UITextField validation for email, password, name

Question

I am developing a register functionality in my app. I have some UITextFields like Email, password, username, first name.... and I want to validate them before I make the request to the server with the information. Now I validate them when I close the keypad doing this:

  -(BOOL) textFieldShouldReturn:(UITextField *)textField{

          if (textField == emailTextField)
        {
            if(emailTextField.text.length > 5){
                if(![self validateEmailWithString:emailTextField.text])
                {
                    // user entered invalid email address
                    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error"
 message:@"Enter a valid email address." delegate:self cancelButtonTitle:nil otherButtonTitles:@"OK", nil];
                    [alert show];
                    return NO;
                    //email.text=@"";
                } else {
                    [self.emailDelegate sendEmailForCell:emailTextField.text];
                    [textField resignFirstResponder];
                    return YES;

                }
            } else {
                UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error" message:@"Email address too Short" delegate:self cancelButtonTitle:nil otherButtonTitles:@"OK", nil];
                [alert show];

                return NO;
            }
        }
        return YES;
    }


    - (BOOL) validateEmailWithString:(NSString *)emailStr
    {
       NSString *emailRegex = @"[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,4}";
        NSPredicate *emailTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", emailRegex];
             return [emailTest evaluateWithObject:emailStr];
    }

But, when I do not close the keyPad with textFieldShouldReturn method I can not validate the UITextField where I am typing. I mean, when I click on the next UITextField before I press return key in the keypad I can type in the next UITextField and textFieldShouldReturn never has been called.

So, I guess I should use this method - (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string but I do not want to show to the user that it is an invalid email(or pass, or whatever) every time he types a letter.

So, my question is How could I manage this validation when the user stops typing letters in the keyboard but before he close the keypad?

Another question. Could I store in a variable the Boolean of this method shouldChangeCharactersInRange?

Thank you

rmaddy · Accepted Answer · 2013-11-05T22:59:03.970

2

Do the validation in the textFieldDidEndEditing: delegate method. This is called anytime the focus leaves a text field.

You could even do it in the textFieldShouldEndEditing: delegate method. If it's not valid you can return NO and the user won't be able to leave the invalid text field.

edited Nov 05 '13 at 22:59

answered Nov 05 '13 at 22:53

rmaddy

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But, with `textFieldShouldBeginEditing` How can't the user be able to leave that textfield? I have tried with this method http://stackoverflow.com/questions/7707906/how-to-check-if-uitextfields-text-is-valid-email, and it does not work – croigsalvador Nov 05 '13 at 22:58
@RoxeeMan Oops - that was a copy/paste error. I fixed the answer - it was supposed to be `ShouldEnd`, not `ShouldBegin`. Thanks. – rmaddy Nov 05 '13 at 22:59
I wanted to say with `shouldChangeCharactersInRange ` like in my link. When I try that it does not work.I do not know what to do the returned variable. Or how to manage it. Now, I am going to try to show up a valid or invalid label. When I leave the `UITextField` by `textFieldDidEndEditing` or `textFieldShouldEndEditing ` But I would like yo know how to use `shouldChangeCharactersInRange` – croigsalvador Nov 05 '13 at 23:07
Thank you for your answer. It is one of the bests ways to do it for me – croigsalvador Nov 05 '13 at 23:42

UITextField validation for email, password, name

1 Answers1