get current server values when iPhone launches

[gbenna]

I have an app which I am building using the MQTT_Client_Framework. I and log onto my server, and subscribe to my topics and even get any updated data when new data is published to the server. However I would like to be able to subscribe and get the existing topic values when the app is launched. Right now the only time I get values is when they are updated on the server by another client. I am building the app on an iPhone 11 Pro running IOS 14.2. I used Cocoapods to install the Frameworks. My Broker(server) is Adafruit.com. They say they are not a Broker but a Client. There is not an issue with the code per say, I just want to be able to get the values when I launch the app. Here is my code in the app's ViewController

#import "ViewController.h"
#import <MQTTClient/MQTTClient.h>
@interface ViewController ()
@property (weak, nonatomic) IBOutlet UIImageView *batteryValueLabel;
@property (strong, nonatomic) IBOutlet UIImageView *tempValueLabel;
@property (strong, nonatomic) IBOutlet UILabel *temperatureValueLabel;
@property (weak, nonatomic) IBOutlet UILabel *levelValueLabel;
@property (weak, nonatomic) IBOutlet UILabel *tripValueLabel;
@property (weak, nonatomic) IBOutlet UILabel *dateValueLabel;
@property(nonatomic, strong, readwrite) NSArray *certificates;
@property(nonatomic, weak) IBOutlet UIButton *Fill;

-(IBAction)Turnon:(id)sender;
@end
NSString *trip = @"0";
int trigger =1;
int B = 50;
int T = 90;
MQTTSession *session;
@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.tempValueLabel.frame = CGRectMake(20, 250-(T+45),65, T+45);
    _batteryValueLabel.frame = CGRectMake(114, 287, B*1.7, 63);
    NSString* myNewString = [NSString stringWithFormat:@"%d", T];
    self.temperatureValueLabel.text = myNewString;
    MQTTCFSocketTransport *transport = [[MQTTCFSocketTransport alloc] init];
    transport.host = @"io.adafruit.com";
    transport.port = 1883;

    session = [[MQTTSession alloc] init];
    session.userName = @"xxxxxxxx";
    session.password = @"xxxxxxxxxxxxxxxxxxxxxxx";
    session.transport = transport;
    session.delegate = self;
    [session connectWithConnectHandler:^(NSError *error) {

        if(!error){
            [session subscribeToTopic:@"xxxxxxx/feeds/+" atLevel:1 subscribeHandler:^(NSError *error, NSArray *gQoss){

        if (error) {
            NSLog(@"Subscription failed %@", error.localizedDescription);
        } else {
            NSLog(@"Subscription sucessfull! Granted Qos: %@", gQoss);

           //I GET TO HERE FINE  JUST NEED TO KNOW WHAT TO PUT HERE TO GET THE CURRENT VALUES ON SERVER 
        }
    }];
            }
        else {NSLog(@"[connectWithConnectHandler]Error Connect %@", error.localizedDescription);}
    }];
 }
//THIS WORKS FINE TO GET UPDATED VALUES
- (void)newMessage:(MQTTSession *)session
              data:(NSData *)data
           onTopic:(NSString *)topic
               qos:(MQTTQosLevel)qos
          retained:(BOOL)retained
               mid:(unsigned int)mid {
    NSString *dataString = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
    NSLog(@"topic: %@", topic);
    NSLog(@"data:%@", dataString);
    if ([topic isEqualToString:@"xxxxxxx/feeds/temperature"]){
        T = [dataString intValue];
        self.temperatureValueLabel.text = dataString;
        self.tempValueLabel.frame = CGRectMake(20, 250-(T+45),65, T+45);
        if (T <= 69) {
            _tempValueLabel.image = [UIImage imageNamed:@"dk blue rectangle.png"];
        }
        else if ((69< B)&& (B <= 90)) {
            _tempValueLabel.image = [UIImage imageNamed:@"blue rectangle.png"];
        }
        else if (B > 90) {
            _tempValueLabel.image = [UIImage imageNamed:@"red rectangle.png"];
        }
    }
    if ([topic isEqualToString:@"gbenna/feeds/level"]){
        self.levelValueLabel.text = dataString;}
    if ([topic isEqualToString:@"xxxxxxx/feeds/date"]){
        self.dateValueLabel.text = dataString;}
    if ([topic isEqualToString:@"xxxxxx/feeds/battery"]){

        B = [dataString intValue];
        _batteryValueLabel.frame = CGRectMake(114, 287, B*1.7, 63);
        if (B <= 20) {
            _batteryValueLabel.image = [UIImage imageNamed:@"red rectangle.png"];
        }
        else if ((20< B)&& (B <= 100)) {
            _batteryValueLabel.image = [UIImage imageNamed:@"green rectangle.png"];
        }
        else if (B > 100) {
            _batteryValueLabel.image = [UIImage imageNamed:@"red rectangle.png"];
        }
    }
    if ([topic isEqualToString:@"xxxxxxx/feeds/trip"]){
        self.tripValueLabel.text = dataString;}
}
//THIS WORKS TO POST A VALUE TO SERVER
-(IBAction)Turnon:(id)sender;{
    if(trigger ==1){
        trip = @"0";
        trigger = 2;
    }
    else if(trigger==2){
        trip = @"100";
        trigger = 1;
    }
    NSData* data = [trip dataUsingEncoding:NSUTF8StringEncoding];
    [session publishData:data onTopic:@"xxxxx/feeds/trip" retain:NO qos:1 publishHandler:nil];
    NSLog(@"%@", trip);
    NSLog(@"%d",trigger);

}
@end

If someone could help I would really appreciate it.