How do I limit characters in UITextView ?

Question

I have been looking for solutions and found the following piece of code. But I do not know how to use it, unfortunately.

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)string {
        NSUInteger newLength = [textField.text length] + [string length] - range.length;
        return (newLength > 25) ? NO : YES;
    }

Just for testing purposes I set up an IBACTION

-(IBAction)checkIfCorrectLength:(id)sender{
    [self textView:myTextView shouldChangeTextInRange: ?? replacementText: ?? ];

}

What do I pass for shouldChangeTextInRange and replacementText ? Or am I getting it completely wrong ?

Answer 1

Calling textView:shouldChangeTextInRange:replacementText: from checkIfCorrectLength: doesn't make sense. If you want to test the length from multiple methods, factor the test out into its own method:

- (BOOL)isAcceptableTextLength:(NSUInteger)length {
    return length <= 25;
}

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)string {
    return [self isAcceptableTextLength:textField.text.length + string.length - range.length];
}

-(IBAction)checkIfCorrectLength:(id)sender{
    if (![self isAcceptableTextLength:self.textField.text.length]) {
        // do something to make text shorter
    }
}