Book Image

Core Data iOS Essentials

Book Image

Core Data iOS Essentials

Overview of this book

Core Data is the essential ingredient in data driven iOS apps. It's used for storing, retrieving, and manipulating application data in databases, XML, and binary formats. It's an essential component for iPhone, iPod Touch, and iPad apps.Core Data Essentials provides a clear, readable guide to the most useful aspects of Core Data. Built around a realistic example app, the book showcases the most important aspects of Core Data development in the context of a complete, functioning app written in Objective C.The book starts with a tour of how the app works. Then you'll see how to easily display data using the Table View. You'll learn how to develop an appropriate data model that fits the needs of your app, then implement that model as updatable data objects. You'll see how to update data and build relationships between objects and learn how Core Data can work with search, and how to provide your users with friendly data editing features.
Table of Contents (19 chapters)
Core Data iOS Essentials
Credits
About the Author
Acknowledgement
About the Reviewers
www.PacktPub.com
Preface
Appendix

Protocol


A protocol is not itself a class. Rather, it's an interface that declares methods. Only the methods are declared, that is, there is no body of the method defined in the protocol. The reason that format protocols are used for the delegation pattern is two fold:

  1. 1. The protocol acts as a documentation of the delegate interface and it allows for the compiler to check adherence.

  2. 2. At runtime you can interrogate an object in a single call to see if a protocol has been adopted rather than checking on a per method basis to see if an object will respond to a message.

The delegates are responsible for implementing the methods of the confirming protocol.

Implementing the Strategy pattern

To work with a protocol, we need to:

  1. 1. Define the protocol

  2. 2. Create the delegate property

  3. 3. Declare the protocol methods

Defining the protocol

A protocol is defined by using the @protocol compiler directive, combined with an @end directive. In between the two directives, we must declare the protocol method...