NSSpain 2016: Building Fabric.app in Swift

Overview of some of the technical decisions made during the development of the Fabric app for iOS.

Transcript

1. Building the Fabric iOS App
   @Javi
   1 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
   

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2. Outline
   → Fabric
   → GraphQL
   → Dependency Injection
   → Error Reporting
   → Fastlane
   2 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
   

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3. What's Fabric?
   3 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
   

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4. Fabric
   4 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
   

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5. Fabric
   5 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
   

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6. GraphQL1
   1 http://graphql.org/
   6 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
   

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7. GraphQL - Queries
   → GET /users/
   7 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
   

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8. GraphQL - Queries
   → GET /users/
   → GET /users//friends
   8 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
   

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9. GraphQL - Queries
   9 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
   

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10. GraphQL - Queries
    {
    user(id: 4802170) {
    name
    profilePicture(size: 50) {
    uri
    width
    }
    friends(first: 5) {
    id
    name
    }
    }
    }
    10 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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11. GraphQL - Queries
    {
    "data": {
    "user": {
    "id": "4802170",
    "name": "Javi",
    "profilePicture": {
    "uri": "http://bit.ly/1E8lYDq",
    "width": 50
    },
    "friends": [
    {
    "id": "305249",
    "name": "Jony Ive"
    },
    {
    "id": "3108935",
    "name": "Elon Musk"
    }
    ]
    }
    }
    }
    11 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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12. GraphQL - Features
    → Hierarchical, human-readable query language
    → Strongly-typed
    → Version free
    12 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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13. GraphQL - GraphiQL
    13 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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14. Dependency Injection
    14 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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15. Dependency injection
    Software design pattern that implements inversion
    of control for resolving dependencies. An injection is
    the passing of a dependency to a dependent object
    that would use it.
    — https://en.wikipedia.org/wiki/
    Dependency_injection
    15 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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16. Dependencies
    → View Controller => Data Provider
    → Data Provider => API Client
    → Persistence Manager => Database Client
    16 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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17. Dependency Resolution
    → Self-instantiation
    → Global access
    → Injection via setters
    → Injection via constructor
    17 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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18. Dependency Resolution - Self-Instantiation
    class ViewController {
    private let dataProvider: DataProvider
    init() {
    self.dataProvider = DataProvider()
    }
    }
    18 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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19. Dependency Resolution - Global Access
    class ViewController {
    private let dataProvider: DataProvider
    init() {
    self.dataProvider = DataProvider.shared
    }
    }
    19 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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20. Dependency Resolution - Injection via Setters
    class ViewController {
    var dataProvider: DataProvider!
    init() {
    }
    }
    20 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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21. Dependency Resolution - Injection via Constructor
    class ViewController {
    private let dataProvider: DataProvider
    init(dataProvider: DataProvider) {
    self.dataProvider = dataProvider
    }
    }
    21 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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22. Easy vs Simple
    22 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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23. Easy - Hard
    Simple - Complex
    23 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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24. Dependency injection
    Implicit vs explicit
    24 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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25. Dependency injection - UIStoryboard
    class UIStoryboard {
    func instantiateViewController(withIdentifier identifier: String) -> UIViewController
    }
    25 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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26. Dependency injection - UIStoryboard
    let sb = UIStoryboard...
    let vc = sb.instantiateViewController(withIdentifier: "ID") as! ApplicationOverviewVC
    vc.userSession = ...
    vc.applicationID = ...
    26 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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27. Dependency injection - UIStoryboard
    final class ApplicationOverviewVC {
    // I hope you like "!"s...
    var userSession: UserSession!
    var applicationID: String!
    func viewDidLoad() {
    super.viewDidLoad()
    self.userSession.foo()
    // Or...
    if let userSession = self.userSession {
    userSession.foo()
    } else { /* Can't do anything useful here... */ }
    }
    }
    27 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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28. 28 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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29. Dependency injection in the Fabric app
    final class ApplicationListViewController: UIViewController {
    init(viewModel: ApplicationListViewModel)
    }
