Professional iOS Network Programming: Connecting the Enterprise to the iPhone and iPad

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PROFESSIONAL

IOS NETWORK PROGRAMMING

INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xix

PART I UNDERSTANDING IOS AND ENTERPRISE NETWORKING

CHAPTER 1 Introducing iOS Networking Capabilities . . . . . . . . . . . . . . . . . . . . . . . . . . 3

CHAPTER 2 Designing Your Service Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

PART II HTTP REQUESTS: THE WORKHORSE OF IOS NETWORKING

CHAPTER 3 Making Requests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

CHAPTER 4 Generating and Digesting Payloads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

CHAPTER 5 Handling Errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

PART III ADVANCED NETWORKING TECHNIQUES

CHAPTER 6 Securing Network Traffi c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119

CHAPTER 7 Optimizing Request Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157

CHAPTER 8 Low-Level Networking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175

CHAPTER 9 Testing and Manipulating Network Traffi c . . . . . . . . . . . . . . . . . . . . . . . . .191

CHAPTER 10 Using Push Notifi cations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213

PART IV NETWORKING APP TO APP

CHAPTER 11 Inter-App Communication. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247

CHAPTER 12 Device-to-Device Communication with Game Kit . . . . . . . . . . . . . . . . . 267

CHAPTER 13 Ad-Hoc Networking with Bonjour . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281

INDEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .319

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PROFESSIONAL

iOS Network Programming

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PROFESSIONAL

iOS Network Programming

CONNECTING THE ENTERPRISE

TO THE IPHONE® AND IPAD®

Jack Cox

Nathan Jones

John Szumski

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Professional iOS Network Programming: Connecting the Enterprise to the iPhone® and iPad®

Published by

John Wiley & Sons, Inc.

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Indianapolis, IN 46256

www.wiley.com

Copyright © 2012 by John Wiley & Sons, Inc., Indianapolis, Indiana

Published simultaneously in Canada

ISBN: 978-1-118-36240-2

ISBN: 978-1-118-38223-3 (ebk)

ISBN: 978-1-118-41716-4 (ebk)

ISBN: 978-1-118-53385-7 (ebk)

Manufactured in the United States of America

10 9 8 7 6 5 4 3 2 1

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vendor mentioned in this book.

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ABOUT THE AUTHORS

JACK COX is a software developer, a systems architect, and the director at CapTech

Ventures, Inc., where he is responsible for the fi rm’s mobile software practice. He

has 30 years of experience in developing software for businesses of all sizes. He has

been involved in three startups, holds multiple patents, and frequently presents to

professional groups. He has a degree in computer science from Taylor University in

Upland, Indiana. Jack lives in Richmond, Virginia, with his wife and children. You

can get in touch with Jack on Twitter @jcox_mobile.

NATHAN JONES is a software engineer with expertise in iOS and experience in

mobile web technologies. He began his career in enterprise software consulting

and started exploring mobile development when Apple announced the capability

to develop third-party apps for the iPhone. He graduated with a bachelor of

science in business information technology with a concentration on decision

support systems from Virginia Polytechnic Institute and State University in

Blacksburg, Virginia. He currently resides in Richmond, Virginia with his wife,

Jennifer, and son, Bryson. When he isn’t working, writing, or playing with his

son, he enjoys golfi ng and is an avid runner. You can get in touch with Nathan on Twitter @

nathanhjones.

JOHN SZUMSKI is a software engineer and mobile consultant with expertise in

the iOS, Android, and mobile web platforms. He advises Fortune 500 companies

on user experience and technical design. He graduated with a bachelor of

science in computer science (with distinction) from the University of Virginia in

Charlottesville, Virginia. John lives with his fi ancée in Richmond, Virginia. You

can get in touch with John on Twitter @jszumski.

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ABOUT THE TECHNICAL EDITOR

JONATHAN TANG is a senior developer specializing in mobile applications at

CapTech Consulting. He has more than 10 years of development experience,

including programming touchscreen interfaces, medical devices, and iOS mobile

applications. Prior to CapTech, John worked as the primary software engineer at a

startup company that specializes in medical robotics. John received a bachelor of

science in biomedical engineering from Johns Hopkins University and a master

of science in electrical engineering from George Washington University.

