I am trying to pass data BACK TO previous viewController.
Does anyone know how to pass data back from ViewController B to ViewController A? So I want a string to go 'from' BIDAddTypeOfDealViewController to BIDDCCreateViewController. A user edits viewController B and I want that edited data back in ViewController A where I then use it.
I am using the 'passing data back' section of this answer. How mine differs: Point 3 and 6 just mentions when views are popped so I have put that code in viewWillDisappear. I think that is correct? Also on Point 6 I did not initialise with nib as that is old. I'm using storyboards. And I did not add that last line as I do not believe I would have to push it. Pressing a button on my storyboard already takes me forward.
I think the problem may arise in BIDDCCreateViewController, I have the method but I cannot run it. To run a method it should go [self method]. I am unable to do that. Well that is just what I am guessing.
It compiles and runs fine just nothing is logged, so I don't know if it works.
UPDATE: I am unable to get the 'sendDataToA' method to execute.
#import <UIKit/UIKit.h>
#import "BIDAddTypeOfDealViewController.h"
@interface BIDDCCreateViewController : UIViewController
@property (strong, nonatomic) NSString *placeId;
- (IBAction)gotoBViewController:(id)sender;
@end
#import "BIDDCCreateViewController.h"
#import "BIDAddTypeOfDealViewController.h"
@implementation BIDDCCreateViewController
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
NSLog(@"SUCCESSFULLY PASSED PLACE ID: %@", self.placeId);
}
-(void)sendDataToA:(NSString *)myStringData
{
NSLog(@"Inside sendDataToA");
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Your string Data Showing" message:myStringData delegate:self cancelButtonTitle:@"Ok " otherButtonTitles:nil];
[alert show];
}
- (IBAction)gotoBViewController:(id)sender {
NSLog(@"pressed");
BIDAddTypeOfDealViewController *bidAddType = [[BIDAddTypeOfDealViewController alloc]init];
bidAddType.delegate = self;
}
@end
@protocol senddataProtocol <NSObject>
-(void)sendDataToA:(NSString *)myStringData;
@end
#import <UIKit/UIKit.h>
@interface BIDAddTypeOfDealViewController : UIViewController <UITextFieldDelegate>//Using this delegate for data a user inputs
@property(nonatomic,assign)id delegate;
//other textfield outlets not relevant
- (IBAction)chooseDiscountDeal:(id)sender;
@end
#import "BIDAddTypeOfDealViewController.h"
@interface BIDAddTypeOfDealViewController ()
@end
@implementation BIDAddTypeOfDealViewController
@synthesize delegate;
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
}
-(void)viewWillDisappear:(BOOL)animated
{
[delegate sendDataToA:@"Apple"];
}
@end
You can use a delegate. So in your ViewController B you need to create a protocol that sends data back to your ViewController A. Your ViewController A would become a delegate of ViewController B.
If you are new to objective C, please look at What is Delegate.
Create protocol in ViewControllerB.h :
#import <UIKit/UIKit.h>
@protocol senddataProtocol <NSObject>
-(void)sendDataToA:(NSArray *)array; //I am thinking my data is NSArray, you can use another object for store your information.
@end
@interface ViewControllerB : UIViewController
@property(nonatomic,assign)id delegate;
ViewControllerB.m
@synthesize delegate;
-(void)viewWillDisappear:(BOOL)animated
{
[delegate sendDataToA:yourdata];
}
in your ViewControllerA : when you go to ViewControllerB
ViewControllerA *acontollerobject=[[ViewControllerA alloc] initWithNibName:@"ViewControllerA" bundle:nil];
acontollerobject.delegate=self; // protocol listener
[self.navigationController pushViewController:acontollerobject animated:YES];
and define your function:
-(void)sendDataToA:(NSArray *)array
{
// data will come here inside of ViewControllerA
}
Edited :
You can See this example : How you can Pass data back to previous viewcontroller: Tutorial link