Replacement for deprecated sizeWithFont: in iOS 7?

I believe the function was deprecated because that series of

NSString+UIKit

functions
(

sizewithFont:...

,
etc) were based on the

UIStringDrawing

library,
which wasn't thread safe. If you tried to run them not on the main thread (like any other

UIKit

functionality),
you'll get unpredictable behaviors. In particular, if you ran the function on multiple threads simultaneously, it'll probably crash your app. This is why in iOS 6, they introduced a the

boundingRectWithSize:...

method
for

NSAttributedString

.
This was built on top of the

NSStringDrawing

libraries
and is thread safe.

If you look at the new

NSString

boundingRectWithSize:...

function,
it asks for an attributes array in the same manner as a

NSAttributeString

.
If I had to guess, this new

NSString

function
in iOS 7 is merely a wrapper for the

NSAttributeString

function
from iOS 6.

On that note, if you were only supporting iOS 6 and iOS 7, then I would definitely change all of your

NSString

sizeWithFont:...

to
the

NSAttributeString

boundingRectWithSize

.
It'll save you a lot of headache if you happen to have a weird multi-threading corner case! Here's how I converted

NSString

sizeWithFont:constrainedToSize:

:

What used to be:

NSString *text = ...;
CGFloat width = ...;
UIFont *font = ...;
CGSize size = [text sizeWithFont:font
constrainedToSize:(CGSize){width, CGFLOAT_MAX}];

Can be replaced with:

NSString *text = ...;
CGFloat width = ...;
UIFont *font = ...;
NSAttributedString *attributedText =
[[NSAttributedString alloc] initWithString:text
attributes:@{NSFontAttributeName: font}];
CGRect rect = [attributedText boundingRectWithSize:(CGSize){width, CGFLOAT_MAX}
options:NSStringDrawingUsesLineFragmentOrigin
context:nil];
CGSize size = rect.size;

Please note the documentation mentions:

In iOS 7 and later, this method returns fractional sizes (in the size component of the returned

CGRect

);
to use a returned size to size views, you must use raise its value to the nearest higher integer using the ceil function.

So to pull out the calculated height or width to be used for sizing views, I would use:

CGFloat height = ceilf(size.height);
CGFloat width  = ceilf(size.width);