Truncate UILabel in specific location

Question

I use a table view to show a list of books, where each cell has a UILabel that shows the book\'s name and another UILabel the shows the book\'s aut

Answer 1

Edit: Generalized the solution to work with any "truncation location" string. Previous version only truncated at instance of string @" +". Edit allows you to define where you want the truncation to happen.

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I took my answer from this question (which was an answer modified from the answer on this site) and tailored it to fit your needs. Create a new NSString interface where you can send your string to be custom-truncated.

NOTE: This solution is for iOS 7+ only. To use in iOS 6, use sizeWithFont: instead of sizeWithAttributes: in the NSString+TruncateToWidth.m file.

NSString+TruncateToWidth.h

@interface NSString (TruncateToWidth)
- (NSString*)stringByTruncatingAtString:(NSString *)string toWidth:(CGFloat)width withFont:(UIFont *)font;
@end

NSString+TruncateToWidth.m

#import "NSString+TruncateToWidth.h"

#define ellipsis @"…"

@implementation NSString (TruncateToWidth)

- (NSString*)stringByTruncatingAtString:(NSString *)string toWidth:(CGFloat)width withFont:(UIFont *)font
{
    // If the string is already short enough, or 
    // if the 'truncation location' string doesn't exist
    // go ahead and pass the string back unmodified.
    if ([self sizeWithAttributes:@{NSFontAttributeName:font}].width < width ||
        [self rangeOfString:string].location == NSNotFound)
        return self;

    // Create copy that will be the returned result
    NSMutableString *truncatedString = [self mutableCopy];

    // Accommodate for ellipsis we'll tack on the beginning
    width -= [ellipsis sizeWithAttributes:@{NSFontAttributeName:font}].width;

    // Get range of the passed string. Note that this only works to the first instance found,
    // so if there are multiple, you need to modify your solution
    NSRange range = [truncatedString rangeOfString:string];
    range.length = 1;

    while([truncatedString sizeWithAttributes:@{NSFontAttributeName:font}].width > width 
           && range.location > 0)
    {
        range.location -= 1;
        [truncatedString deleteCharactersInRange:range];
    }

    // Append ellipsis
    range.length = 0;
    [truncatedString replaceCharactersInRange:range withString:ellipsis];

    return truncatedString;
}

@end

Using it:

// Make sure to import the header file where you want to use it
myLabel.text = [@"Benjamin Walker Jackson + 2 authors" stringByTruncatingAtString:@" +" toWidth:myLabel.frame.size.width withFont:myLabel.font];
// Sample Result: Benjamin Walte... + 2 authors