Display alert if no recipients are selected iOS - ios

Question

I have a page where we select recipients (who are friends) to send an image to. but if no recipients are selected we can still send the message. i want it so that if no recipients are selected we can show a UIAlertView. for me its not working when i try to display an alert please see my code below.
.h
#property (nonatomic, strong) NSArray *friends;
#property (nonatomic, strong) PFRelation *friendsRelation;
#property (nonatomic, strong) NSMutableArray *recipients;
- (IBAction)send:(id)sender;
.m
- (void)viewDidLoad
{
[super viewDidLoad];
self.recipients = [[NSMutableArray alloc] init];
}
- (void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
self.friendsRelation = [[PFUser currentUser] objectForKey:#"friendsRelation"];
PFQuery *query = [self.friendsRelation query];
[query orderByAscending:#"username"];
[query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
if (error) {
NSLog(#"Error %# %#", error, [error userInfo]);
}
else {
self.friends = objects;
[self.tableView reloadData];
}
}];
//display camera modally etc......
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
PFUser *user = [self.friends objectAtIndex:indexPath.row];
cell.textLabel.text = user.username;
if ([self.recipients containsObject:user.objectId]) {
cell.accessoryType = UITableViewCellAccessoryCheckmark;
}
else {
cell.accessoryType = UITableViewCellAccessoryNone;
}
return cell;
}
#pragma mark - Table view delegate
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
[self.tableView deselectRowAtIndexPath:indexPath animated:NO];
UITableViewCell *cell = [self.tableView cellForRowAtIndexPath:indexPath];
PFUser *user = [self.friends objectAtIndex:indexPath.row];
if (cell.accessoryType == UITableViewCellAccessoryNone) {
cell.accessoryType = UITableViewCellAccessoryCheckmark;
[self.recipients addObject:user.objectId];
}
else {
cell.accessoryType = UITableViewCellAccessoryNone;
[self.recipients removeObject:user.objectId];
}
NSLog(#"%#", self.recipients);
}
here is the part where i try to display my alert
- (IBAction)send:(id)sender {
if (!self.recipients) {
UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:#"Sorry" message:#"Select some friends" delegate:self cancelButtonTitle:#"OK" otherButtonTitles:nil];
[alertView show];
} else {
[self uploadMessage];
//we upload the message in method to parse.com
}
}
it does not seem to show for some reason so we can send messages to no one. how can i show the alert view?

Answer 1

Try this. Check objects of recipients is equal to 0 or not.
- (IBAction)send:(id)sender {
if ([self.recipients count]==0) {
UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:#"Sorry" message:#"Select some friends" delegate:self cancelButtonTitle:#"OK" otherButtonTitles:nil];
[alertView show];
} else {
[self uploadMessage];
//we upload the message in method to parse.com
[self.tabBarController setSelectedIndex:1];
}
}

Answer 2

The problem with your code is the condition that you are checking::
if (!self.recipients)
here self.recipients will always give true value as it will look for memory address of this object, which you have assigned to it in your viewDidLoad method.
You have to check for the count of the array in your scenario.