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iOS 11 Swift
P rogramming
C ookbook
SOLUTIONS & EXAMPLES FOR IOS APPS
Vandad Nahavandipoor
iOS 11 Swift Programming
Cookbook
Solutions and Examples for iOS Apps
Vandad Nahavandipoor
iOS 11 Swift Programming Cookbook
by Vandad Nahavandipoor
Copyright © 2018 Vandad Nahavandipoor. All rights reserved.
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2017-12-04: First Release
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978-1-491-99247-0
[LSI]
Table of Contents
Preface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix
1. Continuous Integration and Delivery. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1 Setting Up Xcode Server 2
1.2 Connecting Local Xcode to Xcode Server 3
1.3 Archiving Your Apps with Xcode Bots 6
1.4 Running Your Tests Automatically with Xcode Bots 12
1.5 Performing Analysis of Your Code Using Xcode Bots 17
1.6 Integrating GitHub Projects with Travis 20
1.7 Installing the Travis CLI 23
1.8 Running Your Unit Tests with Travis 25
1.9 Building and Archiving Your Project with Travis 27
1.10 Installing and Setting Up fastlane 33
1.11 Building Your Apps with fastlane 35
1.12 Testing Your Apps with fastlane 38
1.13 Enabling Slack Notifications in fastlane 40
1.14 Archiving Your Apps with fastlane 44
1.15 Uploading Your Apps to iTunes Connect with fastlane 46
2. Snapshot Testing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
2.1 Setting Up Snapshot Testing 50
2.2 Recording Snapshots 54
2.3 Specifying Tolerance in Snapshot Tests 58
2.4 Analyzing Snapshot Test Case Failures 60
2.5 Testing Table View Cell Snapshots 62
3. SiriKit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
3.1 Setting Up Your Project for Siri 65
iii
3.2 Defining an Intent Handler 71
3.3 Resolving Ambiguity in an Intent 78
3.4 Reporting Progress for Resolving an Intent 86
3.5 Handling an Intent 88
4. Measurements and Units. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
4.1 Converting Between and Working with Length Units 91
4.2 Working with and Switching Between Angle Units 93
4.3 Representing and Converting Between Durations of Time 94
4.4 Using and Working with Frequency Units 96
4.5 Working with and Using Power Units 98
4.6 Representing and Comparing Temperature Units 99
4.7 Working with and Converting Volume Units 100
5. Core Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
5.1 Designing Your Database Scheme 104
5.2 Writing Data to the Database 109
5.3 Reading Data from the Database 111
5.4 Searching for Data in the Database 114
5.5 Performing Background Tasks with Core Data 117
6. Swift and Cocoa Touch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
6.1 Extending Typed Arrays 121
6.2 Taking Advantage of Open Collection Ranges 123
6.3 Organizing Private Functions and Properties with Extensions 124
6.4 Defining Key Paths in Swift 127
6.5 Parsing from and to JSON with Swift 129
6.6 Handling Corner Cases in JSON Parsing with Swift 130
6.7 Partitioning Arrays into Segments 134
6.8 Setting Constraints on Extensions 136
6.9 Defining Object Requirements Through Protocols 138
6.10 Creating New Data Types by Combination 141
6.11 Adding Logic Through Protocols 143
6.12 Defining Constraints on Protocols 146
6.13 Handling Errors in Swift 148
6.14 Specifying Preconditions for Methods 149
6.15 Ensuring the Execution of Code Blocks Before Exiting Methods 151
6.16 Checking for API Availability 152
6.17 Creating Your Own Set Types 154
6.18 Conditionally Extending a Type 155
6.19 Optimizing Your Swift Code 157
6.20 Building Equality Functionality into Your Own Types 160
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6.21 Grouping switch Statement Cases Together 162
6.22 Looping Conditionally Through a Collection 163
6.23 Bundling and Reading Data in Your Apps 164
7. Xcode 9 and Interface Builder. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169
7.1 Changing Variable Names in the Current Scope 169
7.2 Utilizing Regular Expressions in Your Xcode Searches 171
7.3 Debugging Apps on an iOS Device Wirelessly 174
7.4 Making Sure UI Methods Run on the Main Thread 177
7.5 Creating a GitHub Repository for Your Project in Xcode 179
7.6 Synchronizing Your Code with GitHub Inside Xcode 181
7.7 Categorizing and Downloading Assets to Get Smaller Binaries 184
7.8 Exporting Device-Specific Binaries 187
7.9 Linking Separate Storyboards Together 188
7.10 Adding Multiple Buttons to the Navigation Bar 189
7.11 Showing the Header View of Your Swift Classes 190
7.12 Designing Interactive Interface Objects in Playgrounds 191
8. The User Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
8.1 Animating Details with Peek and Pop 195
8.2 Providing Dynamic 3D Touch Menus on Home Screen 202
8.3 Asking Your Users for App Store Reviews in Your App 205
8.4 Providing Vibrational Feedback to Users 206
8.5 Supporting Drag and Drop in Your Apps 210
8.6 Scaling Fonts in Order to Support Dynamic Types 219
8.7 Adjusting Labels While Supporting Dynamic Types 223
8.8 Extracting Named Colors from Asset Catalogs 229
8.9 Animating Views 230
8.10 Attaching Live Views to Playgrounds 234
8.11 Running Playgrounds as Interactive and Continuous Apps 237
8.12 Arranging Your Components Horizontally or Vertically 239
8.13 Customizing Stack Views for Different Screen Sizes 241
8.14 Creating Anchored Constraints in Code 245
8.15 Allowing Users to Enter Text in Response to Local and Remote
Notifications 250
8.16 Dealing with Stacked Views in Code 256
8.17 Showing Web Content in Safari View Controller 258
