iOS 8 App Extensions

A presentation originally delivered at Pragma Mark in Milan, Italy on October 4th, 2014,

Transcript

1. Extensions in
   iOS 8
   (like peanut butter and chocolate)
   

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2. Ben Scheirman
   @subdigital
   benscheirman.com
   

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3. ChaiOne
   Houston, TX
   @chaione
   

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4. NSScreencast
   

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5. Extensions!
   

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6. Your App + Other Apps
   

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7. Your App + 's Apps
   

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8. Extension Types Available
   

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9. Today Extension
   Add Widget to Notification
   Center
   

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10. Share Extension
    Share Content to Your App
    

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11. Action Extension
    Act Upon Content
    

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12. Keyboard
    Photo Editing
    Document Provider
    Not covered here :(
    

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13. Extension
    Architecture
    

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14. Isolated Process
    

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15. Independent Lifecycle
    

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16. Delivered with
    Applications
    

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19. Extensions are Just View
    Controllers
    

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20. The Ever-Important Info.plist
    

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21. NSExtension
    top level dictionary
    

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22. NSExtensionAttributes
    nested dictionary
    

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23. NSExtensionPrincipalClassName
    Provide a class to instantiate if not using
    storyboards.
    

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24. NSExtensionMainStoryboard
    Provide the name of your extension's storyboard.
    

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25. NSExtensionPointIdentifier
    Indicates the type of extension to the OS.
    

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26. What is an Activation Rule?
    

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27. Supported Activation Rules
    NSExtensionActivationSupportsAttachmentsWithMaxCount
    NSExtensionActivationSupportsAttachmentsWithMinCount
    NSExtensionActivationSupportsFileWithMaxCount
    NSExtensionActivationSupportsImageWithMaxCount
    NSExtensionActivationSupportsMovieWithMaxCount
    NSExtensionActivationSupportsText
    NSExtensionActivationSupportsWebURLWithMaxCount
    NSExtensionActivationSupportsWebPageWithMaxCount
    

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28. or a Predicate
    

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29. Default is TRUEPREDICATE
    

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30. Don't Ship with this!
    

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31. SUBQUERY (
    extensionItems,
    $extensionItem,
    SUBQUERY (
    $extensionItem.attachments,
    $attachment,
    ANY $attachment.registeredTypeIdentifiers UTI-CONFORMS-TO "com.adobe.pdf"
    ).@count == $extensionItem.attachments.@count
    ).@count == 1
    

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32. Info.plist
    Lots more options, read:
    https://developer.apple.com/library/prerelease/
    iOS/documentation/General/Reference/
    InfoPlistKeyReference/Articles/
    SystemExtensionKeys.html
    

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33. Sharing Code Between App
    and Extensions
    

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34. Easy way:
    just add a class to multiple targets!
    

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36. Though, you probably want to create a
    Framework
    

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39. Sharing Storyboards?
    

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40. Let's build a today extension
    

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41. Step 1: Add Extension
    Target
    

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43. Step 2: Design the Widget
    

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44. View Slide

45. Step 3: Share Common
    Code
    

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47. Step 4: Wire it up
    

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48. View Slide

49. Let's see
    it in action!
    

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51. How do I keep them in sync?
    

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52. Sharing Data between
    App and Extension
    

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53. Can Share:
    · NSUserDefaults
    · CoreData
    · Files
    · Background Transfer Sessions
    

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54. Create an App Group
    must start with "group."
    

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55. Create for containing app
    Create same group for extension
    

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57. Setup Shared NSUserDefaults
    var userDefaults: NSUserDefaults {
    get {
    return NSUserDefaults(suiteName: "group.com.nsscreencast.coffeetracker")
    }
    }
    

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58. Add to CoffeeTracker
    var numberOfCups: Int {
    get {
    return userDefaults.integerForKey("cups")
    }
    set {
    userDefaults.setInteger(newValue, forKey: "cups")
    updateDisplay()
    }
    }
    

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59. Handle Periodic Background Updates
    func widgetPerformUpdateWithCompletionHandler(completionHandler: (NCUpdateResult) -> ()) {
    coffeeTracker.updateDisplay()
    // If an error is encountered, use NCUpdateResult.Failed
    // If there's no update required, use NCUpdateResult.NoData
    // If there's an update, use NCUpdateResult.NewData
    completionHandler(NCUpdateResult.NewData)
    }
    

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60. Share Extensions
    

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61. · Share content to another app / service
    · Use System Sharing UI or Custom
    · Upload using shared background session
    

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62. Introducing... FoodBook
    

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63. Step 1:
    Add a framework for our
    shared code
    

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65. Useful for putting networking code or
    view controllers common to app and
    extension
    

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66. Step 2:
    Add a Share Extension
    Target
    

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68. Step 3:
    Update Info.plist
    

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71. Step 4:
    Edit View Controller
    

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72. (brace yourself)
    

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73. Import MobileCoreServices
    import MobileCoreServices
    

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74. Add a property to store the image being shared
    var image: UIImage?
    

