Uniform Type Identifiers

Overview

The Uniform Type Identifiers framework provides a collection of common types that map to MIME and file types. Use these types in your project to describe the file types in your app. These descriptions help the system properly handle file storage formats or in-memory data for transfer — for example, transferring data to or from the pasteboard. The identifier types can also identify other resources, such as directories, volumes, or packages.

Explicitly specify relationships between types by marking them as subtypes of other types. For example, the type UTTypePNG has the identifier public.png and is a subtype of UTTypeImage (public.image). UTTypeImage is in turn a subtype of both of the following:

• UTTypeContent (public.content), which implies the type can be a document

• UTTypeData (public.data), which implies the type is representable as a byte stream

Topics

Essentials

• Defining file and data types for your app
• System-declared uniform type identifiers

Uniform type identifiers

• UTType
• UTTagClass
• UTTypeReference

Reference

• UniformTypeIdentifiers Constants