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

Storing the image of the MasterProduct


For storing the image of the master product, we will be assigning a special data type to the image attribute of the MasterProduct entity. That special data type is Transformable data type. So, let us have an idea of that data type before we move further.

Transformable data type

The Transformable data type is a special data type that allows us to create attributes based on an Objective-C class (custom objects). This data type is heavily used for storing instances of UIImage, UIColor, and so on. As the information stored in the persistent store has to be in the form of NSData instance, while using Transformable data type, we need to create Value Transformers to convert the custom object (information in attribute of Transformable data type) into an instance of NSData (before storing in the persistent store) and to convert the instance of NSData back to custom object while retrieving from the persistent store.

The Value Transformer Name: field

In this field...