made the message page counter to only increment if the current requested page was not empty

chatto/src/main/javascript/ts/src/model/ChatModel.ts

@@ -67,18 +67,18 @@ export class ChatModel implements Subject {
     }
 
     public async getMessages(contactName: string, passphrase: string, lastMessageTime: string | null): Promise<ChatMessageViewModel[]> {
-        if(this._messagePageMap.get(contactName) == null)
+        if (this._messagePageMap.get(contactName) == null)
             this._messagePageMap.set(contactName, 0);
-        else {
-            log.debug('page number before = ' + this._messagePageMap.get(contactName)!)
-            this._messagePageMap.set(contactName, this._messagePageMap.get(contactName)! + 1);
-            log.debug('page number after = ' + this._messagePageMap.get(contactName)!)
-        }
-        const pageNumber =  this._messagePageMap.get(contactName)
+        // else {
+        //     log.debug('page number before = ' + this._messagePageMap.get(contactName)!)
+        //     this._messagePageMap.set(contactName, this._messagePageMap.get(contactName)! + 1);
+        //     log.debug('page number after = ' + this._messagePageMap.get(contactName)!)
+        // }
+        const pageNumber = this._messagePageMap.get(contactName)
         const cVMs = await ChatModelHelper.getMessages(contactName, passphrase, pageNumber!, lastMessageTime, this);
         if (cVMs != null) {
             log.info('Subject: My state has just changed')
-            
+
             // this._messagesMap.set(userName, cVMs);
             const existingMessages = this.getStoredUserMessages(contactName);
             log.debug(existingMessages);
@@ -101,6 +101,11 @@ export class ChatModel implements Subject {
         else {
             log.error('Messages were null');
         }
+        if (cVMs.length != 0) {
+            // log.debug('page number before = ' + this._messagePageMap.get(contactName)!)
+            this._messagePageMap.set(contactName, this._messagePageMap.get(contactName)! + 1);
+            // log.debug('page number after = ' + this._messagePageMap.get(contactName)!)
+        }
 
         return cVMs;
     }