How to pass data to parent view IOS

Question

I know this question is asked once every two days. I can not see what I am doing wrong though. I have a storyboard navigation controller based app.

My notification and pop / push segues works well, only thing is I can not add string to parents view NSmutablearray.

I want to add a string object to parent view's nsmutablearray. My decent code does not pass any data.

parent.h

@interface CreaatePlistTableViewController : UITableViewController<UITableViewDelegate, UITableViewDataSource>{

    NSMutableArray *presenterList;

}
@property (nonatomic, strong) NSMutableArray *presenterList;

parent.m

NSString * const NOTIF_CreatePlist_UpdateTableview= @"CreatePlist/UpdateTableview";
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 * Private interface definitions for update tableview
 *~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
@interface CreaatePlistTableViewController (private)
- (void)CreatePlistUpdateTableview:(NSNotification *)notif;
@end

@implementation CreaatePlistTableViewController
@synthesize presenterList=_presenterList;

- (void)viewDidLoad
{
    [super viewDidLoad];

    _presenterList=[[NSMutableArray alloc] init];

    // Register observer to be called when logging out
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(CreatePlistUpdateTableview:)
                                                 name:NOTIF_CreatePlist_UpdateTableview object:nil];

    NSLog(@"Presenter List: %@", _presenterList);

}


- (void)CreatePlistUpdateTableview:(NSNotification *)notif{
    NSLog(@"Notification recieved");
    NSLog(@"Presenter List: %@", _presenterList);
    [_createPlistTableview reloadData];
}

child.h

@interface AddPresenterViewController : UITableViewController<UITextFieldDelegate,UIAlertViewDelegate>{
    CreaatePlistTableViewController *crereaatePlistTableViewController;
}
@property(nonatomic,strong) CreaatePlistTableViewController *crereaatePlistTableViewController;

child.m

@synthesize crereaatePlistTableViewController=_crereaatePlistTableViewController;
//finished adding presenter
-(IBAction)finishedAddingPresenter:(id)sender{

    //some xml string here
    NSLog(@"final result XML:\n%@", writer.XMLString);


    _crereaatePlistTableViewController=[[CreaatePlistTableViewController alloc]init];
    //add object to parents view data source
    [_crereaatePlistTableViewController.presenterList addObject:writer.XMLString];

    //dismiss the view
     [self.navigationController popViewControllerAnimated:YES];

    //notify the parent view to update its tableview

    [[NSNotificationCenter defaultCenter] postNotificationName:@"CreatePlist/UpdateTableview" object:nil];

}

Output

Notification recieved
Presenter List: (
)

So notification works when I click the button. But it does not pass object to nsmutablearray.

What I am doing wrong here ? How can I add an object to parent view's nsmutablearray?

How do you pass the parent controller to the child controller ? (i.e. does the child's crereaatePlistTableViewController points to the same parent instance ? ) — giorashc, Nov 06 '12 at 14:53
I dont pass any data to child view but I push child view with push segue. Besides my switching and notification methods seems working only problem is it does not add string to parents nsmutablearray — Mord Fustang, Nov 06 '12 at 14:55
Stop using notification and start using blocks : http://developer.apple.com/library/ios/#documentation/cocoa/conceptual/Blocks/Articles/bxUsing.html — TheRonin, Nov 06 '12 at 15:13

score 0 · Answer 1 · edited May 23 '17 at 12:22

0

You wrote this.

[_crereaatePlistTableViewController.presenterList addObject:writer.XMLString];

Do you ever initialize the array? No. Use the debugger and you will see that at this line the presenterList is nil.

Now as a point of style. Avoid using NSNotificationCenter to pass data or signaling other objects. @TheRonin gave a handy link. You should also look into some tutorials on Segues, because these are solved problems.

This is another related post that you might find interesting.

edited May 23 '17 at 12:22

Community

1
1

answered Nov 06 '12 at 15:45

Cameron Lowell Palmer

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actually I did init my array in parents view viewdidload. I have added viewdidload function to question – Mord Fustang Nov 06 '12 at 15:53
and writer and XMLString? Are they nil? – Cameron Lowell Palmer Nov 06 '12 at 19:35
No I can see a regular xml string with NSlog, according to answer there might be something wrong with my allocation of parent class object – Mord Fustang Nov 07 '12 at 14:30
You're using ARC? Then that is your issue. – Cameron Lowell Palmer Nov 08 '12 at 09:12
Your issue is ARC deallocating the instance of the table view when the child class completes. Create the table view in the parent. – Cameron Lowell Palmer Nov 08 '12 at 09:33

score 0 · Accepted Answer · answered Nov 06 '12 at 18:14

0

It seems everything is good except your alloc of parent view object I am not that familiar with storyboard but You said you are using navigation navigation controller

so change this

 _crereaatePlistTableViewController=[[CreaatePlistTableViewController alloc]init];

to

 _crereaatePlistTableViewController= [self.navigationController.viewControllers objectAtIndex:0];

It may work I am not sure

answered Nov 06 '12 at 18:14

SpaceDust__

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why my method of allocation does not work ? Is not this a regular way? – Mord Fustang Nov 06 '12 at 18:18

How to pass data to parent view IOS

2 Answers2