AutoLayout + RTL + UILabel text alignment

Question

I\'m finally getting round to wrestling with Auto Layout and can\'t seem to figure out how to get right-to-left (RTL) support to work the way I\'d expect/want...

I h

Answer 1

This function helped me out

-(void)fnForWritingDirection:(UILabel*)label textFor:(NSString *)stringForText{

    NSMutableAttributedString* attrStr = [[NSMutableAttributedString alloc] initWithString: [stringForText stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];

    NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];

    [paragraphStyle setBaseWritingDirection:NSWritingDirectionRightToLeft];

    [attrStr addAttribute:NSParagraphStyleAttributeName value:paragraphStyle range:NSMakeRange(0, [attrStr length])];

    label.attributedText=attrStr;

}

Answer 2

Follow up from Ken's answer

Setting textAlignment to NSTextAlignmentNatural is not possible on UILabel, it will result in an exception getting thrown:

Terminating app due to uncaught exception 'NSInvalidArgumentException',
reason: 'textAlignment does not accept NSTextAlignmentNatural'

It does work when using attributed text and this can be set in Interface Builder as shown:

However, it would appear that attributed text is not picked up when localising the storyboard.

To get around this I have left the UILabel configured as plain in Interface Builder and created an NSAttributedString with the label's text, set the alignment on the attributed string and assign it to the label's attributedText property:

-(void)viewDidLoad
{
    [super viewDidLoad];

    NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
    paragraphStyle.alignment = NSTextAlignmentNatural;

    NSMutableAttributedString *string = [[NSMutableAttributedString alloc] initWithString:self.lbl.text];
    [string addAttribute:NSParagraphStyleAttributeName
                   value:paragraphStyle
                   range:NSMakeRange(0, string.length)];

    self.lbl.attributedText = string;
}

This works fine in this simple case but I can see it falling over when you need more complex attributed string styling. But obviously in that case you'd probably just be using NSLocalizedString or equivalents when creating the NSAttributedString.

Answer 3

I think you don't want to use text alignment in this case, for a label.

You can just let the width be determined by intrinsicContentSize, and remove any width constraints on the label. You will achieve the desired effect of the label text aligned to the view.

For x axis, you only need this constraint between label and imageview: [imageview]-[label]

This is only a horizontal spacing constraint. No leading or trailing to superview.