CODEWITHSUNDEEP
iosobjective-c
Adam G
Adam G

Reputation: 1188

Objective C - Pass Text Field Value to NSString in another class

In my app users are required to verify their phone number to register. In the first view, they enter their phone number and receive an SMS. In the second view, they enter the SMS code, and in the third view, they complete their profile.

I am trying to pass the value of the user's phone number from View 1 to View 3.

Please see below:

View1.m

    ProfileCreateViewController *pc = [[ProfileCreateViewController alloc] init];

    pc.userPhoneNumber = [NSString stringWithFormat:@"%@", self.userPhoneNumber.text];

    // Perform segue to View 2

    - (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {

    EnterCodeViewController* vc = [segue destinationViewController];
    vc.verification = _verification;

}

View 3.h

@interface ProfileCreateViewController : UIViewController

.....

@property (nonatomic, strong) NSString *userPhoneNumber;

@end

View3.m

@synthesize userPhoneNumber;

- (void)viewDidLoad {

    [super viewDidLoad];
    NSLog(@"My phone number is: +1%@", userPhoneNumber);

}

However, when I get to View3, in the log I am getting 'My phone number is +1(null)'

Why isn't the value passing to View3?

Upvotes: 0

Views: 1500

Answers (4)

Rufus Mall
Rufus Mall

Reputation: 589

"for my own future reference, I'd still like to know why my code isn't working"

Hi there, It is difficult for me to know without a complete code sample. However, from what you have posted I think my guess here is correct.

In View1 when you manually alloc/init the "ProfileCreateViewController" you are creating an instance of the viewController and setting a property on it. However, if you are then using a storyboard segue from viewController2 (EnterCodeViewController) to show viewController3 (ProfileCreateViewController) the storyboard segue will instantiate a ProfileCreateViewController for you, and the one you have created will just be ignored.

I believe what want to do is build some sort of service (I guess you could store it in NSUserDefaults as the other guy suggested). The other thing you can do is create a "UserProfile" object inside the ProfileCreateViewController. This will have a property "phoneNo" and "verificationCode". As you get the data, you populate the object and then pass the object to "EnterCodeViewController" which will then check the verification against the expected code, then if it succeeds pass the full object to the final viewController (ProfileCreateViewController) inside "PrepareForSegue".

If you are using storyboard segue's to manage all of your Segue's you should almost never have to manually alloc/init a viewController.

You can confirm this by pausing in the debugger and taking a note of the memory address of the one you alloc/init and then pause again and take the memory address of "self" once you are inside the "ProfileCreateViewController" with the null property. The memory address's will be different.

If you are still having trouble if you post more of the source code I can help you out. You seem to be new to iOS development. I recommend you check out "http://www.raywenderlich.com". This is a site that has been used by lots of people to learn the basics of iOS and is pretty good! Hope this helps.

Upvotes: 0

Rohit Kumar
Rohit Kumar

Reputation: 887

Use copy instead of strong

@property (nonatomic, copy) NSString *userPhoneNumber;

Check if you have set nil to the textField's text elsewhere. Use NSLog before assigning the text to verify that the text is being assigned or hard code a string to verify you are really getting nil in VC3.

Upvotes: 0

Fran Martin
Fran Martin

Reputation: 2369

If you are using segues you just need to implement the method prepareForSegue like this:

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    if ([[segue.destinationViewController class]
      isSubclassOfClass:[ProfileCreateViewController class]]) {
        ProfileCreateViewController *profileCreateVC =
    (ProfileCreateViewController *)segue.destinationViewController;
        profileCreateVC.userPhoneNumber = [NSString stringWithFormat:@"%@", self.userPhoneNumber.text];
    }
}

Upvotes: 2

George Papagiannis
George Papagiannis

Reputation: 13

I would suggest with my little Objective C experience that you could save the object to NSUserDefaults or you could just save the string and then retrieve at the 3rd view.

To save only the string:

NSUserDefaults *saveNumber = [NSUserDefaults standardUserDefaults];
    [saveNumber setObject:self.userPhoneNumber.text forKey:@"usersPhoneNumber"];
    [saveNumber synchronize];

Then load it back to the View3.m

NSString *phoneNum = [[NSUserDefaults standardDefaults]objectForKey:@"usersPhoneNumber"];
NSLog(@"My phone number is:+1%@",phoneNum);

I am not sure if this is what you are looking for, but I hope it helps

(In order to save the whole object you will have to use -encodeWithCoder & -initWithCoder at the View3.m file and the perform [NSKeyedArchiver archiveWithRootObject:yourObject] to NSData and then save the NSData to the NSUserDefaults).

Upvotes: 1

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