added InstanceLinkPayload model to handle the instanceChanged events

Author: janniclas

client/src/app/model/models/instanceLink.ts

@@ -1,3 +1,4 @@
+import { Instance } from './instance';
 
 export interface InstanceLink {
     idFrom: number;
@@ -15,3 +16,13 @@ export interface InstanceLink {
         Failed: 'Failed' as LinkStateEnum
     };
 
+    export interface InstanceLinkPayload {
+        link: InstanceLink;
+        instanceFrom: Instance;
+        instanceTo: Instance;
+    }
+
+    export function objIsLink(obj: any): obj is InstanceLink {
+        return obj.idFrom !== undefined && typeof obj.idFrom === 'number' && obj.idTo !== undefined && typeof obj.idTo === 'number' &&
+                obj.linkState !== undefined && obj.linkState in LinkStateEnum;
+    }