@ -7,7 +7,7 @@
       <app-messages (newMessageEvent)="scrollMessagesToBottom()"></app-messages>
     </div>
     <div class="tfw-web tao-grid-top-left"
-         [ngClass]="{'deploy-blur': deploying || polling}">
+         [ngClass]="{'deploy-blur': deploying || (polling | async)}">
         <div *ngIf="iframeUrl | async" class="iframe-container">
           <div *ngIf="showUrlBar | async" class="urlbar-container">
             <button class="refresh btn btn-sm rounded-circle" (click)="reloadIframe()">&#8635;</button>

src/app/dashboard/dashboard.component.ts

@@ -1,6 +1,6 @@
 import { Component, OnDestroy, OnInit, ChangeDetectorRef, ElementRef, ViewChild } from '@angular/core';
 import { DeploymentNotificationService } from '../services/deployment-notification.service';
-import { Subscription } from 'rxjs';
+import { Subscription, BehaviorSubject } from 'rxjs';
 import { WebSocketService } from '../services/websocket.service';
 import { WebSocketMessage } from '../message-types/websocket-message';
 import { DashboardConfigService } from '../services/config.service';
@@ -14,7 +14,7 @@ import { delay, retryWhen, tap } from 'rxjs/operators';
 })
 export class DashboardComponent implements OnInit, OnDestroy {
   deploying = false;
-  polling = false;
+  polling = new BehaviorSubject<boolean>(false);
   deploymentNotificationSubscription: Subscription;
   @ViewChild('webiframe', {static: false}) webiframe: ElementRef;
   @ViewChild('tfwmessages', {static: false}) messages: ElementRef;
@@ -42,12 +42,18 @@ export class DashboardComponent implements OnInit, OnDestroy {
   ngOnInit() {
     this.webSocketService.connect();
     this.configService.init();
+    this.hideIframeUntilResponseOk();
     this.subscribeResizeOnLayoutChange();
     this.initCommandHandling();
     this.initDeploymentNotifications();
     this.sendReady();
   }
 
+  hideIframeUntilResponseOk() {
+    // TODO: hide iframe and show it after this whole deal...
+    this.reloadIframeWhenResponseOk();
+  }
+
   subscribeResizeOnLayoutChange() {
     this.configService.layout.subscribe(() => this.emitResizeEvent());
   }
@@ -64,10 +70,7 @@ export class DashboardComponent implements OnInit, OnDestroy {
       (deploying) => {
         this.deploying = deploying;
         if (!deploying && this.configService.reloadIframeOnDeploy.value) {
-          if (this.polling) {
-            this.iframeReloadSubscription.unsubscribe();
-          }
-          this.pollingServerForIframeReload();
+          this.reloadIframeWhenResponseOk();
         }
       });
   }
@@ -142,8 +145,11 @@ export class DashboardComponent implements OnInit, OnDestroy {
     this.webiframe.nativeElement.contentWindow.frames.location.href = this.urlbar.nativeElement.value;
   }
 
-  pollingServerForIframeReload() {
-    this.polling = true;
+  reloadIframeWhenResponseOk() {
+    if (this.polling.value) {
+      this.iframeReloadSubscription.unsubscribe();
+    }
+    this.polling.next(true);
     this.iframeReloadSubscription = this.http.get(this.actualIframeUrl, {observe: 'response'}).pipe(
       retryWhen(errors =>
         errors.pipe(
@@ -151,15 +157,11 @@ export class DashboardComponent implements OnInit, OnDestroy {
             response => {
               if (response.status === 200) {
                 this.iframeReloadSubscription.unsubscribe();
-                this.polling = false;
+                this.polling.next(false);
                 this.reloadIframe();
-              }
-            }
-          ),
+          }}),
           delay(1000)
-        )
-      )
-    ).subscribe();
+    ))).subscribe();
   }
 
   ngOnDestroy() {