About this Book

This book is intended for intermediate-level iOS developers who know their way around Xcode and have built a few apps already. This allows me to provide instructions in a terse, tutorial-like style, as readers of my blog, cocoanetics.com, have come to appreciate. By focusing on a more experienced audience, I don’t have to waste your time with iOS development basics that are well covered in other books.

Roadmap

The topic of barcodes serves as the common thread running through the chapters of this book, but you can dive into specific chapters to learn about particular technologies. Here’s a quick overview of what you will find in each of the chapters.

Chapter 1 introduces you to the barcode types that are natively supported starting with iOS 7. You’ll become a barcode guru and be able to hold your own in any conversation about barcodes, their promises, and their limitations. If you like a good story, flip to appendix A, which recounts the curious history of the mother of all barcodes: the UPC.

Chapter 2 gives you a solid introduction to AV Foundation media capture. You’ll become familiar with the components of this framework, which we’ll use to build a camera app.

Chapter 3 introduces you to the metadata detectors for scanning barcodes, building on the camera preview from chapter 2. At this point, you’ll have a reusable barcode scanner that you can employ in all your apps.

Chapter 4 deals with Apple’s main reason for pushing forward with barcode support in iOS: Passbook. You’ll learn how to generate Passbook tickets with Ruby and how to validate them in an iOS app without the need for server infrastructure.

Chapter 5 looks at how you can generate your own barcodes for display on devices and how you can print them to physical media via AirPrint. You’ll learn about the use of Core Image for generating QR Codes and BarCodeKit for all kinds of 1D barcodes.

Chapter 6 dives into retrieving metadata for scanned barcodes, in particular how to use NSURLSession for creating a web service wrapper. The second half of this chapter is about creating a custom NSURLProtocol and how to stub network requests for unit testing without the need to call an actual server over the internet.

Chapter 7 then rounds out the book by adding contextual information about the user who’s scanning barcodes. Core Location and iBeacons let you magically adapt your app’s UI to your user’s needs.

Three appendixes provide additional background and other useful information.

Code conventions and downloads

All source code in listings or in text is in a fixed-width font like this to separate it from ordinary text. Code annotations accompany many of the listings, highlighting important concepts. In some cases, numbered bullets link to explanations that follow the listing.

Source code for all working examples in this book is available for download from the publisher’s website at www.manning.com/BarcodeswithiOS.

Author Online

Purchase of Barcodes with iOS includes free access to a private web forum run by Manning Publications, where you can make comments about the book, ask technical questions, and receive help from the author and from other users. To access the forum and subscribe to it, point your web browser to www.manning.com/BarcodeswithiOS. This page provides information on how to get on the forum once you are registered, what kind of help is available, and the rules of conduct on the forum.

Manning’s commitment to our readers is to provide a venue where a meaningful dialogue between individual readers and between readers and the author can take place. It is not a commitment to any specific amount of participation on the part of the author, whose contribution to the book’s forum remains voluntary (and unpaid). We suggest you try asking the author some challenging questions, lest his interest stray!

The Author Online forum and the archives of previous discussions will be accessible from the publisher’s website as long as the book is in print.