How to render text with clickable hyperlinks where you can control the action for click?

Answer 1

This might sound complicated but basically all the IM apps in the appstore (over 30 of them) have this functionality where a user can send an IM containing a URL and the receiving end can click on it and open the page in an in-app browser.

Yet what you want are custom callbacks, so this is a different functionality. They may be using UITextViews.

You'll probably have to write the code yourself, e.g. text rendering and link detection, or modify TTStyledTextLabel (which, in either case, looks like a good place to start). I do something similar and I just create UIButtons over any links. For link detection code check out Adium's source.

Answer 2

As far as I know you cannot assign ALL url to a custom action.

I gave you directions in your other SO question, so I'm a bit puzzled as to why you haven't read the source I linked to because it answered this exact question. TTURLMap supports catch-alls via the "-from:toViewController:selector" method. For example:

[map from:@"*" toViewController:[ViewController class]
        selector:@selector(someHandler:)];

I'd understand the confusion if you were dealing with a complete undocumented library, but the Three20 library is very well documented to the point of including sample applications that do exactly what you're after.