Book Image

Core Data iOS Essentials

By : Bintu Harwani, B. M. Harwani
Book Image

Core Data iOS Essentials

By: Bintu Harwani, B. M. Harwani

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
About the Author
About the Reviewers

Implementing the methods of the NSFetchedResultsControllerDelegate protocol

The classes that are declared as delegate of the NSFetchedResultsControllerDelegate protocol have to implement its methods, as these methods take the necessary actions (like updating the table view) when some changes are applied to the managed object. Let us get an idea of all the four methods declared in the said protocol:

  • controllerWillChangeContent

  • controllerDidChangeContent

  • controller:didChangeObject

  • controller:didChangeSection

These four methods are defined in the protocol: NSFetchedResultsControllerDelegate. The fetched results controller monitors its managed object context and calls its delegates as changes are made to its context. These methods help in updating the table view or take other actions on the basis of modifications applied to the context.

The controllerWillChangeContent method

When the object managed by fetchedResultsController is modified, that is, if it is deleted, updated, or a new object is added...