Core IOS Services layer

Core Services layer

 

The Core Services layer provides access to several more system services that
most applications use. These services include
? iCloud: iCloud is a cloud-based storage service that gives you iOS
devices to share documents and applications and to share small bits of
data (such as preferences) across your multiple iOS devices.
? Automatic reference counting (ARC): ARC is the name of the new
Objective-C compiler as well as a runtime feature that enables memory
management within your program without you having to explicitly free
memory. ARC automatically keeps track of all references to an object
and then deletes the object when no references point to it. If you’re a
Java programmer, you’ll recognize that ARC is essentially the iOS version
of automatic memory management and garbage collections.
Apple’s development environment (Xcode) provides tools that help you
migrate from an older application that doesn’t use ARC to one that does.
? Block objects: Block objects are inline code along with associated data
that’s treated as a function.
Block objects are particularly useful as callbacks — such as to user
interface events or to thread events.
? Data protection: This is the capability to encrypt, lock, and unlock files
that an application needs to keep secret.
? File-sharing support: This enables applications to share files via iTunes
(version 9.0 and higher).
? Grand Central Dispatch: This is a concurrency-enabling mechanism
that enables programmers to define concurrent tasks, rather than create
threads directly, and then lets the system perform the tasks.
? In-App Purchase: This is the ability to purchase from vendors such as
iTunes directly from an app. In-App Purchase is implemented by a framework
known as the Store Kit.
? Core Data: Core Data is a framework for managing the lifecycle of persistent
objects. Core Data works well with SQLite, which is probably the
most widely used database on mobile devices. Core Data and its use of
SQLite..
The Core Services layer also provides a collection of frameworks for the
following:
? Managing the address book
? Supporting ads
? Providing high-performance access to networks
? Manipulating strings, bundles, and raw blocks
? Making use of location, media, motion, and telephony
? Managing documents
? Downloading newsstand content
? Managing coupons and passes
? Presenting thumbnail views of files
? Accessing social media accounts
? Purchasing from the iTunes store
? Programmatically determining the network configuration and access of a
device
The Core Services layer provides the object-oriented Foundation framework
that does the following:
? Defines the basic behavior of object.
? Provides management mechanisms.
? Provides object-oriented ways of handling primitive data types, such as
integers, strings and floating-point numbers, collections, and operating system
services.
The Cocoa Touch framework (see the section, "Cocoa Touch layer, and the Foundation framework make up the two key iOS development
components used by developers. Use all the other components on an
as-needed basis.
? JSON support: This service provides support for parsing and creating
JSON documents.