how to send data back with dismissViewController - ios

Question

i have 2 views in iPhone application. FirstViewController and MultiSelectViewController.
in FirstViewController there is a button to go to MultiSelectViewController. In MultiSelectViewController i have a tableviewcontroller to multiselect and send result back to FirstViewController with Done button
my problem is with done button. i don't know how to send data back to the FirstViewController. it has to be with dissmissviewcontroller.
this is .h file of MultiSelectViewController
#protocol MultiSelectDelegate <NSObject>
-(void) multiselectViewControllerDismissed;
#end
#interface MultiSelectViewController : UITableViewController
{
__weak id myDelegate;
}
#property(nonatomic,retain)NSArray *myData;
#property(nonatomic, retain)NSMutableArray *selectedData;
#property (nonatomic, weak) id<MultiSelectDelegate> myDelegate;
this is my done button in .m file of MultiSelectViewController
- (void)viewDidLoad
{
[super viewDidLoad];
self.tableView.allowsMultipleSelection = YES;
selectedData=[[NSMutableArray alloc] init];
UIBarButtonItem *barButton = [[UIBarButtonItem alloc] initWithTitle:#"Done"
style:UIBarButtonItemStyleBordered
target:self
action:#selector(multiselectViewControllerDismissed)];
self.navigationItem.rightBarButtonItem = barButton;
}
and lastly here is my done button action:
-(void)multiselectViewControllerDismissed
{
NSLog(#"%#",selectedData);
}
i don't understand how can i send data and get back in FirstViewController

Answer 1

You redefine
multiselectViewControllerDismissed delegate method as
multiselectViewControllerDismissedWithData:(NSMutableArray *)dataSelected
And, in .h file of FirstViewController implement the delegate i.e.,
#interface FirstViewController: UIViewController <MultiSelectDelegate>
and in the button action of FirstViewController.m assign delegate of MultipleSelectViewController as self. ie.,
MultipleSelectViewController * msvc = [[MultipleSelectViewController alloc] init];
msvc.myDelegate = self;
and implement
-(void)multiselectViewControllerDismissedWithData:(NSMutableArray *)dataSelected
this method in FirstViewController.m
And, in the Done button action method of MultipleSelectViewController.m, call method multiselectViewControllerDismissedWithData with delegate i.e.,
[self.myDelegate multiselectViewControllerDismissedWithData:selectedData];
That's it.
You could now pass selectedData array from MultipleSelectViewController to FirstViewController

Answer 2

Two standard ways of passing data in obj-c:
Use references and assign manually. In your example, the first view controller passes a reference of itself to the second view controller. The second view controller assigns a designated property with the required data using the reference.
The publisher-subscriber pattern using LocalNotifications. The first view controller listens for a particular location notification, and the second view controller, before being dismissed, does a broadcast with the data.
I'd recommend the 1st approach for your example. Some sample code:
In the .h file:
#interface FirstViewController:UIViewController
#property NSMutableArray *receivedData; //property to receive selected data
#end
In the .m file:
MultiSelectViewController *msvc = [MultiSelectViewController alloc] init];
msvc.presentingViewController = self; // pass reference of 1st VC to 2nd VC
[self presentViewController:msvc animated:YES];
In MultiSelectViewController.h file:
#import "FirstViewController.h"
#interface MultiSelectViewController: UITableViewController
...
#property FirstViewController *presentingViewController;
...
#end
In MultiSelectViewController.m file:
-(void)multiselectViewControllerDismissed
{
NSLog(#"%#",selectedData);
presentingViewController.receivedData = selectedData;
}

Answer 3

first create your delegate method as
-(void)dismiss:(NSString *)str;
while did select get a value from based on indexpath.row
and store it as nsstring.
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
self.valueString=[NSString stringWithFormat:#"%#",[self.arrayValue objectAtIndex:indexPath.row]];
NSLog(#"%d",indexPath.row);
}
done button click:
call your delegate method like
[self. myDelegate dismiss:"your string which you get from table"]
[[self navigationController] popViewControllerAnimated:YES];
and in your first view controller…
import the view controller class and call delegate method..
create instance for second view controller...
MultiSelectViewController *txtNext=[[MultiSelectViewController alloc]init];
txtNext. myDelegate =self;
then
-(void)dismiss:(NSString *)str
{
NSString *strng=str;
nslog("%#",strng);
}