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

Updating the stock


The implementation file of the AddProductController class (AddProductController.m) is modified to save the information of the product sold to the selected customer. Not only will the implementation file save the information of the product sold but, will also update the stock; the quantity of the product sold will be reduced from the inventory, that is, from the stock maintained in the MasterProduct entity. For example, if the initial quantity of Milk is 100 bottles (in the MasterProduct entity) and three bottles are sold to the customer, the quantity of the product left in the MasterProduct entity will be 97 bottles. Only the statements that are highlighted are added to the file and rest of the code is same as we saw in Chapter 8, Entering, Saving, Listing, and Deleting the Records of the Products Sold to the Customers:

// AddProductController.m
// prob
#import "AddProductController.h"
@implementation AddProductController
@synthesize newitemname, newquantity, newprice...