I have an NSMutableArray that I am trying to access from one of my ViewControllers to the other.
Here is what I am doing:
a.h:
#import "b.h"
.....
#property(nonatomic,strong) b *viewControllers;
a.m:
- (void)viewDidLoad
{
[super viewDidLoad];
UIStoryboard *storyboard = [UIStoryboard storyboardWithName:#"Main_iPhone" bundle:nil];
_viewControllers = [storyboard instantiateViewControllerWithIdentifier:#"createChallengeInfo"];
.....code....
}
....code....
-(IBAction)sendVideo:(id) sender
{
NSLog(#"%#",self.viewControllers.selectedCells);
}
Now when logging this I encounter an error, EXC_BAD_ACCESS (code=1,address =0x13765350).
Here is my other ViewController.
b.h:
...code....
#property (strong, nonatomic) NSMutableArray *selectedCells; <-- this is the array I want to access
...code...
b.m:
#import "a.h"
...import...
#interface b ()
#end
#implementation b
- (void)viewDidLoad
{
[super viewDidLoad];
/* INITIATE VARIABLE */
_selectedCells = [[NSMutableArray alloc] init];
....code....
}
...code...
So my issue is accessing, selectedCells. But firstly why am I getting a EXC_BAD_ACCESS? And secondly before I get the error It lays out the ViewController and shows the variable selectedCells as nil.
Suggestions, thoughts?
If "b" is embedded in a container view of "a", then it is already instantiated when "a" gets instantiated. Therefore, when you use instantiateViewControllerWithIdentifier:, you are creating a new instance, NOT the one you have on screen. Your viewDidLoad should look like this instead,
- (void)viewDidLoad
{
[super viewDidLoad];
_viewControllers = self.childViewControllers[0];
.....code....
}
Another way to get a reference to the embedded view controller is in prepareForSegue, which will be called right after your "a" controller is instantiated. Your "b" controller will be segue.destinationViewController.
Related
On a button press, I am trying to send data from Collection View Controller to my View Controller. Here is what I have so far:
CollectionViewController.h
#import <UIKit/UIKit.h>
#class CollectionViewController;
#protocol CollectionViewDelegate <NSObject>
-(void) sendTest;
#end
#interface CollectionViewController : UICollectionViewController
#property (nonatomic, weak) id<CollectionViewDelegate> deligate;
#end
CollectionViewController.m
-(void) viewDidLoad {
[super viewDidLoad];
}
...
NSLog(#"check");
[self.deligate sendTest];
NSLog(#"called");
FooViewController.m
#import "CollectionViewController.h"
#interface FooViewController () <CollectionViewDelegate> {}
#end
#implementation FooViewController
- (void)viewDidLoad {
[super viewDidLoad];
CollectionViewController *controler = [[CollectionViewController alloc] init];
controler.deligate = self;
}
- (void) sendTest {
NSLog(#"Delegates are great!");
}
Unfortunaly when I call [self.deligate sendTest]; nothing happens. I know it is called, because I get the check, called logs.
The main wrong thing is that you are creating a CollectionViewController yourself, but you shouldn't. The CollectionViewController that you want is instantiated automagically by the Storyboard. How to find this view controller?
1 - Catch it during the segue in FooViewController:
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
CollectionViewController *collectionViewController =(CollectionViewController *) segue.destinationViewController;
collectionViewController.deligate = self;
}
2 - Find it in within the child view controllers in FooViewController
self.childViewControllers
Does it help you?
Through delegation I created a view controller that takes the input from textfields and passes it back and adds it to an nsmutablearray, successfully adding a row for it. whenever i navigate away from the tableview my newly appended object just disappears. Here is some code to give you a better idea of what i might be doing wrong.
TableViewController.h -
#interface TableViewController : UITableViewController<UITableViewDelegate, UITableViewDataSource>
#property(strong,nonatomic)NSMutableArray *codeList;
#property(strong,nonatomic)NSMutableArray *codeArray;
#end
TableViewController.m -
#interface TableViewController ()
#end
#implementation MCTableViewController
#synthesize codeList;
#synthesize codeArray;
- (void)viewDidLoad {
[super viewDidLoad];
self.tableView.delegate = self;
self.tableView.dataSource = self;
self.codeList = [NSMutableArray arrayWithObjects:#"Array",
#"Pointer",
#"Class",
#"Protocol",
#"Delegate",
nil];
self.codeDescArray = [NSMutableArray arrayWithObjects:
#"Array Description",
#"Pointer Description",
#"Class Description",
#"Protocol Description",
#"Delegate Description",
nil];
)
In the same class I programmatically created a button that moves to the view where data is supposed to be passed back. code below. This is done through delegation.
