Ayub Ayub - 26 days ago 13
Objective-C Question

disable button when textfields are empty

hi im a beginner to programming and have been stuck on this task for ages and seem to be getting nowhere.

basically i have several textfields that generates the input information on a different page when the user presses a button. i would like the button to be disabled until all text fields are filled with information.

so far i have this:

- (void)textFieldDidEndEditing:(UITextField *)textField
{
// make sure all fields are have something in them

if ((textfbookauthor.text.length > 0)&& (textfbookedition.text.length > 0)&& (textfbookplace.text.length > 0)&& (textfbookpublisher.text.length > 0) && (textfbookpublisher.text.length > 0) && (textfbooktitle.text.length > 0) && (textfbookyear.text.length > 0)) {
self.submitButton.enabled = YES;
}
else {
self.submitButton.enabled = NO;
}
}


the problem is the 'submitButton' is coming up with an error, what needs to go in its place?
i tried to put my button 'bookbutton'in it instead but its not working.

this is my function for the 'generate' button

-(IBAction)bookbutton:(id)sender;
{
NSString* combinedString = [NSString stringWithFormat:
@"%@ %@ %@.%@.%@:%@.",
textfbookauthor.text,
textfbookyear.text,
textfbooktitle.text,
textfbookedition.text,
textfbookplace.text,
textfbookpublisher.text];
BookGenerate*bookg = [[BookGenerate alloc] init];
bookg.message = combinedString;
bookg.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
[self presentModalViewController:bookg animated:YES];
[BookGenerate release];
}


if anybody knows how i can make it work or what i need to add please help.

thanks in advance

Answer

Make an Outlet for every UITextField and create an IBAction in your .h:

IBOutlet UITextField *textField1;
IBOutlet UITextField *textField2;
IBOutlet UITextField *textField3;
IBOutlet UIButton *button

- (IBAction)editingChanged;

Connect all the outlets and connect the IBAction to every textfield with editingChanged:

 - (IBAction)editingChanged {
    if ([textfield1.text length] != 0 && [textfield2.text length] != 0 && [textfield3.text length] != 0) {
         [button setEnabled:YES];
     }
     else {
         [button setEnabled:NO];
     }
 }

Note that you can also use [textfield.text isEqualToString:@""] and put a ! in front of it (!means 'not') to recognize the empty textField, and say 'if the textField is empty do...'

And:

- (void)viewDidLoad {
    [super viewDidLoad];
    [button setEnabled:NO];
}
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