Building Fabric.app with ReactiveCocoa

Overview of how the Fabric App was built by taking advantage of some of ReactiveCocoa's features.

Transcript

1. Building Fabric.app with Reac5veCocoa
   "Building Fabric.app with Reac6veCocoa" - Javier Soto. RACDC2016 - April 2016 1
   

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2. Intro
   @Javi
   "Building Fabric.app with Reac6veCocoa" - Javier Soto. RACDC2016 - April 2016 2
   

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3. Outline
   • Intro
   • History
   • Contribu.ng to Reac.veCocoa
   • Fabric App Architecture
   • RAC examples from Fabric App
   "Building Fabric.app with Reac6veCocoa" - Javier Soto. RACDC2016 - April 2016 3
   

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4. Intro: What is Fabric.app?
   "Building Fabric.app with Reac6veCocoa" - Javier Soto. RACDC2016 - April 2016 4
   

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5. What is Fabric.app?
   "Building Fabric.app with Reac6veCocoa" - Javier Soto. RACDC2016 - April 2016 5
   

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6. History
   h"ps:/
   /github.com/blog/1107-reac8vecocoa-for-a-be"er-world
   "Building Fabric.app with Reac6veCocoa" - Javier Soto. RACDC2016 - April 2016 6
   

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7. History
   • Reac&veCocoa 1: May 2012 (Objec&ve-C)
   • Reac&veCocoa 2: September 2013 (Objec&ve-C)
   • Reac&veCocoa 3: September 2015 (Swi@ 1)
   • Reac&veCocoa 4: January 2016 (Swi@ 2)
   "Building Fabric.app with Reac6veCocoa" - Javier Soto. RACDC2016 - April 2016 7
   

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8. "Building Fabric.app with Reac6veCocoa" - Javier Soto. RACDC2016 - April 2016 8
   

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9. Contribu)ng to Reac)veCocoa
   "Building Fabric.app with Reac6veCocoa" - Javier Soto. RACDC2016 - April 2016 9
   

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10. Contribu)ng to Reac)veCocoa: Coding
    • Refactoring
    • New tests
    • Proposing new operators
    • Compa5bility with new Swi; versions
    "Building Fabric.app with Reac6veCocoa" - Javier Soto. RACDC2016 - April 2016 10
    

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11. Contribu)ng to Reac)veCocoa: Other ways!
    • Replying to issues
    • Wri1ng / improving docs
    • Helping other users
    • Evangelizing
    "Building Fabric.app with Reac6veCocoa" - Javier Soto. RACDC2016 - April 2016 11
    

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12. Fabric App Architecture
    "Building Fabric.app with Reac6veCocoa" - Javier Soto. RACDC2016 - April 2016 12
    

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13. Fabric App Architecture
    • FabricAPI.framework:
    • Networking
    • Models
    • Fabric App:
    • View Controllers
    • View Models
    "Building Fabric.app with Reac6veCocoa" - Javier Soto. RACDC2016 - April 2016 13
    

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14. Examples of Usage of Reac0veCocoa in the
    Fabric App
    "Building Fabric.app with Reac6veCocoa" - Javier Soto. RACDC2016 - April 2016 14
    

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15. Examples - Networking
    final class AuthenticatedFabricAPI {
    func applications() -> SignalProducer<[Application], FabricAPIError> {
    return apiNetworking.requestJSONProducer(
    URL: APIURL(path: "api/v3/projects"),
    method: .GET
    )
    .attemptMap(Application.decodeObjectsInJSON)
    .observeOn(UIScheduler())
    }
    }
    "Building Fabric.app with Reac6veCocoa" - Javier Soto. RACDC2016 - April 2016 15
    

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16. DataLoadState
    final class MyViewModel {
    var data: MyEntity?
    }
    "Building Fabric.app with Reac6veCocoa" - Javier Soto. RACDC2016 - April 2016 16
    

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17. DataLoadState
    enum DataLoadState {
    case Loading
    case Failed
    case Loaded(DataType)
    }
    "Building Fabric.app with Reac6veCocoa" - Javier Soto. RACDC2016 - April 2016 17
    

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18. DataLoadState
    enum DataLoadState {
    case Loading
    case Failed
    case Loaded(DataType)
    }
    extension SignalProducerType {
    func materializeToLoadState() -> SignalProducer, NoError> {
    let producer = self
    .map(DataLoadState.Loaded)
    .startWithValue(DataLoadState.Loading)
    return producer.ignoreErrors(replacementValue: DataLoadState.Failed)
    }
    }
    "Building Fabric.app with Reac6veCocoa" - Javier Soto. RACDC2016 - April 2016 18
    

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19. extension SignalProducerType where Value: DataLoadState {
    func ignoreLoadingAndErrorsAfterSuccess() -> SignalProducer, Error> {
    var hasSuccededOnce = false
    return self.filter { value in
    defer {
    if value.success {
    hasSuccededOnce = true
    }
    }
    return !hasSuccededOnce || value.success
    }
    }
    "Building Fabric.app with Reac6veCocoa" - Javier Soto. RACDC2016 - April 2016 19
    