- (void)addNewCodeButtonPressed {
AddNewCodeVC *addVC = [[AddNewCodeVC alloc] init];
addVC.dataDelegate = self;
UINavigationController *navBar = [[UINavigationController alloc]initWithRootViewController:addVC];
[self.navigationController presentViewController:navBar animated:YES completion:nil];
}
Here is where the delegate logic is created in AddNewCodeVC.h -
#import <UIKit/UIKit.h>
#import "TableViewController.h"
#class AddNewCodeVC;
#protocol addNewCellData <NSObject>
- (void)sendDataToTableView:(NSString*)code codeDesc: (NSString*)desc;
#end
#interface AddNewCodeVC : UIViewController<UITextFieldDelegate> {
__weak id dataDelegate;
}
#property(weak,nonatomic)id<addNewCellData>dataDelegate;
#property(strong,nonatomic)UITextField *codeTextfield;
#property(strong,nonatomic)UITextField *descTextfield;
#end
finally here is the AddNewCodeVC.m -
#import "AddNewCodeVC.h"
#interface AddNewCodeVC ()
#end
#implementation AddNewCodeVC
#synthesize dataDelegate;
- (void)viewDidLoad {
[super viewDidLoad];
self.codeTextfield.delegate = self;
self.descTextfield.delegate = self;
//Programmatically created both textfields, nothing special
}
//"saveNewCode" is action for another button i created
- (void)saveNewCode {
sendDataToTableView:self.codeTextfield.text codeDesc:self.descTextfield.text];
[self.dataDelegate sendDataToTableView:self.codeTextfield.text codeDesc:self.descTextfield.text];
NSLog(#"CODE: %#", self.codeTextfield.text);
NSLog(#"DESC: %#", self.descTextfield.text);
[self dismissViewControllerAnimated:YES completion:nil];
}
The code works but nsmutable array wont hold the passed values if i navigate away from the TableViewController. I think this is because my main view controller programmatically segues to the tableview controller and creates a new instance of it, so that might have some effect? I'll leave some code below just in case it is relevant.
MainviewController.m -
- (void) tableViewBtnPressed:(UIBarButtonItem *)sender {
TableViewController *tableVC = [[TableViewController alloc] init];
//This for another delegate I created, not relevant
tableVC.selectedDataDelegate = self;
UINavigationController *navBar = [[UINavigationController alloc]initWithRootViewController:tableVC];
[self.navigationController presentViewController:navBar animated:YES completion:nil];
}
Hopefully this code is enough to illustrate the problem, i hope someone has an idea whats going on with the NSMutableArray, and why it isn't holding any new objects that are passed into it, any help is appreciated.
I am trying to get a string from a view controller to another using delegate method.But the delegate method is not getting called.Below is the code
#protocol CustomDelegate<NSObject>
-(void)didDataRecieved;
#end
#interface CustomController:UIViewController
#property id<CustomDelegate>delegate;
#property(retain,nonatomic)NSString *string;
#end
#implementaion CustomController
-(void)viewDidLoad
{
string=#"hello";
if([self.delegate respondsToSelector#selector(didDataRecived)]) {
[self.delegate didDataRecieved];
}
}
-(IBACTION)gotoViewController
{
ViewController *view=[self.storyboard instantiateViewController:#"View"];
[self.navigationController pushViewController:view aniamted:YES];
}
#end
#interface ViewController:UIViewController<CustomDelegate>
#property (nonatomic,retain)CustomController *cust;
#end
#implementation ViewController
-(void)viewDidLoad
{
self.cust=[[CustomController alloc]init];
self.cust.delegate=self;
}
-(void)didDataRecieved
{
NSLog(#"data %#",self.cust.string);
}
#end
Can anyone point out where am going wrong...plz help.
edited the code..tried this way too.
if([self.delegate respondsToSelector#selector(didDataRecived)]){
[self.delegate didDataRecieved];
}
I will give you the sample coding.Customize the below code.
Here we have two view controllers.
