Passing variables through views

[cliaco]

Hi,
I am trying to display 3 views successively with a button in each view, but I loose my value when I call the third one.

In views 2 and 3 I have declared a NSString (key) in the interface, and I set its value in the preceding view just before pushing the view :

- (IBAction)ButtonPressed : (id)sender{

viewController *myView = [[viewController alloc]initWithNibName:nil bundle:nil];

myView .key= key;

myView .modalTransitionStyle =
UIModalTransitionStyleFlipHorizontal;
[self presentModalViewController:myView animated:YES];
[myView release];
}

In my 2 view, when loading i have the correct value in key, but when I press the button, the value is "out of scope".

How can i keep my value, so i could pass it to the third view ?

Is ther a better way to do that ?

I thank you for your help

Christophe

[RLScott]

Originally Posted by cliaco

In my 2 view, when loading i have the correct value in key, but when I press the button, the value is "out of scope".

What do you actually see that tells you it is "out of scope"?

[cliaco]

Originally Posted by RLScott

What do you actually see that tells you it is "out of scope"?

in my second view, in ButtonPress, I set a breakpoint, and "key" is out of scope.
So it is not "passed" to the third view.

[RLScott]

Originally Posted by cliaco

in my second view, in ButtonPress, I set a breakpoint, and "key" is out of scope.
So it is not "passed" to the third view.

Then post the code that shows how "key" is defined and how you are passing it from one view controller to another. Without all the relevant code posted, it is impossible to say what might be wrong.

[cliaco]

Hi,
This is the code.

I have only kept what seems to me to be important. Tell me if you prefer the full code.

key = cleMission

Thanks for your help

Christophe

// detailMissionController.h
#import <UIKit/UIKit.h>

@interface detailMissionController : UIViewController {
NSString *cleMission;
}

@property (nonatomic, copy) NSString *cleMission;


// This is the view3 button
- (IBAction)pointsControleButtonPressed : (id)sender;

@end


// detailMissionController.m

#import "detailMissionController.h"
#import "pointsControleController.h"


@implementation detailMissionController


@synthesize cleMission;


- (IBAction)pointsControleButtonPressed : (id)sender{

pointsControleController *pointControle = [[pointsControleController alloc]initWithNibName:nil bundle:nil];

pointControle.cleMission = cleMission;

pointControle.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
[self presentModalViewController : pointControle animated:YES];
[pointControle release];
}



@end

[RLScott]

I assume that cleMission is what is "out of scope" in

pointControle.cleMission = cleMission;

?

If so, then where is cleMission set? You can't set pointControle.cleMission from cleMission if cleMission is not set first...

[cliaco]

Originally Posted by RLScott

I assume that cleMission is what is "out of scope" in

pointControle.cleMission = cleMission;

?

If so, then where is cleMission set? You can't set pointControle.cleMission from cleMission if cleMission is not set first...

Yes, sorry, in the first view I set cleMission like that :

pointControle.cleMission = @"456";

[RLScott]

Originally Posted by cliaco

Yes, sorry, in the first view I set cleMission like that :

pointControle.cleMission = @"456";

That is not the same cleMission.

[cliaco]

Originally Posted by RLScott

That is not the same cleMission.

Well, from view1 I can set a variable in view2, is it correct ?

in view1 just before pushing view2, i can do this :

view2 *myView2 = [[view2 alloc]initWithNibName:nil bundle:nil];

myView2.cleMission = cleMission;

So in view2, if cleMission is declared in the interface, I can retrieve the value in cleMission.

Is it correct ?

[RLScott]

When you say "cleMission" without any qualifiers, then it refers to either a temporary variable or an instance variable of the class in which the code occurs. Since I did not see any temporary variable of that name in your code, I assume that it refers to an instance variable of the class in which the code resides.

When you say

pointControle.cleMission = @"456";

you are setting the instance variable of pointControle (using the setter for that variable). And pointControle is itself an instance of the class pointsControleController. (By the way, it is good practice to name your classes starting with an upper case letter and instances of objects starting with a lower case letter.)

The code that you said was giving you the problem was

pointControle.cleMission = cleMission;

which occurred in the implementation of your detailMissionController class. Therefore the "cleMission" referred to on the right hand side of the equal sign must be the cleMission instance variable of a detailMissionController object. This is certainly not the same thing as the "cleMission" that is being set in

pointControle.cleMission = @"456";

so that is why I said they are not the same cleMission.

You need to have a clear idea of what an instance variable is. I recommend "Programming in Objective C" by Kochran. It is a very good book, even if you don't know C very well.