How to copy text from one ViewController to another?

Question

I'm writing a little quiz application. So I have a first view, where I ask a person to enter his/her name and a button which is the IBAction to go the next view with the first question. In the end, after a person has answered all questions, comes the congratulations view, where I want to copy the name, that was entered on the first view. Say there will be a phrase "Well done, John!" How can I do it?

On the first view(FirstViewController) I made a textfield

IBOutlet UITextField *text1;

And on the last view in .h:

IBOutlet UITextField *text2; 

and

-(IBAction)copy:(id)sender;

And in .m:

- (IBAction)copy:(id)sender
{
    [text2 setText:[text1 text]];
}

and

#import "FirstViewController.h"

But it says identifier text1 is undefined

I don't know what else to do...

Answer 1

Override the init method of SecondViewController as follows

-(id)initWithUsername:(NSString *)username
 {
      //create instance and then do 
      text2.text = username ;
 }

And in the FirstViewController , where you create the instance of SecondViewController init it using the above

  SecondViewController *second = [[SecondViewController alloc] initWithUsername:text1.text]; 

Answer 2

For passing value from one VC to other you have to do following code :

1. First declare local variable in next view where you want to move like.

   @property(nonatomic, strong) NSString *personName;
   

2. Now prepare object of second VC in the first VC.m file on button click action. But before that must set storyboard identifier of that second VC in storyboard.

   SecondViewController *obj = (SecondViewController *) [self.storyboard instantiateViewControllerWithIdentifier:@"SecondViewController"];
   obj.personName = self.txtUserName.text;
   

3. Now go on there on second VC and do whatever you want.

   Note : Here you don't need to used userdefaults, OR prepared init methods with parameters, OR using delegates etc.

Answer 3

You can override the

        - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil

method of last view controller with something like:

        - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil andUserName:(NSString*)userName

(don't forget to declare this method in your .h file.)

Now while initializing your last view controller, you can pass the name of the user to last view controller.

In the implementation of the this overriden method in last view controller, copy this name in some local variable. and use it.

Hope this will solve your problem.

Answer 4

In your firstView add NSString with its property
Something like this in .h file

NSString *username;

and

@property (nonatomic , retain) NSString *username;

in .m file

username = text1.text;

In LastView
im .m file

#import "FirstView.h"

And where ever you want username try this

FirstView *firstview = [[FirstView alloc] init];
text2 = firstview.username;

Hope it works..!!

Answer 5

The best way to do this would be taking the variables you need on various views and handling them on the delegate since the delegate has access to everything. Making a Global variable is never advisable that is what the delegate is for.

You can refer to this question that treats the same issue: Passing data between view controllers

Answer 6

You can add a NSString member (along with a property) in the application delegate class.

/// AppDelegate.h, or whatever it's called in your application
@interface AppDelegate : NSObject <UIApplicationDelegate> {
    NSString *username;
    // <rest of the members>
}
...
@property (nonatomic, retain) NSString *username;
@end

/// AppDelegate.m
@implementation AppDelegate
@synthesize username;
@end

/// FirstViewController.m
-(void)viewDidDissappear:(BOOL)animated{
    [super viewDidDissappear:animated];
    AppDelegate *appDelegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];
    appDelegate.username = text1.text;
}

/// LastViewController.m (or whatever it's called)
-(void)viewDidLoad{
    [super viewDidLoad];
    AppDelegate *appDelegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];
    [text2 setText:[NSString stringWithFormat:@"Well done %@", appDelegate.username]];
}

Ok, so for everyone to be happy, you can (and are suggested to) create your own singleton class in which you can hold non-persistent global variables, and use in the code above instead of the application delegate.

/// SharedData.h
@interface SharedData: NSObject {
    NSString *username;           /// or instead you can have a NSMutableDictionary to hold all shared variables at different keys
}
+(SharedData *)sharedInstance;

@property(nonatomic, retain) NSString *username;
@end

/// SharedData.m
#include "SharedData.h"

static SharedData *_sharedInstance=nil;
@implementation SharedData
@synthesize username;
+(SharedData)sharedInstance{
    if(!_sharedInstance){
        _sharedInstance = [[SharedData alloc] init];
    }
    return _sharedInstance;
}
@end

Answer 7

I would make use of NSUserDefaults to set the user's name when they enter it. Then, in your last view controller, just query NSUserDefaults again for the name you want. Granted, this is still global state, but NSUserDefaults is meant for this sort of purpose:

// In the first view controller

NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
[userDefaults setObject:@"John Doe" forKey:@"XXUserNameKey"];       // This should actually be an extern for your app to use globally

// In the last view controller

NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
NSString *userName = [userDefaults stringForKey:@"XXUserNameKey"];

Adding state to your app delegate is an abuse of the design pattern.

Also, I should clarify that NSUserDefaults should not be used as a general-purpose storage container. Its intent is for common, shared data like user names, preferences, etc. Something like the name a user enters at the beginning of a game seems to fall within the usage pattern.