Merge pull request #10 from ashfurrow/alertaction

Added UIAlertAction extension.

Author: fpillet

Action.podspec

@@ -18,12 +18,13 @@ Pod::Spec.new do |s|
   s.tvos.deployment_target = '9.0'
 
   s.source       = { :git => "https://github.com/ashfurrow/Action.git", :tag => s.version }
-  s.source_files  = "*.swift"
+  s.source_files  = "*.{swift}"
+
   s.frameworks  = "Foundation"
   s.dependency "RxSwift", '~> 2.0.0-beta'
   s.dependency "RxCocoa", '~> 2.0.0-beta'
 
-  s.watchos.exclude_files = "UIButton+Rx.swift", "UIBarButtonItem+Action.swift"
-  s.osx.exclude_files = "UIButton+Rx.swift", "UIBarButtonItem+Action.swift"
-  s.tvos.exclude_files = "UIBarButtonItem+Action.swift"
+  s.watchos.exclude_files = "UIButton+Rx.swift", "UIBarButtonItem+Action.swift", "AlertAction.swift"
+  s.osx.exclude_files = "UIButton+Rx.swift", "UIBarButtonItem+Action.swift", "AlertAction.swift"
+  s.tvos.exclude_files = "UIBarButtonItem+Action.swift", "AlertAction.swift"
 end

AlertAction.swift

@@ -0,0 +1,66 @@
+import UIKit
+import RxSwift
+import RxCocoa
+
+public extension UIAlertAction {
+
+    public static func Action(title: String?, style: UIAlertActionStyle) -> UIAlertAction {
+        return UIAlertAction(title: title, style: style, handler: { action in
+            action.rx_action?.execute()
+        })
+    }
+
+    /// Binds enabled state of action to button, and subscribes to rx_tap to execute action.
+    /// These subscriptions are managed in a private, inaccessible dispose bag. To cancel
+    /// them, set the rx_action to nil or another action.
+    public var rx_action: CocoaAction? {
+        get {
+            var action: CocoaAction?
+            doLocked {
+                action = objc_getAssociatedObject(self, &AssociatedKeys.Action) as? Action
+            }
+            return action
+        }
+
+        set {
+            doLocked {
+                // Store new value.
+                objc_setAssociatedObject(self, &AssociatedKeys.Action, newValue, .OBJC_ASSOCIATION_RETAIN_NONATOMIC)
+
+                // This effectively disposes of any existing subscriptions.
+                self.resetActionDisposeBag()
+
+                // Set up new bindings, if applicable.
+                if let action = newValue {
+                    action
+                        .enabled
+                        .bindTo(self.rx_enabled)
+                        .addDisposableTo(self.actionDisposeBag)
+                }
+            }
+        }
+    }
+}
+
+extension UIAlertAction {
+    var rx_enabled: AnyObserver<Bool> {
+        return AnyObserver { [weak self] event in
+            MainScheduler.ensureExecutingOnScheduler()
+
+            switch event {
+            case .Next(let value):
+                self?.enabled = value
+            case .Error(let error):
+                let error = "Binding error to UI: \(error)"
+                #if DEBUG
+                    rxFatalError(error)
+                #else
+                    print(error)
+                #endif
+                break
+            case .Completed:
+                break
+            }
+        }
+    }
+}

