Barcodes with iOS: Bringing together the digital and physical worlds

by Oliver Drobnik

Overview

Summary

Barcodes with iOS is the first and only book that comprehensively addresses barcode technology for the iOS developer. It offers an introduction to commonly used formats, such as ISBN and UPC codes, and provides real-world examples that teach you how to integrate code scanning and generation into your apps. This book consolidates information about applicable Apple frameworks in one place so you can quickly add native barcode support to your existing enterprise apps or start building new apps that help bring together the physical and digital worlds.

Purchase of the print book includes a free eBook in PDF, Kindle, and ePub formats from Manning Publications.

About the Technology

Barcodes are a universal way to track and share information, appearing on everything from cereal boxes to shop windows. Starting with iOS 7, Apple has added native features for building apps that scan, display, and print barcodes, eliminating the need for third-party libraries.

About the Book

Barcodes with iOS teaches you how to effectively use barcodes in your iOS apps. You'll master Apple's new barcode frameworks while you explore real-world examples that integrate code scanning and generation and metadata retrieval into your apps. Along the way, you'll pick up numerous best practices for bringing together the physical and digital worlds.

This book is written for readers with a working knowledge of Objective-C and iOS app development.

What's Inside

• Learn about all barcode formats supported by iOS
• Native barcode scanning with AV Foundation
• Using Core Image and BarCodeKit to produce a wide range of barcodes
• Printing to sheets and labels with AirPrint
• Retrieving metadata for products with NSURLSession and NSURLProtocol
• Harnessing context information from Core Location and iBeacons

About the Author

Oliver Drobnik is an independent consultant specializing in custom iOS and Mac development.

Table of Contents

1. Barcodes, iOS, and you 1
2. Media capture with AV Foundation 18
3. Scanning barcodes 48
4. Passbook, Apple's digital wallet 70
5. Generating barcodes 97
6. Getting metadata for barcodes 133
7. Putting barcodes in context 172

Appendices

1. History of the UPC 205
2. GTIN prefix ranges 212
3. GS1-128 application identifiers 217

Product Details

ISBN-13:	9781617292156
Publisher:	Manning
Publication date:	02/06/2015
Edition description:	1st Edition
Pages:	248
Product dimensions:	7.30(w) x 9.10(h) x 0.70(d)

About the Author

Oliver Drobnik is an independent consultant specializing in custom iOS and Mac development.

Table of Contents

Preface xi

Acknowledgments xiii

About this book xv

About the cover illustration xvii

1 Barcodes, iOS, and you 1

1.1 The evolution of barcodes 3

One dimension: laser 4

Two dimensions: CCD 5

Versatility is winning 6

Where are the bars'? 6

1.2 Barcode symbologies in iOS 6

ID barcodes in iOS 7

2D barcodes in iOS 13

So many choices: which barcode should I use ? 16

1.3 Summary 16

2 Media capture with AV Foundation 18

2.1 Introducing AV Foundation 19

2.2 Building a camera app 20

AV Foundation setup 22

Building the camera UI 24

Selecting capture devices 25

Media capture session 28

Showing live video preview 29

Authorizing camera access (or not) 32

Toggling the video light 34

Taking pictures to the camera roll 36

Supporting rotation of device and UI 39

Switching between camera devices 41

Implementing autofocus and lap-to-focus 44

2.3 Summary 46

3 Scanning barcodes 48

3.1 Metadata detection in AV Foundation 49

3.2 Building a QR Code scanner 49

Reusing camera code 51

Creating and configuring the metadata output 53

Wiring up the metadata objects' delegate 54

Creating a barcode scan delegate 55

Marking detected barcodes on preview 58

Building an optimal scanning UI 61

Tweaking capture device settings 65

Opening a scanned web address in Mobile Safari 67

3.3 Summary 68

4 Passbook Apple's digital wallet 70

4.1 Barcodes in Passbook 71

4.2 Producing digital passes for your users 72

Requesting a certificate for signing passes 72

Preparing signing certificates 76

Constructing passes 78

Pass creation takeaways 88

4.3 Validating passes 88

Building a ticket-verifier app 90

Reusing barcode scanner code 90

Serverless pass validation 92

Pass validation takeaways 94

5 Generating barcodes 97

5.1 Producing barcodes for display or print 98

Thoughts on barcode size 99

QR Code error correction 99

4.4 Summary 95

5 Generating barcodes 97

5.1 Producing barcodes for display or print 98

Thoughts on barcode size 99

QR Cock error correction 99

5.2 Generating 2D barcodes 100

Building a QR Code Builder app 101

Introducing Core Image 101

Project setup for Core Image 104

Generating QR Codes with Core Image 107

Copying the QR Code to the pasteboard 109

Private APIs for Aztec and PDF417 codes 111

Printing barcodes with AirPrint 112

Saving trees with the iOS Printer Simulator 114

Custom drawing with UIPrintPageRenderer 115

AirPrint paper selection 118

QR Code Builder app summary 118

5.3 Generating ID barcodes 119

Building a Serial Number Tag app 119

Introducing BarCodeKit 120

Adding BarCodeKit to your project 121

Setting up the Serial Number Tag app's UI 124

Generating ID barcodes with BarCodeKit 126

AirPrint and mil-feed printers 128

Serial Number Tag app summary 131

5.4 Summary 131

6 Getting metadata for barcodes 133

6.1 Modern networking with NSURLSession 134

File downloads with NSURISessionDownloadTash 135

Building a Music Collection app 137

Asynchronous Core Data updates 138

Presenting the barcode scanner modally 140

Using NSURLSessionDataTask to call RESTful web APIs 142

Authenticating API requests with OAuth 149

Adding DTOAuth to your project 151

Configuring the OAuth consumer 152

Implementing the UI for OAuth authorization 154

Connecting barcode scanning and metadata retrieval 156

6.2 Unit-testing network operations 159

Introducing NSUKLProtocol 159

Implementing a custom URL scheme with NSURLProtocol 160

Stubbing NSURLRequest responses with DTURLProtocolStub 163

Stubbing NSURLSession requests with DTURLProtocolStub 166

How to test asynchronous completion handlers 168

Shifting to test-driven development 169

6.3 Summary 170

7 Putting barcodes in context 172

7.1 Understanding multiple layers of context 173

7.2 Building a YardSale app 174

Creating the outside-the-store experience 176

Implementing the in-store user interface 181

7.3 Geofencing store locations 183

Introducing region monitoring 183

Monitoring an unlimited number of regions 184

Updating monitored regions based on user location 186

Notifying users when entering a monitored region 189

7.4 Enhancing the in-store UI with iBeacons 194

Introducing the iBeacon system 195

Beacon monitoring at a glance 196

Making any app emit an iBeacon 197

Determining distance to iBeacons with ranging 198

Adding an in-store barcode scanner 201

7.5 Summary 204

Appendix A History of the UPC 205

Appendix B GTIN prefix ranges 212

Appendix C GS1-128 application identifiers 217

Index 221