This is a subset of my CoreTextToy (https://github.com/schwa/CoreTextToy) project extracted out into its own github repo.

Specifically this code allows you to use (simple) HTML markup with UILabel.

Obligatory screenshots:

This code is licensed under the 2-clause BSD license ("Simplified BSD License" or "FreeBSD License") license. The license is reproduced below:

Copyright 2011 Jonathan Wight. All rights reserved.

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The master and develop branches require iOS 6.0 or higher with ARC.

This implements a "setMarkup:" method. Pass it HTML. This is the point of this library.

A value transformer capable of converting simple markup (a small subset of HTML) into a NSAttributedString.

Extension on UIFont to get a CTFont and to get bold/italic, etc variations of the font. Scans the font name to work out the attributes of a particular font.

This code is crude and effective - but needs to be tested on all iOS font names (especially the weirder ones).

UIWebViews are expensive to create and are pretty much overkill when all you need is a simple UILabel type class that shows static styled text.

TODO: Elaborate here (https://twitter.com/mattyohe/status/444320277812748288)

It uses a minimal subset of HTML. In fact don't think of it as pure HTML - think of it as just a convenient method for creating NSAttributedString.

Only a handful of tags are supported right now, but you can define your own quite easily.

UILabel isn't quite as configurable as CoreTextToy's label code. As such not all tags supported there are supported by this code. Go use CoreTextToy or NSHTMLTextDocumentType if you need image tags.

The quick way:

NSString *theMarkup = @"<b>Hello world</b>";
NSError *theError = NULL;
NSString *theAttributedString = [NSAttributedString attributedStringWithMarkup:theMarkup error:&theError];
// Error checking goes here.
theLabel.attributedString = theAttributedString

The quicker way:

NSString *theMarkup = @"<b>Hello world</b>";
[theLabel setMarkup:theMarkup];

For the long way, see "How do I add custom styles?"

If you dont like the built-in standard styles you can replace them or add new ones. The process is pretty straightforward:

// Here's the markup we want to put into our UILabel. Note the custom <username> tag
NSString *theMarkup = [NSString stringWithFormat:@"<username>%@</username> %@", theUsername, theBody];

NSError *theError = NULL;

// Create a transformer and set up the standard styling (that part is optional)
CMarkupTransformer *theTransformer = [[CMarkupTransformer alloc] init];
[theTransformer addStandardStyles];

// Create custom attributes for our new "username" tag
NSDictionary *theFormatDictionary = @{
    NSForegroundColorAttributeName: [UIColor blueColor],
    kMarkupFontNameMetaAttributeName: @"Helvetica",
    };
[self addFormatDictionary:theFormatDictionary forTag:@"username"];

// Transform the markup into a NSAttributedString
NSAttributedString *theAttributedString = [theTransformer transformMarkup:inMarkup baseFont:self.font error:&theError];

// Give the attributed string to the CCoreTextLabel.
self.label.attributedString = theAttributedString;