Demo/Demo.xcodeproj/project.pbxproj

@@ -35,29 +35,29 @@
                         <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                         <subviews>
                             <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="roundedRect" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="SZL-3G-VZh">
-                                <rect key="frame" x="277" y="31" width="46" height="30"/>
+                                <rect key="frame" x="264" y="31" width="73" height="30"/>
                                 <animations/>
-                                <state key="normal" title="Button"/>
+                                <state key="normal" title="Show alert"/>
                             </button>
-                            <activityIndicatorView hidden="YES" opaque="NO" contentMode="scaleToFill" horizontalHuggingPriority="750" verticalHuggingPriority="750" hidesWhenStopped="YES" style="gray" translatesAutoresizingMaskIntoConstraints="NO" id="OrY-7C-i77">
-                                <rect key="frame" x="290" y="258" width="20" height="20"/>
-                            </activityIndicatorView>
                             <label hidden="YES" opaque="NO" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="251" verticalHuggingPriority="251" text="Doing some work" textAlignment="natural" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" translatesAutoresizingMaskIntoConstraints="NO" id="ulN-2s-mAd">
-                                <rect key="frame" x="234" y="229" width="133" height="21"/>
+                                <rect key="frame" x="234" y="467" width="133" height="21"/>
                                 <fontDescription key="fontDescription" type="system" pointSize="17"/>
                                 <color key="textColor" cocoaTouchSystemColor="darkTextColor"/>
                                 <nil key="highlightedColor"/>
                             </label>
+                            <activityIndicatorView hidden="YES" opaque="NO" contentMode="scaleToFill" horizontalHuggingPriority="750" verticalHuggingPriority="750" hidesWhenStopped="YES" style="gray" translatesAutoresizingMaskIntoConstraints="NO" id="OrY-7C-i77">
+                                <rect key="frame" x="290" y="496" width="20" height="20"/>
+                            </activityIndicatorView>
                         </subviews>
                         <animations/>
                         <color key="backgroundColor" white="1" alpha="1" colorSpace="custom" customColorSpace="calibratedWhite"/>
                         <constraints>
                             <constraint firstItem="OrY-7C-i77" firstAttribute="centerX" secondItem="8bC-Xf-vdC" secondAttribute="centerX" id="Dyl-A6-bud"/>
-                            <constraint firstItem="OrY-7C-i77" firstAttribute="centerY" secondItem="8bC-Xf-vdC" secondAttribute="centerY" id="KWX-Rs-PVL"/>
                             <constraint firstItem="SZL-3G-VZh" firstAttribute="top" secondItem="y3c-jy-aDJ" secondAttribute="bottom" constant="31" id="Np0-fa-c3f"/>
                             <constraint firstItem="ulN-2s-mAd" firstAttribute="centerX" secondItem="8bC-Xf-vdC" secondAttribute="centerX" id="a5T-qt-gDR"/>
                             <constraint firstItem="OrY-7C-i77" firstAttribute="top" secondItem="ulN-2s-mAd" secondAttribute="bottom" constant="8" id="eqf-Tp-OJd"/>
                             <constraint firstItem="SZL-3G-VZh" firstAttribute="centerX" secondItem="8bC-Xf-vdC" secondAttribute="centerX" id="hb0-j9-0rK"/>
+                            <constraint firstItem="wfy-db-euE" firstAttribute="top" secondItem="OrY-7C-i77" secondAttribute="bottom" constant="20" id="jhU-Jj-aCX"/>
                         </constraints>
                     </view>
                     <extendedEdge key="edgesForExtendedLayout"/>

Demo/Demo/Base.lproj/Main.storyboard

@@ -22,12 +22,23 @@ class ViewController: UIViewController {
         super.viewDidLoad()
 
         // Demo: add an action to a button in the view
-        let action = CocoaAction { _ in
-            return create { observer -> Disposable in
-                // Do whatever work here.
-                print("Doing work for button at \(NSDate())")
-                observer.onCompleted()
-                return NopDisposable.instance
+        let action = CocoaAction {
+			print("Button was pressed, showing an alert and keeping the activity indicator spinning while alert is displayed")
+            return create {
+				[weak self] observer -> Disposable in
+
+				// Demo: show an alert and complete the view's button action once the alert's OK button is pressed
+				let alertController = UIAlertController(title: "Hello world", message: "This alert was triggered by a button action", preferredStyle: .Alert)
+				let ok = UIAlertAction.Action("OK", style: .Default)
+				ok.rx_action = CocoaAction {
+					print("Alert's OK button was pressed")
+					observer.onCompleted()
+					return empty()
+				}
+				alertController.addAction(ok)
+				self!.presentViewController(alertController, animated: true, completion: nil)
+
+				return NopDisposable.instance
             }
         }
         button.rx_action = action
@@ -38,7 +49,7 @@ class ViewController: UIViewController {
             return empty().delaySubscription(2, MainScheduler.sharedInstance)
         }
 
