How to add a textfield to an NSMutableArray - ios

Question

I'm trying to present what was entered into a textfield into a nsmutable array that will later be displayed.
I think that the problem is in the -(void)viewDidLoad method but I included all of the code just in case. The catch is that I will be leaving this page and then returning to it after another piece of information is selected. As this happens, I need to keep track of EACH thing that was entered into the textfield. Thanks for any help!
#import "EnteringCoursesViewController.h"
#import "SelectRotationController.h"
#implementation EnteringCoursesViewController
#synthesize classField;
#synthesize indicatedClass;
#synthesize labelClassTitle;
#synthesize selectRotationController;
#synthesize classesEnteredTable;
- (IBAction)chooseType {
UIActionSheet *typeSheet = [[UIActionSheet alloc]
initWithTitle:#"Class types"
delegate:self
cancelButtonTitle:nil
destructiveButtonTitle:nil
otherButtonTitles:#"Core Class", #"Elective", nil];
[typeSheet showInView:self.view];
[typeSheet release];
}
- (void)actionSheet:(UIActionSheet *)typeSheet clickedButtonAtIndex:(NSInteger)buttonIndex
{
if (buttonIndex == 0) {
self.indicatedClass = classField.text;
NSString *indicatedString = indicatedClass;
NSString *greeting = [[NSString alloc]
initWithFormat:#"%# meets 6 times per rotation", indicatedString];
labelClassTitle.text = greeting;
labelClassTitle.hidden = NO;
[greeting release];
[indicatedClass release];
}
else if (buttonIndex == 1) {
self.indicatedClass = classField.text;
NSString *indicatedString = indicatedClass;
NSString *greeting = [[NSString alloc]
initWithFormat:#"%# meets 3 times per rotation", indicatedString];
labelClassTitle.text = greeting;
labelClassTitle.hidden = NO;
[greeting release];
[indicatedClass release];
}
}
- (IBAction)chooseFirstMeeting:(id)sender {
SelectRotationController *selectView = [[SelectRotationController alloc]
initWithNibName:#"SelectRotationController"
bundle:[NSBundle mainBundle]];
[selectView.navigationItem setTitle:#"First Period Day Choose"];
[self.navigationController pushViewController:self.selectRotationController animated:YES];
self.selectRotationController = selectView;
[selectView release];
}
- (IBAction)enteredClassText:(id)sender {
NSMutableArray *classesEntered = [[NSMutableArray alloc] init];
[classesEntered addObject:indicatedClass];
[classesEntered release];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
}
- (void)viewDidLoad {
self.navigationItem.hidesBackButton = YES;
[super viewDidLoad];
}
- (void)viewDidUnload {
[super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
- (void)dealloc {
[classField release];
[labelClassTitle release];
[indicatedClass release];
[selectRotationController release];
[classesEnteredTable release];
[super dealloc];
}
#end

Answer 1

If viewDidLoad is called "indicatedClass" is not yet initialised and therefore nil.
https://developer.apple.com/library/mac/#documentation/Cocoa/Reference/Foundation/Classes/NSMutableArray_Class/Reference/Reference.html
Important Raises an NSInvalidArgumentException if anObject is nil.
If you want to save that by leaving the view, add the addObject-Call in the viewDidUnload-method. Definitely you should check if the value is nil ;)
I dont see any alloc for your variable indicatedClass but an release!? It might be that the variable doesnt exists if viewDidUnload is calling.
EDIT
You init an NSMutableArray, add the object to this array and after that you released that object. Therefore the Data is away. You must save your array therewith you can use the content later. Keyword: NSUserDefaults ;)
Check also of nil values:
- (IBAction)enteredClassText:(id)sender {
if (indicatedClass != nil) {
NSMutableArray *classesEntered = [[NSMutableArray alloc] init];
[classesEntered addObject:indicatedClass];
[classesEntered release];
}
}
If the sender is an UILabel you can also use this snippet:
- (IBAction)enteredClassText:(id)sender {
if (sender.text != nil) {
NSMutableArray *classesEntered = [NSMutableArray arrayWithObject:sender.text];
// TODO: Save your array to NSUserDefaults...
}
}