ViewController
and
SecondViewController
in SecondViewController
.h
#import <UIKit/UIKit.h>
#class SecondViewController;
#protocol SecondViewControllerDelegate <NSObject>
- (void)secondViewController:(SecondViewController *)secondViewController didEnterText:(NSString *)text;
#end
#interface SecondViewController : UIViewController
#property (nonatomic, assign)id<SecondViewControllerDelegate> delegate;
#property (nonatomic, strong) IBOutlet UITextField *nameTextField;//It must connect as outlet connection
- (IBAction)doneButtonTapped:(id)sender;
#end
.m
#import "SecondViewController.h"
#interface SecondViewController ()
#end
#implementation SecondViewController
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
}
//Either use NSNotification or Delegate
- (IBAction)doneButtonTapped:(id)sender;
{
//Use Notification
[[NSNotificationCenter defaultCenter] postNotificationName:#"passingDataFromSecondViewToFirstView" object:self.nameTextField.text];
//OR Custom Delegate
[self.delegate secondViewController:self didEnterText:self.nameTextField.text];
[self.navigationController popViewControllerAnimated:YES];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
in ViewController
.h
#import <UIKit/UIKit.h>
#import "SecondViewController.h"
#interface ViewController : UIViewController<SecondViewControllerDelegate>
#property (nonatomic, strong) IBOutlet UILabel *labelName; //You must connect the label with outlet connection
- (IBAction)gotoNextView:(id)sender;
#end
.m
#import "ViewController.h"
#interface ViewController ()
#end
#implementation ViewController
- (void)viewDidLoad
{
[super viewDidLoad];
//addObserver here...
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(textFromPreviousViewControllerNotificationReceived:) name:#"passingDataFromSecondViewToFirstView" object:nil];
// Do any additional setup after loading the view, typically from a nib.
}
//addObserver Method here....
- (void)textFromPreviousViewControllerNotificationReceived:(NSNotification *)notification
{
// set text to label...
NSString *string = [notification object];
self.labelName.text = string;
}
- (IBAction)gotoNextView:(id)sender;
{
//If you use storyboard
SecondViewController *secondViewController = [self.storyboard instantiateViewControllerWithIdentifier:#"SecondViewController"];
//OR If you use XIB
SecondViewController *secondViewController = [[SecondViewController alloc] initWithNibName:#"SecondViewController" bundle:nil];
secondViewController.delegate = self;
[self.navigationController pushViewController:secondViewController animated:YES];
}
//Calling custom delegate method
- (void)secondViewController:(SecondViewController *)secondViewController didEnterText:(NSString *)text
{
self.labelName.text = text; //Getting the data and assign the data to label here.
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
For your understanding the code I create a simple passing data from one second view controller to first view controller.
First we navigate the view from first view controller to second view controller.
After that we send the data from second view controller to first view controller.
NOTE : You can either use NSNotification or Custom Delegate method for sending data from One View Controller to Other View Controller
If you use NSNotification, you need to set the postNotificationName for getting data in button action method.
Next you need to write addObserver in (sending data to your required View Controller) ViewController and call the addObserver method in same View Controller.
If you use custom delegate,
Usually we go with Custom Protocol Delegate and also we need to Assign the delegate here.
Very importantly we have to set the Custom Delegate Method in the Second View Controller.Because where we send the data to first view controller once we click the done button in second view controller.
Finally we must call the Custom Delegate Method in First View Controller, where we get the data and assign that data to label.Now you can see the passed data using custom delegate.
Likewise you can send the data to other view controller using Custom Delegate Methods
how you pushing your second controller? i cant see.
but your code working for me.
#implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
ViewController1 *vc = [ViewController1 new];
vc.delegate = self;
[self presentViewController:vc animated:YES completion:nil];
}
-(void)didDataRecieved
{
NSLog(#"recieved");
}
#end
I have been searching all morning how to do this. I have 2 View Controllers. From the root View Controller (ViewControllerA - which is a table view controller) you can go push to the second view controller (ViewControllerB).
In the ViewControllerB, there are two fields: contacts & textBody. When the user is done they can click on "Add". This will then go back to ViewControllerA. What I am trying to do now, is for every time that process occurs, all the information from ViewControllerB the user just added goes into a cell in ViewControllerA. The user can then add as many cells as they like.
What I can't do however, is get the information across the view controllers. I have been looking all morning at using the app delegate, singletons??, protocols, sharing properties, etc! But I am still stuck.
