Core Foundation (also called CF) is a
C application programming interface
An application programming interface (API) is a way for two or more computer programs to communicate with each other. It is a type of software interface, offering a service to other pieces of software. A document or standard that describes how t ...
(API) written by Apple for its operating systems, and is a mix of low-level routines and
wrapper function
A wrapper function is a function (another word for a ''subroutine'') in a software library or a computer program whose main purpose is to call a second subroutine or a system call with little or no additional computation. Wrapper functions are ...
s. Most Core Foundation routines follow a certain naming convention that deal with opaque objects, for example CFDictionaryRef for functions whose names begin with CFDictionary, and these objects are often
reference counted (manually) through
CFRetain and
CFRelease. Internally, Core Foundation forms the base of the types in the
Objective-C
Objective-C is a general-purpose, object-oriented programming language that adds Smalltalk-style messaging to the C programming language. Originally developed by Brad Cox and Tom Love in the early 1980s, it was selected by NeXT for its NeXTS ...
standard library and the
Carbon API.
The most prevalent use of Core Foundation is for passing its own primitive types for data, including raw
byte
The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable uni ...
s,
Unicode strings,
numbers,
calendar date
A calendar date is a reference to a particular day represented within a calendar system. The calendar date allows the specific day to be identified. The number of days between two dates may be calculated. For example, "25 " is ten days after "1 ...
s, and
UUIDs, as well as collections such as
arrays
An array is a systematic arrangement of similar objects, usually in rows and columns.
Things called an array include:
{{TOC right
Music
* In twelve-tone and serial composition, the presentation of simultaneous twelve-tone sets such that the ...
,
set
Set, The Set, SET or SETS may refer to:
Science, technology, and mathematics Mathematics
*Set (mathematics), a collection of elements
*Category of sets, the category whose objects and morphisms are sets and total functions, respectively
Electro ...
s, and
dictionaries
A dictionary is a listing of lexemes from the lexicon of one or more specific languages, often arranged alphabetically (or by radical and stroke for ideographic languages), which may include information on definitions, usage, etymologies ...
, to numerous macOS
C routines, primarily those that are
GUI-related. At the operating system level Core Foundation also provides standardized application preferences management through
CFPropertyList,
bundle handling,
run loops,
interprocess communication through
CFMachPort and
CFNotificationCenter, and a basic
graphical user interface message dialog through
CFUserNotification.
Other parts of the API include utility routines and wrappers around existing APIs for ease of use. Utility routines perform such actions as
file system and
network
Network, networking and networked may refer to:
Science and technology
* Network theory, the study of graphs as a representation of relations between discrete objects
* Network science, an academic field that studies complex networks
Mathematic ...
I/O through
CFReadStream,
CFWriteStream, and
CFURL and
endianness translation (Byte Order Utilities). Some examples of wrapper routines include those for Core Foundation's wrapper routines for Unix sockets, the CFSocket API.
Some types in Core Foundation are "toll-free bridged", or interchangeable with a simple cast, with those of their
Foundation Kit counterparts. For example, one could create a
CFDictionaryRef Core Foundation type, and then later simply use a standard C cast to convert it to its Objective-C counterpart,
NSDictionary *, and then use the desired Objective-C methods on that object as one normally would.
Core Foundation has a plug-in model () that is based on the Microsoft
Component Object Model.
Open source availability
Apple used to release most of CF as an
open-source
Open source is source code that is made freely available for possible modification and redistribution. Products include permission to use the source code, design documents, or content of the product. The open-source model is a decentralized sof ...
project called CFLite that can be used to write cross-platform applications for macOS,
Linux, and
Windows.
A third-party open-source implementation called OpenCFLite extends the Apple CFLite for building on 32-bit
Windows and
Linux environments. It is maintained by one of the
WebKit developers, but was stalled by 2015. The karaoke platform KJams maintains a fork since 2017. This version, by its programmer David M. Cotter, supports 64-bit systems and has a CFNetwork implementation with
LibreSSL-based TLS. A fork of OpenCFLite was created by Grant Erickson (an original collaborator with Brent Fulgham on the SourceForge version) in 2021 with a companion port of the
CFHost portion of CFNetwork, as OpenCFNetwork.
The Swift Corelib Foundation, a fallback version of the
Foundation Kit for the Swift programming language for non-Apple platforms, contains a near-full version of the Core Foundation released under
Apache License 2.0.
GNUstep includes a version of the Core Foundation called "libs-corebase".
See also
*
GLib
GLib is a bundle of three (formerly five) low-level system libraries written in C and developed mainly by GNOME. GLib's code was separated from GTK, so it can be used by software other than GNOME and has been developed in parallel ever sinc ...
– the GNOME equivalent
References
External links
Core Foundation referenceat
Apple Developer
Apple Developer (formerly Apple Developer Connection) is Apple Inc.'s website for software development tools, application programming interfaces (APIs), and technical resources. It contains resources to help software developers write software for ...
OpenCFLiteat SourceForge
CFLite including CFNetworkworks in 64bit, uses LibreSSL (TLS 1.1, 1.2)
{{macOS
MacOS APIs