    final class ApplicationListViewModel {
    init(fabricAPI: AuthenticatedFabricAPI)
    }
    public final class AuthenticatedFabricAPI {
    public init(session: Session)
    }
    public struct Session {
    let accessToken: String
    }
    29 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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30. DataLoadState
    final class ApplicationListViewModel {
    var applications: [Application]?
    }
    30 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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31. DataLoadState
    enum DataLoadState {
    case loading
    case failed
    case loaded(T)
    }
    final class ApplicationListViewModel {
    var applications: DataLoadState = .loading
    }
    31 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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32. Error Reporting
    32 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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33. Error Reporting
    class Crashlytics {
    public func record(_ error: NSError, withAdditionalUserInfo: [AnyHashable : Any]?)
    }
    33 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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34. Error Reporting
    34 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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35. Error Reporting
    public protocol ReportableError: Swift.Error {
    var info: [String : Any] { get }
    var underlyingErrors: [ReportableError] { get }
    }
    35 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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36. Error Reporting
    private enum URLHandlerError: ReportableError {
    case unknownURL(URL)
    case malformedURLMissingParameter
    /// This is useful because the `NSError` conversion will only give us a "code" integer.
    private var name: String {
    switch self {
    case .unknownURL: return "UnknownURL"
    case .malformedURLMissingParameter: return "MalformedURLMissingParameter"
    }
    }
    var info: [String : Any] {
    var info: [String : Any] = ["name": self.name]
    switch self {
    case let .unknownURL(url): info["url"] = url.path ?? ""
    case .malformedURLMissingParameter: ()
    }
    return info
    }
    }
    36 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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37. Error Reporting
    extension ReportableError {
    var errorCode: Int {
    return (self as Error).code
    }
    var errorDomain: String {
    return (self as Error).domain
    }
    var asNSError: NSError {
    return NSError(
    domain: self.errorDomain,
    code: self.errorCode,
    userInfo: self.info
    )
    }
    }
    37 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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38. Error Reporting
    var allErrors: [ReportableError] {
    return [
    [self],
    self.underlyingErrors.flatMap { $0.allErrors } // Recur
    ]
    .flatMap { $0 }
    }
    38 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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39. Error Reporting
    public final class ErrorReporting {
    // We get file and function names for free
    internal func report(
    error: ReportableError,
    filePath: StaticString = #file,
    functionName: StaticString = #function,
    lineNumber: Int = #line
    ) {
    error.allErrors.forEach {
    var userInfo = $0.info
    userInfo["file"] = "\((filePath as NSString).lastPathComponent):\(lineNumber)"
    userInfo["function"] = functionName
    Crashlytics.sharedInstance().recordError($0.asNSError, withAdditionalUserInfo: userInfo)
    }
    }
    }
    39 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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40. 40 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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41. Fastlane
    → Code signing
    → Deployment
    41 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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42. Fastlane - Code Signing
    42 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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43. Fastlane - Code Signing
    https://codesigning.guide/
    43 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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44. Fastlane -
    44 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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45. Fastlane - Deployment
    45 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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46. Fastlane - Deployment
    lane :appstore do
    snapshot # Generate screenshots for the App Store
    match # Ensure code signing is set-up
    gym # Build your app
    deliver # Upload the screenshots and the binary to iTunes
    slack # Let your team-mates know the new version is live
    end
    46 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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47. Fastlane - Deployment
    lane :appstore do
    snapshot # Generate screenshots for the App Store
    match # Ensure code signing is set-up
    gym # Build your app
    deliver # Upload the screenshots and the binary to iTunes
    slack # Let your team-mates know the new version is live
    end
    $ fastlane appstore
    47 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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48. Fastlane - Deployment
    lane :appstore do |options|
    ensure_git_branch(branch: "(master|release\\S+)")
    ensure_git_status_clean
    ensure_xcode_version(version: "8.0")
    increment_version_number(version_number: options[:version_number])
    build_number = increment_build_number
    complete_version_number = "#{version_number} (#{build_number})"
    commit_version_bump(message: "Version bump to #{complete_version_number}")
    set_github_release(repository_name: "...", name: complete_version_number)
    ...
    end
    $ fastlane appstore version_number:1.6.0
    48 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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49. Fastlane.tools
    49 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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50. Questions?
    @Javi / javi@twitter.com
    50 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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51. Thanks !
    51 — "Building the Fabric iOS App" - @Javi. NSSpain 2016
    

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