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75. Get the Item Provider
    override func viewDidLoad() {
    var itemProvider: NSItemProvider?
    }
    

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76. Get the Item Provider
    override func viewDidLoad() {
    var itemProvider: NSItemProvider?
    if let items = extensionContext?.inputItems {
    }
    }
    

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77. Get the Item Provider
    override func viewDidLoad() {
    var itemProvider: NSItemProvider?
    if let items = extensionContext?.inputItems {
    if let item = items.first
    as? NSExtensionItem {
    }
    }
    }
    

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78. Get the Item Provider
    override func viewDidLoad() {
    var itemProvider: NSItemProvider?
    if let items = extensionContext?.inputItems {
    if let item = items.first
    as? NSExtensionItem {
    if let attachment = item.attachments?.first
    as? NSItemProvider {
    itemProvider = attachment
    }
    }
    }
    }
    

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79. Pull an image out of the item provider
    override func viewDidLoad() {
    // ...
    let imageType = kUTTypeImage as NSString
    if itemProvider?.hasItemConformingToTypeIdentifier(imageType) == true {
    }
    }
    

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80. Pull an image out of the item provider
    override func viewDidLoad() {
    // ...
    let imageType = kUTTypeImage as NSString
    if itemProvider?.hasItemConformingToTypeIdentifier(imageType) == true {
    itemProvider?.loadItemForTypeIdentifier(imageType, options: nil) {
    (item, error) in
    })
    }
    }
    

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81. Pull an image out of the item provider
    override func viewDidLoad() {
    // ...
    let imageType = kUTTypeImage as NSString
    if itemProvider?.hasItemConformingToTypeIdentifier(imageType) == true {
    itemProvider?.loadItemForTypeIdentifier(imageType, options: nil) {
    (item, error) in
    if error == nil {
    let url = item as NSURL
    let imageData = NSData(contentsOfURL: url)
    self.image = UIImage(data: imageData)
    } else {
    println("ERROR: \(error)")
    }
    })
    }
    }
    

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82. Step 5: Perform the upload
    

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83. override func didSelectPost() {
    FoodBookApiClient.upload(image) {
    self.extensionContext!.completeRequestReturningItems([],
    completionHandler: nil)
    }
    }
    

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84. Let's see
    it in action!
    

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86. Can also bring your own
    view controller
    

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87. Action Extensions
    

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88. Act upon content user is looking at
    

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90. Access to Entire DOM
    

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91. Supply JavaScript that formats the input and
    handles the output
    

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93. Action.js
    var Action = function() {};
    Action.prototype = {
    run: function(arguments) {
    },
    finalize: function(arguments) {
    }
    };
    var ExtensionPreprocessingJS = new Action
    

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94. run: function(arguments) {
    arguments.completionFunction({
    "host": window.location.host,
    "path": window.location.pathname
    })
    },
    

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95. App will receive
    PropertyList Item Type
    

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96. func beginRequestWithExtensionContext(context: NSExtensionContext) {
    self.extensionContext = context
    var itemProvider: NSItemProvider?
    if let item = context.inputItems.first as? NSExtensionItem {
    if let attachment = item.attachments?.first as? NSItemProvider {
    itemProvider = attachment
    }
    }
    let itemType = String(kUTTypePropertyList)
    if itemProvider?.hasItemConformingToTypeIdentifier(itemType) == true {
    itemProvider?.loadItemForTypeIdentifier(itemType, options: nil) {
    item, error in
    let dictionary = item as NSDictionary
    NSOperationQueue.mainQueue().addOperationWithBlock {
    let preprocessingResults = dictionary[NSExtensionJavaScriptPreprocessingResultsKey]
    as [NSObject:AnyObject]
    self.itemLoadCompletedWithPreprocessingResults(preprocessingResults)
    }
    }
    } else {
    self.doneWithResults(nil)
    }
    }
    

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97. let dictionary = item as NSDictionary
    NSOperationQueue.mainQueue().addOperationWithBlock {
    let results = dictionary[NSExtensionJavaScriptPreprocessingResultsKey]
    as NSDictionary
    self.itemLoadCompletedWithPreprocessingResults(results)
    

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98. func itemLoadCompletedWithPreprocessingResults(results: NSDictionary) {
    let host = results["host"] as String
    let path = results["path"] as String
    let newURL = "http://cat.\(host).meowbify.com\(path)"
    doneWithResults(["newURL": newURL])
    }
    

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99. Prepare the results to go back to
    the JavaScript object
    

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100. func doneWithResults(results: NSDictionary?) {
     if let finalizeResults = results {
     var resultsDictionary = [NSExtensionJavaScriptFinalizeArgumentKey: finalizeResults]
     let itemType = kUTTypePropertyList as NSString
     var resultsProvider = NSItemProvider(item: resultsDictionary, typeIdentifier: itemType)
     var resultsItem = NSExtensionItem()
     resultsItem.attachments = [resultsProvider]
     extensionContext?.completeRequestReturningItems([resultsItem], completionHandler: nil)
     } else {
     extensionContext?.completeRequestReturningItems(nil, completionHandler: nil)
     }
     extensionContext = nil
     }
     

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101. Handle the results in JavaScript
     

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102. finalize: function(arguments) {
     window.location = arguments["newURL"];
     }
     

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103. OMG, can we run it yet?
     

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105. Questions?
     

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106. Thank you!
     Slide links: http://speakerdeck.com/subdigital/ios8-app-extension
     Code links: https://github.com/subdigital/pragma-mark-2014
     Ben Scheirman
     ben@scheirman.com
     @subdigital
     @nsscreencast
     

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