What I want to do, but can't, is for every time the user clicks "Add" on ViewControllerB, contacts & texts are put into an array. This array is then put into another array which holds all the smaller arrays which the user has created? If you have an ideas, or links to similar/sample code or tutorials, that would be much appreciated!
Try this using the delegate method as follows
Download Sample Project with XIBs
Download Sample Project With Storyboard
ParentViewController.h
#import <UIKit/UIKit.h>
#interface ParentViewController : UIViewController {
NSMutableArray *dataArray;
}
- (void)passData:(NSMutableArray *)array;
#end
ParentViewController.m
#import "ParentViewController.h"
#import "ChildViewController.h"
#implementation ParentViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Initialise the mutable array.
dataArray = [[NSMutableArray alloc] init];
}
- (IBAction)btnGoToSecondView:(id)sender {
ChildViewController *secondVC = [[ChildViewController alloc] initWithNibName:#"ChildViewController" bundle:nil];
secondVC.delegate = self;
[self presentViewController:secondVC animated:YES completion:nil];
}
- (void)passData:(NSMutableArray *)array {
[dataArray addObject:array];
NSLog(#"Data Passed = %#",dataArray);
}
#end
ChildViewController.h
#import <UIKit/UIKit.h>
#import "ParentViewController.h"
#class ParentViewController;
#interface ChildViewController : UIViewController {
NSMutableArray *tempArray;
}
#property (strong, nonatomic) IBOutlet UITextField *txtContact;
#property (strong, nonatomic) IBOutlet UITextField *txtTextBody;
#property(nonatomic, assign) ParentViewController *delegate;
#end
ChildViewController.m
#implementation ChildViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Initialise the mutable array.
tempArray = [[NSMutableArray alloc] init];
}
- (IBAction)btnPassDataBack:(id)sender {
if([self.delegate respondsToSelector:#selector(passData:)]) {
[tempArray addObject:_txtContact.text];
[tempArray addObject:_txtTextBody.text];
[self.delegate passData:tempArray];
}
[self dismissViewControllerAnimated:YES completion:nil];
}
- (void)viewDidUnload {
[self setTxtContact:nil];
[self setTxtTextBody:nil];
[super viewDidUnload];
}
#end
With Storyboard
If you are using storyboard then create a ParentViewController segue ChildViewController and give it a identifier in my sample it showChildView
Then use the following code to set the delegate
// Calling the segue to go to the child view and setting up the delegate.
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
if ([segue.identifier isEqualToString:#"showChildView"]) {
ChildViewController *childVC = segue.destinationViewController;
childVC.delegate = self;
}
}
Then to dismiss back to the ParentViewController use the following code (from my sample)
- (IBAction)btnPassDataBack:(id)sender {
if([self.delegate respondsToSelector:#selector(passData:)]) {
[tempArray addObject:_txtContact.text];
[tempArray addObject:_txtTextBody.text];
[self.delegate passData:tempArray];
}
[self.navigationController popToRootViewControllerAnimated:YES];
}
I would recommend using a singleton instance of your NSMutableDictionary as they have bailed me out of your exact situation multiple times (including custom frameworks and UITabBarControllers). Here is an example I'm currently using to implement a singleton. This methodology is also ARC-safe as well
mySingleton.h
#import <Foundation/Foundation.h>
#interface mySingleton : NSObject {
}
+ (NSMutableDictionary *) myMutableDict;
#end
mySingleton.m
#import "mySingleton.h"
#implementation mySingleton
+ (NSMutableDictionary *)myMutableDict
{
static NSMutableDictionary *singletonInstance = nil;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
singletonInstance = [[NSMutableDictionary alloc]init];
});
return singletonInstance;
}
#end
As long as you include mySingleton.h in all of your view controllers you can access the data via [mySingleton myMutableDict]. For example: [[mySingleton myMutableDict] setObject:myObject forKey:myKey];
Good luck!
If the information is really "global" - it has only one instance across the whole app - then you should create a singleton as DB80Buckeye suggested.
If the information is something that truly belongs to ViewController1 and you want it to be modified in ViewController2 (ie ViewController2 is really part of ViewController1, it just happens to be on another screen), then you should pass that as part of the constructor of ViewController2.
-(void)view_controller_1_that_push_view_controller_2_onto_the_stack {
ViewController2* vc2 = [[ViewController2 alloc] initWithInformation:your_information];
[self.navigationController pushViewController:vc2 animated:YES];
}
#interface ViewController2
-(id)initWithInformation:(YourInformationClass*)info;
#end
Another way is to use notifications.