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EXECUTIVE EDITOR

Carol Long

PROJECT EDITOR

Victoria Swider

TECHNICAL EDITOR

Jonathan Tang

PRODUCTION EDITOR

Kathleen Wisor

COPY EDITOR

San Dee Phillips

EDITORIAL MANAGER

Mary Beth Wakefi eld

FREELANCER EDITORIAL MANAGER

Rosemarie Graham

ASSOCIATE DIRECTOR OF MARKETING

David Mayhew

MARKETING MANAGER

Ashley Zurcher

BUSINESS MANAGER

Amy Knies

PRODUCTION MANAGER

Tim Tate

VICE PRESIDENT AND EXECUTIVE GROUP

PUBLISHER

Richard Swadley

VICE PRESIDENT AND EXECUTIVE

PUBLISHER

Neil Edde

ASSOCIATE PUBLISHER

Jim Minatel

PROJECT COORDINATOR, COVER

Katie Crocker

PROOFREADER

Nancy Carrasco

INDEXER

Johnna VanHoose Dinse

COVER DESIGNER

Ryan Sneed

COVER IMAGE

© pagadesign/iStockPhoto

CREDITS

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ACKNOWLEDGMENTS

I WANT TO THANK the principles, management, and coworkers at CapTech Ventures, especially

Vinnie Schoenfelder, for encouraging and supporting our effort to write this book. I want to extend

special thanks to Nathan Jones and John Szumski for being willing and faithful in this adventure to

complete our fi rst book. On behalf of Nathan, John, and myself, I want to thank Carol Long and

Victoria Swider at Wiley for tolerating and answering all our newbie questions.

To my wife and family, I extend thanks without number for putting up with all of the nights and

weekends of writing and the associated crankiness. Thank you for allowing me to fulfi ll this dream.

And most important, I extend thanks and praise to my savior, Jesus Christ, who, through His

grace and mercy, has blessed me with so much that I do not deserve. Without Him, I would be hope￾less and useless.

—Jack Cox

I WOULD LIKE TO THANK my lovely wife, Jennifer, and son, Bryson, for their continued support

and patience while working on this book. There are times when I saw more of Xcode than I saw of

you two, and those late nights and weekends weren’t easy on you guys. That didn’t go unnoticed,

thank you. I would also like to thank my parents for encouragement throughout the process, and

my dad, specifi cally, for teaching me to write my fi rst program. That planted the seed. I still have

that fl oppy disk, but I don’t think I have a drive to read it.

—Nathan Jones

I WOULD LIKE TO THANK my beautiful fi ancée, Caroline, for her understanding and support during

many late nights spent writing or editing. I also appreciate my extended family’s encouragement

through the entire publishing process.

—John Szumski

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CONTENTS

INTRODUCTION xix

PART I: UNDERSTANDING IOS AND ENTERPRISE NETWORKING

CHAPTER 1: INTRODUCING IOS NETWORKING CAPABILITIES 3

Understanding the Networking Frameworks 3

iOS Networking APIs 4

NSURLConnection 5

Game Kit 5

Bonjour 5

NSStream 6

CFNetwork 6

BSD Sockets 6

Run Loops 7

Run Loop Modes 8

Summary 8

CHAPTER 2: DESIGNING YOUR SERVICE ARCHITECTURE 9

Remote Façade Pattern 10

Example Façade Services 12

Example Façade Clients 15

Service Versioning 17

Example Versioned Services 18

Example Client Using Versioned Services 19

Service Locators 20

Summary 24

PART II: HTTP REQUESTS: THE WORKHORSE OF IOS NETWORKING

CHAPTER 3: MAKING REQUESTS 27

Introducing HTTP 28

Understanding HTTP Requests and Responses 29

URL Structure 30

Request Contents 31

Response Contents 33

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