-        // Demo: obseve the output of both actions, spin an activity indicator
+        // Demo: observe the output of both actions, spin an activity indicator
         // while performing the work
         combineLatest(
             button.rx_action!.executing,

Demo/Demo/ViewController.swift

@@ -0,0 +1,75 @@
+import Quick
+import Nimble
+import RxSwift
+import RxBlocking
+import Action
+
+class AlertActionTests: QuickSpec {
+    override func spec() {
+        it("is nil by default") {
+            let subject = UIAlertAction.Action("Hi", style: .Default)
+            expect(subject.rx_action).to( beNil() )
+        }
+
+        it("respects setter") {
+            let subject = UIAlertAction.Action("Hi", style: .Default)
+
+            let action = emptyAction()
+
+            subject.rx_action = action
+
+            expect(subject.rx_action) === action
+        }
+
+        it("disables the button while executing") {
+            let subject = UIAlertAction.Action("Hi", style: .Default)
+
+            var observer: AnyObserver<Void>!
+            let action = CocoaAction(workFactory: { _ in
+                return create { (obsv) -> Disposable in
+                    observer = obsv
+                    return NopDisposable.instance
+                }
+            })
+
+            subject.rx_action = action
+
+            action.execute()
+            expect(subject.enabled).toEventually( beFalse() )
+
+            observer.onCompleted()
+            expect(subject.enabled).toEventually( beTrue() )
+        }
+
+        it("disables the button if the Action is disabled") {
+            let subject = UIAlertAction.Action("Hi", style: .Default)
+
+            subject.rx_action = emptyAction(just(false))
+
+            expect(subject.enabled) == false
+        }
+        
+        it("disposes of old action subscriptions when re-set") {
+            let subject = UIAlertAction.Action("Hi", style: .Default)
+            
+            var disposed = false
+            autoreleasepool {
+                let disposeBag = DisposeBag()
+                
+                let action = emptyAction()
+                subject.rx_action = action
+                
+                action
+                    .elements
+                    .subscribe(onNext: nil, onError: nil, onCompleted: nil, onDisposed: {
+                        disposed = true
+                    })
+                    .addDisposableTo(disposeBag)
+            }
+            
+            subject.rx_action = nil
+            
+            expect(disposed) == true
+        }
+    }
+}

Demo/DemoTests/AlertActionTests.swift

@@ -1,5 +1,5 @@
 PODS:
-  - Action (0.1.0):
+  - Action (0.2.0):
     - RxCocoa (~> 2.0.0-beta)
     - RxSwift (~> 2.0.0-beta)
   - Nimble (3.0.0)
@@ -23,7 +23,7 @@ EXTERNAL SOURCES:
     :path: "../"
 
 SPEC CHECKSUMS:
-  Action: dbcbc4c9255e54f801c14554a58d1ed6b5c1d47e
+  Action: 836da3ae9615435467a3d1cddd384f4ea6036ba2
   Nimble: 4c353d43735b38b545cbb4cb91504588eb5de926
   Quick: 563d0f6ec5f72e394645adb377708639b7dd38ab
   RxBlocking: 331f8bdedf77198f8ff1a37f09c492f1f4f631e5

Demo/Podfile.lock

@@ -56,6 +56,12 @@ button.rx_action = action
 
 Now when the button is pressed, the action is executed. The button's `enabled` state is bound to the action's `enabled` property. That means you can feed your form-validation logic into the action as a signal, and your button's enabled state is handled for you. Also, the user can't press the button again before the action is done executing, since it only handles one thing at a time. Cool.
 
+There's also a really cool extension on `UIAlertAction`, used by [`UIAlertController`](http://ashfurrow.com/blog/uialertviewcontroller-example/). One catch: because of the limitations of that class, you can't instantiate it with the normal initializer. Instead, call this class method:
+
+```swift
+let action = UIAlertAction.Action("Hi", style: .Default)
+```
+
 **NOTE**: Due to a temporary issue with RxSwift, there's a [slight issue](https://github.com/ashfurrow/Action/issues/3) that shouldn't affect you, but might. Who knows!
 
 Installing