8.18 Laying Out Text-Based Content on Your Views 260
8.19 Improving Touch Rates for Smoother UI Interactions 261
8.20 Supporting Right-to-Left Languages 264
8.21 Associating Keyboard Shortcuts with View Controllers 269
8.22 Recording the Screen and Sharing the Video 270
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9. Document-Based Apps. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
9.1 Supporting File Browsing in Your App 277
9.2 Associating File Types with Your App 281
9.3 Creating New Documents 287
9.4 Saving Your Documents 297
9.5 Loading Existing Documents 312
9.6 Customizing Your Document Browser 315
10. Apple Watch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 319
10.1 Downloading Files onto the Apple Watch 320
10.2 Noticing Changes in Pairing State Between the iOS and Watch Apps 325
10.3 Transferring Small Pieces of Data to and from the Watch 328
10.4 Transferring Dictionaries in Queues to and from the Watch 338
10.5 Transferring Files to and from the Watch 342
10.6 Communicating Interactively Between iOS and watchOS 347
10.7 Setting Up the Apple Watch for Custom Complications 357
10.8 Constructing Small Complications with Text and Images 364
10.9 Displaying Time Offsets in Complications 374
10.10 Displaying Dates in Complications 381
10.11 Displaying Times in Complications 388
10.12 Displaying Time Intervals in Complications 393
10.13 Recording Audio in Your Watch App 400
10.14 Playing Local and Remote Audio and Video in Your Watch App 403
11. Contacts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 407
11.1 Creating Contacts 408
11.2 Searching for Contacts 414
11.3 Updating Contacts 418
11.4 Deleting Contacts 422
11.5 Formatting Contact Data 424
11.6 Picking Contacts with a Prebuilt System UI 428
11.7 Creating Contacts with a Prebuilt System UI 434
11.8 Displaying Contacts with a Prebuilt System UI 436
12. Extensions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 439
12.1 Creating Safari Content Blockers 439
12.2 Creating Shared Links for Safari 444
12.3 Maintaining Your App’s Indexed Content 447
13. Web and Search. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 451
13.1 Continuing a Spotlight Search Within Your App 451
13.2 Making Your App’s Content Searchable 455
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13.3 Making User Activities Searchable 460
13.4 Deleting Your App’s Searchable Content 463
14. Multitasking. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 465
14.1 Supporting Split Views 465
14.2 Adding Picture in Picture Playback Functionality 468
14.3 Handling Low Power Mode and Providing Alternatives 474
15. Maps and Location. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 477
15.1 Customizing the Map View with System Buttons 477
15.2 Displaying System Annotations on the Map 480
15.3 Clustering Annotations for a Clutter-Free Map 483
15.4 Displaying a Specific Location on the Map 490
15.5 Requesting the User’s Location a Single Time 493
15.6 Requesting the User’s Location in the Background 494
15.7 Customizing the Tint Color of Pins on the Map 496
15.8 Providing Detailed Pin Information with Custom Views 499
15.9 Displaying Traffic, Scale, and Compass Indicators on the Map 500
15.10 Providing an ETA for Transit Transport Type 502
15.11 Launching the iOS Maps App in Transit Mode 505
15.12 Showing Maps in Flyover Mode 506
16. UI Testing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 509
16.1 Preparing Your Project for UI Testing 509
16.2 Automating UI Test Scripts 512
16.3 Testing Text Fields, Buttons, and Labels 514
16.4 Finding UI Components 516
16.5 Long-Pressing on UI Elements 519
16.6 Typing Inside Text Fields 521
16.7 Swiping on UI Elements 523
16.8 Tapping UI Elements 524
17. Core Motion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 527
17.1 Querying Pace and Cadence Information 528
17.2 Recording and Reading Accelerometer Data 529
18. Security. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 531
18.1 Supporting Password Autofill with iCloud Keychain 531
18.2 Protecting Your Network Connections with ATS 534
18.3 Binding Keychain Items to Passcode and Touch ID 536
18.4 Opening URLs Safely 538
18.5 Authenticating the User with Touch ID and Timeout 539
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19. Multimedia. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 543
19.1 Reading Out Text with the Default Siri Alex Voice 543
19.2 Downloading and Preparing Remote Media for Playback 545
19.3 Enabling Spoken Audio Sessions 547
20. UI Dynamics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 549
20.1 Adding a Radial Gravity Field to Your UI 549
20.2 Creating a Linear Gravity Field on Your UI 554
20.3 Creating Turbulence Effects with Animations 557
20.4 Adding Animated Noise Effects to Your UI 559
20.5 Creating a Magnetic Effect Between UI Components 561
20.6 Designing a Velocity Field on Your UI 564
20.7 Handling Collisions Between Nonrectangular Views 566
21. iMessage Stickers and Apps. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 573
21.1 Setting Up a Sticker Pack Application 574
21.2 Adjusting Sticker Sizes 576
21.3 Building a Full-Fledged iMessage Application 577
21.4 Adding an iMessage App Extension to an Existing App 586
21.5 Utilizing an Expanded View in a Sticker Pack App 588
21.6 Appending Rich Information to Stickers 595
21.7 Creating Interactive Conversations with iMessage Apps 598
Index. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 609
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