The Core iOS Developer’s Cookbook, Fifth Edition

Recipe: Working with Uniform Type Identifiers

Uniform Type Identifiers (UTIs) represent a central component of iOS information sharing. You can think of them as the next generation of MIME types. UTIs are strings that identify resource types such as images and text. UTIs specify what kind of information is being used for common data objects. They do this without relying on older indicators, such as file extensions, MIME types, or file-type metadata such as OSTypes. UTIs replace these items with a newer and more flexible technology.

UTIs use a reverse-domain-style naming convention. Common Apple-derived identifiers look like this: public.html and public.jpeg. These refer, respectively, to HTML source text and JPEG images, which are both specialized ...