How to clear UITextView... for real

Question

I'm ashamed to admit that I don't know how to clear a UITextView.

By clearing, I mean leaving its text blank and removing all of its attributes. I thought setting it to nil would be enough, but the attributes of the first character remain there, silently waiting until I type again to be added.

For example, the following code has a vanilla UITextView that can be cleared on double tap (doubleTapAction:). When loaded, I add a custom attribute that should also be removed when the UITextView is cleared.

@implementation HPViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] initWithString:@"test"];
    [attributedString addAttributes:@{@"attribute" : @"value"} range:NSMakeRange(0, 1)];
    self.textView.attributedText = attributedString;
}

- (IBAction)doubleTapAction:(id)sender
{
    self.textView.text = nil;
    // Also tried:
    // self.textView.text = @"";
    // self.textView.attributedText = nil;
    // self.textView.attributedText = [[NSAttributedString alloc] initWithString:@""];
}

- (void)textViewDidChange:(UITextView *)textView
{
    NSLog(@"%@", textView.attributedText);
}

@end

Clearing the UITextView and then typing the letter "d" logs the following:

d{
    NSFont = "<UICTFont: 0x8a7e4e0> font-family: \"Helvetica\"; font-weight: normal; font-style: normal; font-size: 12.00pt";
    NSParagraphStyle = "Alignment 4, LineSpacing 0, ParagraphSpacing 0, ParagraphSpacingBefore 0, HeadIndent 0, TailIndent 0, FirstLineHeadIndent 0, LineHeight 0/0, LineHeightMultiple 0, LineBreakMode 0, Tabs (\n    28L,\n    56L,\n    84L,\n    112L,\n    140L,\n    168L,\n    196L,\n    224L,\n    252L,\n    280L,\n    308L,\n    336L\n), DefaultTabInterval 0, Blocks (null), Lists (null), BaseWritingDirection 0, HyphenationFactor 0, TighteningFactor 0, HeaderLevel 0";
    attribute = value;
}

My custom attribute is still there!

Is this a bug or expected behaviour?

Answer 1

This awful hack does the trick:

self.textView.text = @"Something, doesn't matter what as long as it's not empty";
self.textView.text = @"";

Still, it would be nice to confirm if this is a bug or expected behaviour. I couldn't find anything in the documentation about it.

Answer 2

textView.text=@"";
[textView insertText:@""];

try this!

Answer 3

You have to manually reset font, text color etc. to your default values. Setting attributedText always sets the UITextView's "global" attributes to those of the first letter in the attributed string.

Answer 4

In my app I was seeing poor performance from the hack suggested by hpique:

self.textView.text = @"Something, doesn't matter what as long as it's not empty";
self.textView.text = @"";

The first line forces the UITextView to layout everything again. This is costly if the UITextView is used in a reused cell (in a UITableView for example).

In iOS 8 and later I found it much more performant with the following reset method on my UITextView subclass:

- (void)reset
{    
    self.text = nil;
    self.font = nil;
    self.textColor = nil;
    self.textAlignment = NSTextAlignmentLeft;
}

Answer 5

There is one property which can be useful in this situation. It's typingAttributes.

let textView = UITextView()
let attributes: [NSAttributedString.Key: Any] = [
    .font: UIFont.systemFont(ofSize: 16, weight: .regular),
    .foregroundColor: UIColor.black,
]
textView.typingAttributes = attributes