There are two ways to go here. The standard pattern for doing this is delegation. You don't need a singleton. ViewControllerA manages and lists your data. ViewControllerB doesn't need to know anything about all of that data so there's no reason to expose it via a singleton, etc.
Create a delegate protocol in ViewControllerB's header file. Something like this:
#protocol ViewControllerBDelegate
- (void)addContact:(NSString *)contact withBody:(NSString *)textBody;
#end
Now, specify that ViewControllerA will implement the delegate protocol in its header:
#interface ViewControllerA : UIViewController <ViewControllerBDelegate>
Don't forget to import ViewControllerB.h at the top of ViewControllerA's header.
In ViewControllerA's implementation, implement the delegate method you specified in the protocol:
- (void)addContact:(NSString *)contact withBody:(NSString *)textBody {
[self.someArray addObject:[[SomeObject alloc] initWithContact:contact body:textBody]];
[self.tableView reloadData];
}
That's obviously just an example -- not sure how you're managing your data structure and it's probably better to insert the cell someplace that makes sense.
Declare a delegate reference in ViewControllerB's header:
#property (weak, nonatomic) id<ViewControllerBDelegate> delegate;
When you present ViewControllerB, set ViewControllerA as the delegate.
ViewControllerB *b = [[ViewControllerB alloc] init...];
b.delegate = self;
In the selector triggered by the add button in ViewControllerB, call back on the delegate before popping the view controller off the navigation stack:
[self.delegate addContact:contact withBody:text];
where contact and text are the values the user entered.
One could also use a block instead of a delegate but the principle is the same -- have the second view controller only be responsible for taking input, in your case, and pass it back to the view controller managing the data.
Alternatively for delegate suggest using the following:
ViewControllerA.h:
#property (nonatomic, strong) ViewControllerB* viewControllerB;
In ViewControllerA.m
if (!self.viewControllerB)
{
self.viewControllerB = [[ViewControllerB alloc] initWithNibName: #"ViewControllerBr" bundle: nil];
}
[self.navigationController pushViewController: self.viewControllerB
animated: YES];
...
- (void) viewWillAppear: (BOOL) animated
if (self.viewControllerB)
{
NSString* contact = self.viewControllerB.contact;
NSLog(#"%#", contact);
}
...
Alright, so this is an extension to a question I asked last night. I have a little firmer grasp on how data can be passed between view controllers using various techniques. I wanted to go the MVC route, and creating a Singleton class seems the closest concept similar to MVC.
Basically I created a simple app with two View Controllers and a singleton class. I am trying to pass the value of a text field into a UILabel. For whatever reason it isn't working. This is what my code looks like.
ViewController.h
#import <UIKit/UIKit.h>
#import "Model.h"
#import "ViewController2.h"
#interface ViewController : UIViewController {
NSString *text2pass;
}
#property (weak, nonatomic) IBOutlet UITextField *tf;
#property (weak, nonatomic) IBOutlet UILabel *btn;
- (IBAction)go:(id)sender;
#end
ViewController.m
#import "ViewController.h"
#interface ViewController ()
#end
#implementation ViewController
#synthesize tf = _tf;
#synthesize btn = _btn;
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
NSString *tfstring = _tf.text;
NSLog(#"string = %#",tfstring);
}
- (void)viewDidUnload
{
[self setTf:nil];
[self setBtn:nil];
[super viewDidUnload];
// Release any retained subviews of the main view.
}
- (IBAction)go:(id)sender {
NSLog(#"btn pressed");
UIStoryboard *storyboard = [UIStoryboard storyboardWithName:#"MainStoryboard" bundle:nil];
ViewController2 *vc2 = (ViewController2 *) [storyboard instantiateViewControllerWithIdentifier:#"home"];
text2pass = _tf.text;
[self passValues];
[self presentModalViewController:vc2 animated:YES];
}
-(void) passValues {
Model *model = [Model sharedModel];
model.passedText = text2pass;
}
#end
ViewController2.h
#import <UIKit/UIKit.h>
#import "ViewController.h"
#interface ViewController2 : UIViewController {
NSString *passedText;
}
#property (nonatomic)NSString *passedValue;
#property (weak, nonatomic) IBOutlet UILabel *lbl;
- (IBAction)back:(id)sender;
#end
ViewController2.m
#import "ViewController2.h"
#interface ViewController2 () {
NSString *passedtext;
}
#end
#implementation ViewController2
#synthesize lbl = _lbl;
#synthesize passedValue = _passedValue;
- (void)viewDidLoad
{
// do code stuff here
NSLog(#"passedText = %#",passedText);
_lbl.text = passedText;
[super viewDidLoad];
}
- (void)viewDidUnload
{
[self setLbl:nil];
[super viewDidUnload];
// Release any retained subviews of the main view.
