Validate user input in textfield (minimum requirement)

[Andy Elliott]

In my AddItemViewController I have a text field for entering data (duh)
My challenge is even if no text is input to the field I can save a "blank" item to the dictionary.
Is there a way to require input before making "save" available?
Thanks for the help.

[Duncan C]

Originally Posted by Andy Elliott

In my AddItemViewController I have a text field for entering data (duh)
My challenge is even if no text is input to the field I can save a "blank" item to the dictionary.
Is there a way to require input before making "save" available?
Thanks for the help.

Sure.

Add a delegate of the UITextField.

Implement the UITextFieldDelegate method textField:shouldChangeCharactersInRange:replacemen tString:

This method gets called every time the user types a character or otherwise changes the text in the field.

In that routine, check to see if the text of the text field has a length of zero. IF yes, disable your save button. If no, enable the save button. (always return true unless you want to prohibit the change the user tries to make)

You might need to call yourself with performSelector:withObject:afterDelay:0 and check the text length in the method that you call, to give the system a chance to change the text of the text field after each edit. I haven't tried the approach I'm describing, but it should work.

[Andy Elliott]

Originally Posted by Duncan C

Sure.

Add a delegate of the UITextField.

Implement the UITextFieldDelegate method textField:shouldChangeCharactersInRange:replacemen tString:

This method gets called every time the user types a character or otherwise changes the text in the field.

In that routine, check to see if the text of the text field has a length of zero. IF yes, disable your save button. If no, enable the save button. (always return true unless you want to prohibit the change the user tries to make)

You might need to call yourself with performSelector:withObject:afterDelay:0 and check the text length in the method that you call, to give the system a chance to change the text of the text field after each edit. I haven't tried the approach I'm describing, but it should work.

I've added the ...shouldChangeCharactersInRange method... and it works.
As an example !([newString length] > 6); limits character to six

Would you explain how to have the code NOT accept less than one or 0 prior to enabling the save button?
The second question is: how do I disable the save button to start with.
The code below is what I'm using.

-(IBAction) saveid)sender {
NSLog(@"Save pressed");
if (aTitle !=nil) {
[titleArray removeObject:aTitle];
self.aTitle = nil;
}


//create a new title dictionary for the new values
NSMutableDictionary* newTitle = [[NSMutableDictionary alloc] init];
[newTitle setValue:titleTextField.text forKey:NAME_KEY];
[newTitle setValue:titleDetailView.text forKey:TITLEINFO_KEY];

//add it to the master title array and release our reference
[titleArray addObject:newTitle];
[newTitle release];

NSSortDescriptor *nameSorter = [[NSSortDescriptor alloc] initWithKey:NAME_KEY ascending:YES selector:@selector(caseInsensitiveCompare];
[titleArray sortUsingDescriptors:[NSArray arrayWithObject:nameSorter]];
[nameSorter release];

[self dismissModalViewControllerAnimated:YES];

}
-(IBAction) cancelid)sender {
NSLog (@"Cancel pressed");
[self dismissModalViewControllerAnimated:YES];
}

[thomashw]

Create an IBOutlet for your save button and connect it in Interface Builder. In IB, I would disable it by default. Then in your code you can enable it once there are 6 or more characters.