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

Understanding multiple managed object context


In multiple managed object context concept, we make several instances of managed object context and each instance works independently without having knowledge of what modifications are implemented in other instances. In order to keep all instances informed of different modifications performed in each context, a notification is broadcasted by a managed object context when any save or delete operation is performed on it. Like, if a managed object context completes a save operation, it broadcasts an NSNotification with the NSManagedObjectContextDidSaveNotification key.

The benefit of this notification is that any managed object context that listens to the notification NSManagedObjectContextDidSaveNotification can update its contents by invoking the method mergeChangesFromContextDidSaveNotification:. This method updates the contents of managed object context (with the managed object context that broadcasted the notification) and will also notify...