}
- (IBAction)back:(id)sender {
UIStoryboard *storyboard = [UIStoryboard storyboardWithName:#"MainStoryboard" bundle:nil];
ViewController *vc = (ViewController *) [storyboard instantiateViewControllerWithIdentifier:#"welcome"];
[self presentModalViewController:vc animated:YES];
}
#end
Model.h
#import <Foundation/Foundation.h>
#interface Model : NSObject {
NSString *passedText;
}
#property (nonatomic, strong) NSString* passedText;
+ (Model *) sharedModel;
#end
Model.m
#import "Model.h"
#implementation Model
#synthesize passedText = _passedText;
static Model *sharedModel = nil;
+ (Model *) sharedModel {
#synchronized(self){
if (sharedModel == nil){
sharedModel = [[self alloc] init];
}
}
return sharedModel;
}
#end
The project can be downloaded in its entirety from here http://chrisrjones.com/files/KegCop-Test.zip
If you know why the UILabel is not displaying the text field text let me know. Oh I pretty much followed this -> http://www.youtube.com/watch?v=ZFGgMPcwYjg&feature=plcp
Your addressing, and memory management is just plain... off. Firstly, there's absolutely no reason to create a singleton for this, but that's beside the point here.
Secondly, when declaring properties, (atomic, assign) is defaulted to if not otherwise specified, which means your string:
#property (nonatomic)NSString *passedValue;
is weak sauce, ripe for deallocation and destruction at a moments notice. Declare it copy, strong, or retain.
Thirdly, there's absolutely no reference to your singleton in the pushed view controller, yet you seem to have the belief that objects that are named the same in different classes retain their value (especially when #import'ed). Not so. You need to reference your singleton and pull the value of [Model sharedModel].passedText into that text field.
In fact, I fixed your sample in two lines:
//ViewController2.m
#import "ViewController2.h"
//actually import the singleton for access later
#import "Model.h"
#interface ViewController2 () {
NSString *passedtext;
}
#end
#implementation ViewController2
#synthesize lbl = _lbl;
#synthesize passedValue = _passedValue;
- (void)viewDidLoad
{
// do code stuff here
NSLog(#"passedText = %#",passedText);
//actually reference the singleton this time
_lbl.text = [Model sharedModel].passedText;
[super viewDidLoad];
}
- (void)viewDidUnload
{
[self setLbl:nil];
[super viewDidUnload];
// Release any retained subviews of the main view.
}
- (IBAction)back:(id)sender {
UIStoryboard *storyboard = [UIStoryboard storyboardWithName:#"MainStoryboard" bundle:nil];
ViewController *vc = (ViewController *) [storyboard instantiateViewControllerWithIdentifier:#"welcome"];
[self presentModalViewController:vc animated:YES];
}
#end
Which yields this:
I wouldn't recommend using a Singleton as a good way to pass data around your application. Most apps are simple enough that this kind of central access is not necessary, and it usually creates a maintenance nightmare... but I don't think the fact that you're using a Singleton is actually important to getting your code working.
Assuming you have access to the data in ViewController1, in your case through the a Singleton instance of Model (which needs a more descriptive name), then all you have to do is pass through the data to ViewController2 when it is created and presented, which eliminates the need for a Singleton at all.
Once you create the controller, set the data you need, and then present the view controller - which is basically what you're doing anyway.
As to why it's not working: Is the view controller being presented, just not with the correct data? Or is there actually an issue presenting the controller at all? I would set a breakpoint in the go: action of ViewController1, make sure the data you expect is in the textfield, correctly populates the Model and that the value is correctly pulled out of the Model in ViewController2.
Unless you've removed some of the code, it looks like you correctly populate the Model property in ViewController1, but in ViewController2 you refer to a local ivar passedTextrather than pulling it from the model.
On a separate note, the way to go back from a presented modal view controller is usually to dismiss that controller, not to re-create the initial controller and present that over the top.