added data validation

src/app/home/home.component.ts

@@ -91,10 +91,10 @@ export class HomeComponent implements OnInit, OnDestroy {
 
   subscribeWS() {
     this.socket$.subscribe((message) =>  {
-          // console.log(message);
+          console.log(message);
           if (message instanceof Array) {
               message.forEach(element => {
-                this.updateList(element.message);
+                this.updateList(element);
               });
           } else {
               this.updateList(message);
@@ -112,22 +112,53 @@ export class HomeComponent implements OnInit, OnDestroy {
     // console.log(this.serverMessages);
     // console.log(obj);
     const index = this.serverMessages.findIndex((e) => e.location === obj.location);
-    obj.volumeflow = Number(obj.volumeflow.toFixed(2));
-    obj.current = Number(obj.current.toFixed(2));
-    obj.intakepressure = Number(obj.intakepressure.toFixed(2));
-    obj.frequency = Number(obj.frequency.toFixed(2));
+    try {
+      obj.volumeflow = Number(obj.volumeflow.toFixed(2));
+    } catch {
+      console.log('can transform to fixed decimal data missing or not a number');
+    }
+    try {
+      obj.current = Number(obj.current.toFixed(2));
+    } catch {
+      console.log('can transform to fixed decimal data missing or not a number');
+    }
+    try {
+      obj.intakepressure = Number(obj.intakepressure.toFixed(2));
+    } catch {
+      console.log('can transform to fixed decimal data missing or not a number');
+    }
+    try {
+      obj.frequency = Number(obj.frequency.toFixed(2));
+    } catch {
+      console.log('can transform to fixed decimal data missing or not a number');
+    }
+
     if (index === -1) {
         this.serverMessages.push(obj);
 
     } else {
-        this.serverMessages[index] = obj;
+      if (! obj.volumeflow) {
+        obj.volumeflow = this.serverMessages[index].volumeflow;
+      }
+      if (! obj.current) {
+        obj.current = this.serverMessages[index].current;
+      }
+      if (! obj.frequency) {
+        obj.frequency = this.serverMessages[index].frequency;
+      }
+      if (! obj.intakepressure) {
+        obj.intakepressure = this.serverMessages[index].intakepressure;
+      }
+      this.serverMessages[index] = obj;
     }
   }
 
   totalFlowRates() {
     let temp = 0;
     this.serverMessages.forEach(element => {
-      temp += element.volumeflow;
+      if (element.volumeflow) {
+        temp += element.volumeflow;
+      }
     });
     return Number(temp.toFixed(2));
   }