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20. Examples - View Models
    typealias ApplicationLoadState = DataLoadState<[Application]>
    final class ApplicationListViewModel {
    let applications: AnyProperty
    private let applicationsMutableProperty = MutableProperty(ApplicationLoadState.loading())
    init(fabricAPI: AuthenticatedFabricAPI) {
    self.applications = AnyProperty(self.applicationsMutableProperty)
    self.applicationsMutableProperty <~ fabricAPI.applications().materializeToLoadState()
    }
    }
    "Building Fabric.app with Reac6veCocoa" - Javier Soto. RACDC2016 - April 2016 20
    

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21. Examples - Consuming Data From a View Model
    self.viewModel.applications.producer.startWithNext { applicationsLoadState in
    switch applicationsLoadState {
    case .Loading:
    label.text = "Loading..."
    case .Failed:
    label.text = "Error loading applications!"
    case .Loaded(let applications):
    reloadTableView(applications: applications)
    }
    }
    "Building Fabric.app with Reac6veCocoa" - Javier Soto. RACDC2016 - April 2016 21
    

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22. Reac%veCocoa Extensions
    "Building Fabric.app with Reac6veCocoa" - Javier Soto. RACDC2016 - April 2016 22
    

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23. extension SignalProducerType {
    func startWithValue(value: Value) -> SignalProducer {
    return SignalProducer(value: value).concat(self.producer)
    }
    }
    "Building Fabric.app with Reac6veCocoa" - Javier Soto. RACDC2016 - April 2016 23
    

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24. Reac%veCocoa Extensions
    extension SignalProducerType {
    func startWithNil() -> SignalProducer {
    return self
    .map(Optional.init)
    .startWithValue(nil)
    }
    "Building Fabric.app with Reac6veCocoa" - Javier Soto. RACDC2016 - April 2016 24
    

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25. Reac%veCocoa Extensions
    extension SignalProducerType {
    func ignoreErrors(
    replacementValue replacementValue: Self.Value? = nil
    ) -> SignalProducer {
    return self.flatMapError { _ in
    return replacementValue.map(SignalProducer.init) ?? .empty
    }
    }
    "Building Fabric.app with Reac6veCocoa" - Javier Soto. RACDC2016 - April 2016 25
    

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26. Reac%veCocoa Extensions
    extension SignalProducerType {
    func failRandomly(withError error: Self.Error) -> SignalProducer {
    return self.attemptMap { value in
    let shouldFail = arc4random() % 3 == 0
    return shouldFail ? Result(error: error) : Result(value: value)
    }
    }
    "Building Fabric.app with Reac6veCocoa" - Javier Soto. RACDC2016 - April 2016 26
    

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27. Reac%veCocoa Extensions
    extension NSProcessInfo {
    var lowPowerModelEnabledProducer: SignalProducer {
    return NSNotificationCenter.defaultCenter()
    .rac_notifications(NSProcessInfoPowerStateDidChangeNotification, object: nil)
    .map { _ in return () }
    .startWithValue(())
    .map { [unowned self] _ in
    return self.lowPowerModeEnabled
    }
    .skipRepeats(==)
    }
    }
    "Building Fabric.app with Reac6veCocoa" - Javier Soto. RACDC2016 - April 2016 27
    

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28. Reac%veCocoa Extensions
    let shouldReload = combineLatest(
    viewIsOnScreen,
    NSProcessInfo.processInfo().lowPowerModelEnabledProducer.map { !$0 }
    ).map { $0 && $1 }
    let reloadPeriodically = shouldReload
    .flatMap(.Latest) { [unowned self] shouldReload in
    return shouldReload ?
    timer(30, onScheduler: scheduler).map { _ in () }
    : .empty
    }
    let request = reloadPeriodically.flatMap(.Latest) { someAPIRequest }
    "Building Fabric.app with Reac6veCocoa" - Javier Soto. RACDC2016 - April 2016 28
    

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29. Reac%veCocoa Extensions
    extension SignalProducerType {
    func continueWhenApplicationIsBackgrounded(
    taskName taskName: String,
    timeoutError: Self.Error
    ) -> SignalProducer {
    }
    "Building Fabric.app with Reac6veCocoa" - Javier Soto. RACDC2016 - April 2016 29
    

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30. Reac%veCocoa Extensions
    extension SignalProducerType {
    func repeatWith(
    producer: SignalProducer<(), NoError>,
    throttleWithInterval: NSTimeInterval,
    onScheduler scheduler: DateSchedulerType
    ) -> SignalProducer {
    return SignalProducer(value: ()).concat(producer)
    .throttle(throttleWithInterval, onScheduler: scheduler)
    .promoteErrors(Error)
    .flatMap(.Concat) { _ in
    return self.producer
    }
    }
    }
    "Building Fabric.app with Reac6veCocoa" - Javier Soto. RACDC2016 - April 2016 30
    

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31. Reac%veCocoa Extensions
    self.api.request(parameterFoo: bar)
    .repeatWith(
    viewWillAppearProducer,
    throttleWithInterval: 60,
    onScheduler: QueueScheduler.mainQueueScheduler
    )
    "Building Fabric.app with Reac6veCocoa" - Javier Soto. RACDC2016 - April 2016 31
    

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32. Conclusion
    "Building Fabric.app with Reac6veCocoa" - Javier Soto. RACDC2016 - April 2016 32
    

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33. Ques%ons?
    "Building Fabric.app with Reac6veCocoa" - Javier Soto. RACDC2016 - April 2016 33
    

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34. Thank you! <3 !
    See you next year!
    "Building Fabric.app with Reac6veCocoa" - Javier Soto. RACDC2016 - April 2016 34
    

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