TableView not reloading when data is inserted into source from different source - ios

Question

I have a ChatViewController where I send and receive messages and store the messages as a NSMutableDictionary in an NSArray.
NSMutableArray *messages; //in header file
- (void)addMessage:(NSString *)receivedMessage :(NSString *) sender
{
[self reloadDataInTableView:receivedMessage :sender];
}
- (void)reloadDataInTableView:(NSString *)message :(NSString*)sender
{
NSLog(#"Text: %# Sender: %#", message, sender);
NSMutableDictionary *m = [[NSMutableDictionary alloc] init];
[m setObject:message forKey:#"msg"];
[m setObject:sender forKey:#"sender"];
[messages addObject:m];
[self.tView reloadData];
NSLog(#"Number of rows: %d", [messages count]);
}
When I am calling 'addMessage' from AppDelegate, both the strings are passed but it cannot add it to the 'messages' because the 'Number of rows' always is zero. But when I am storing it from that class itself then the messages are getting stored and row count increases.
As a result, it only shows the messages from the ChatViewController but not the messages sent from the AppDelegate. I hope I was able to explain the problem properly.
Here is the cellForRowAtIndexPath function:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
NSMutableDictionary *s = (NSMutableDictionary *) [messages objectAtIndex:indexPath.row];
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
//cell = [[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier:CellIdentifier];
}
cell.textLabel.text = [s objectForKey:#"msg"];
cell.detailTextLabel.text = [s objectForKey:#"sender"];
cell.accessoryType = UITableViewCellAccessoryNone;
cell.userInteractionEnabled = NO;
return cell;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return [messages count];
}
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
return 1;
}
Yes, I have initialized the messages array in viewDidLoad. But the problem is when I am trying to insert into the messages array from the AppDelegate the count is not increasing. In fact, it always shows zero. But when I insert from the ViewController itself, it maintains the count. Here is the AppDelegate code:
- (void)xmppStream:(XMPPStream *)sender didReceiveMessage:(XMPPMessage *)message
{
if ([message isChatMessageWithBody])
{
XMPPUserCoreDataStorageObject *user = [xmppRosterStorage userForJID:[message from]
xmppStream:xmppStream
managedObjectContext:[self managedObjectContext_roster]];
NSString *messageBody = [[message elementForName:#"body"] stringValue];
NSString *displayName = [user jidStr];
if ([[UIApplication sharedApplication] applicationState] == UIApplicationStateActive)
{
ChatViewController *cvc = [[ChatViewController alloc] init];
[cvc reloadDataInTableView:messageBody :displayName];
}
else
{
// We are not active, so use a local notification instead
UILocalNotification *localNotification = [[UILocalNotification alloc] init];
localNotification.alertAction = #"Ok";
localNotification.alertBody = [NSString stringWithFormat:#"From: %#\n\n%#",displayName,messageBody];
[[UIApplication sharedApplication] presentLocalNotificationNow:localNotification];
}
}
}

Answer 1

When you do
ChatViewController *cvc = [[ChatViewController alloc] init];
[cvc reloadDataInTableView:messageBody :displayName];
in your app delegate, you are instantiating a new ChatViewController. Even if the messages array was initialised in the init method (which it isn't, as you said it is initialised in the viewDidLoad method), this new instance of the ChatViewController is discarded at the end of your xmppStream:didReceiveMessage: method and is definitely not the same that is showing on screen.
You need to keep a reference to the proper instance of ChatViewController in your app delegate and use that instead of instantiating a new one...
If you want some more specific advice on how to approach this problem, you'll need to give us more detail about your whole project's architecture (using storyboard? is there a navigation controller? tab controller? how does the chatviewcontroller relate to other view controllers? etc. etc.).

Answer 2

You need
messages = [[NSMutableArray alloc] init];
in viewdidload

Answer 3

Try this:
- (void)reloadDataInTableView:(NSString *)message :(NSString*)sender
{
NSLog(#"Text: %# Sender: %#", message, sender);
NSMutableDictionary *m = [[NSMutableDictionary alloc] init];
[m setObject:message forKey:#"msg"];
[m setObject:sender forKey:#"sender"];
if (!messages)
{
messages = [[NSMutableArray alloc] init];
}
[messages addObject:m];
[self.tView reloadData];
NSLog(#"Number of rows: %d", [messages count]);
}