iOS Enabling an uibarbuttonitem when at least one char is written in a uitextfield

[franium]

Hi,

I would to enable the done button on the navbar (in a modal view) when the user write at least a char in a uitextfield. Using textFieldDidEndEditing: enables the button when the previous uitextfield resigns first responder (so with the zero chars in the current uitextfield). textFieldShouldBeginEditing: is called when the textfield becomes the first responder.
The solution could be

-(BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string

but neither

 [self.navigationItem.rightBarButtonItem setEnabled:YES];

or

[doneButton setEnabled:YES]; //doneButton is an IBOutlet tied to my Done UIBarButtonItem in IB

work.
Any ideas?
Thanks,

Fran

 

[forum user]

delegates are setup for the navbar and the button?

- Olaf

 

[franium]

delegates are setup for the navbar and the button?

- Olaf

It's strange... I've added a property for doneButton (and synthesize) and it worked, then I remove the property, coming back to the old code and it works also so. But now I've another problem. This code:

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
	if (textField == password) {
		if (textField.text.length > 0) {
			doneButton.enabled = YES;
		} else {
			doneButton.enabled = NO;
		}
	}
	return YES;
}

enables the button when the text length is >0, but it disables the button when the chars are 0 and 2.
I don't understand this behaviour.

 

[franium]

It's strange... I've added a property for doneButton (and synthesize) and it worked, then I remove the property, coming back to the old code and it works also so. But now I've another problem. This code:

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
	if (textField == password) {
		if (textField.text.length > 0) {
			doneButton.enabled = YES;
		} else {
			doneButton.enabled = NO;
		}
	}
	return YES;
}

enables the button when the text length is >0, but it disables the button when the chars are 0 and 2.
I don't understand this behaviour.

I resolved with this check

if (textField.text.length >= 0) {
			doneButton.enabled = YES;
		} 
		if (string.length == 0 && textField.text.length == 1) {
			doneButton.enabled = NO;
		}

 

[ulbador]

delegates are setup for the navbar and the button?

- Olaf

This!

The prior code wasn't working because you didn't set the delegate for your nav bar to your class. By manually connecting your button to an outlet, you basically bypassed this (badly)

 

[franium]

This!

The prior code wasn't working because you didn't set the delegate for your nav bar to your class. By manually connecting your button to an outlet, you basically bypassed this (badly)

Oh... thanks... now I've understood