Passing NSMutableArray from Modal View Controller to Parent View

Question

I'm struggling to pass a NSMutable array from a Modal View controller back to the view controller I came from.

This is my current method:

FirstViewController.h
#import "SecondViewController.h"

@property (strong, nonatomic) IBOutlet NSMutableArray *passedRecipientsArray;


FirstViewController.m
@synthesize passedRecipientsArray = _passedRecipientsArray;

- (void)viewDidAppear:(BOOL)animated {
    NSLog(@"passedRecipientsArray: %@", self.passedRecipientsArray);
}

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    if([[segue identifier] isEqualToString:@"addContact"]){
        UINavigationController *nav = [segue destinationViewController];
        SecondViewController *secondViewController = (SecondViewController *)nav.topViewController;
        secondViewController.emailContact = @"TRUE";
    }
}

SecondViewController.h
@property (strong, nonatomic) IBOutlet NSMutableArray *selectedContactsArray;


SecondViewController.m
@synthesize passedRecipientsArray = _passedRecipientsArray;

- (void)closeWindow
{
    if([self.selectedContactsArray count] != 0){
        NSLog(@"PASS ME: %@", self.selectedContactsArray);

        FirstViewController *firstViewController = [[FirstViewController alloc] init];

        if(firstViewController.passedRecipientsArray == nil) firstViewController.passedRecipientsArray = [[NSMutableArray alloc] init];
        firstViewController.passedRecipientsArray = self.selectedContactsArray;

        [self dismissModalViewControllerAnimated:YES];
    }
}

Is there a better way of doing this? I've tried to used this: How to pass object on modal view's dismissal but get very confused.

Does anyone have a good tutorial/clear easy way of doing what I'm after? Can anyone tell me where I'm going wrong?

Shamsudheen TK · Answer 1 · 2012-10-16T09:26:43.570

Don't allocate FirstViewController inside the SecondViewController. Because FirstViewController is your parent class.Old FirstViewController objects will be null after the re-allocation

Pass the FirstViewController instance instead of writing

FirstViewController *firstViewController = [[FirstViewController alloc] init];

Example:

SecondViewController.h

#import "FirstViewController.h"

FirstViewController *firstViewController;

@property (strong, nonatomic) IBOutlet NSMutableArray *selectedContactsArray;
@property (strong, nonatomic)  FirstViewController *firstViewController;

SecondViewController.m
@synthesize passedRecipientsArray = _passedRecipientsArray;
@synthesize firstViewController;

- (void)closeWindow
{
    if([self.selectedContactsArray count] != 0){          

                if(self.firstViewController.passedRecipientsArray == nil)
                       self.firstViewController.passedRecipientsArray = self.selectedContactsArray;         

        [self dismissModalViewControllerAnimated:YES];
    }
}

Then modify your FirstViewController as

SecondViewController *secondViewController;

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    if([[segue identifier] isEqualToString:@"addContact"]){
        UINavigationController *nav = [segue destinationViewController];
        secondViewController = (SecondViewController *)nav.topViewController;
        secondViewController.emailContact = @"TRUE";
       secondViewController.firstViewController = self;
    }
}

I'm now getting an error on `@property (strong, nonatomic) FirstViewController *firstViewController;` saying 'Unknown Type name FirstViewController' and 'Property with retain (or strong) attribute must be type' — davidford.me, Oct 16 '12 at 10:24

score 1 · Answer 2 · answered Oct 16 '12 at 09:27

Firstly do not create and allocate another instance of firstViewController in secondViewController..instead..create a property FirstViewController *firstViewController in secondViewController further synthesize it in secondViewController .m file...

follow the rectified code

FirstViewController.h
#import "SecondViewController.h"

@property (strong, nonatomic) IBOutlet NSMutableArray *passedRecipientsArray;


FirstViewController.m
@synthesize passedRecipientsArray = _passedRecipientsArray;

- (void)viewDidAppear:(BOOL)animated {
    NSLog(@"passedRecipientsArray: %@", self.passedRecipientsArray);
}

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    if([[segue identifier] isEqualToString:@"addContact"]){
        UINavigationController *nav = [segue destinationViewController];
        SecondViewController *secondViewController = (SecondViewController *)nav.topViewController;
        secondViewController.firstViewController = self;  // u should create firstViewController first in secondViewController class making it a property

        secondViewController.emailContact = @"TRUE";
    }
}

then in secondViewController

     SecondViewController.h
@interface FirstViewController : UIViewController{
FirstViewController *firstViewController;
}
        @property (strong, nonatomic) IBOutlet NSMutableArray *selectedContactsArray;
        @property(nonatomic,strong) FirstViewController *firstViewController;

    SecondViewController.m

     @synthesize passedRecipientsArray = _passedRecipientsArray;
        @synthesize firstViewController
     - (void)closeWindow
            {
                if([self.selectedContactsArray count] != 0){
                    NSLog(@"PASS ME: %@", self.selectedContactsArray);



                if(firstViewController.passedRecipientsArray == nil)  {

                firstViewController.passedRecipientsArray = [[NSMutableArray alloc] init];
                firstViewController.passedRecipientsArray = self.selectedContactsArray;

                [self dismissModalViewControllerAnimated:YES];
            }
        }
    }

score 0 · Answer 3 · answered Oct 16 '12 at 10:02

0

I am just wondering why don't you add protocol to your model view? You can set NSMutableArray in model view and then get it from parent view.

answered Oct 16 '12 at 10:02

brianLikeApple

4,262
1
27
46

@DavidFord I give you link tutorial, just follow it. What I learn protocol is from here as well. [How to pass parameters from one view to another view](http://www.theappcodeblog.com/2011/04/15/passing-data-between-views-tutorial-using-a-protocol-delegate-in-your-iphone-app/) – brianLikeApple Oct 16 '12 at 10:50

Passing NSMutableArray from Modal View Controller to Parent View

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