Add KVO Publisher

ReactiveKit.podspec

@@ -1,12 +1,12 @@
 Pod::Spec.new do |s|
   s.name             = "ReactiveKit"
-  s.version          = "3.16.1"
+  s.version          = "3.16.2"
   s.summary          = "A Swift Reactive Programming Framework"
   s.description      = "ReactiveKit is a Swift framework for reactive and functional reactive programming."
   s.homepage         = "https://github.com/DeclarativeHub/ReactiveKit"
   s.license          = 'MIT'
   s.author           = { "Srdan Rasic" => "[email protected]" }
-  s.source           = { :git => "https://github.com/DeclarativeHub/ReactiveKit.git", :tag => "v3.16.1" }
+  s.source           = { :git => "https://github.com/DeclarativeHub/ReactiveKit.git", :tag => "v3.16.2" }
 
   s.ios.deployment_target       = '8.0'
   s.osx.deployment_target       = '10.11'

ReactiveKit.xcodeproj/project.pbxproj

@@ -1041,7 +1041,7 @@
 				GCC_WARN_UNUSED_VARIABLE = YES;
 				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
 				MACOSX_DEPLOYMENT_TARGET = 10.10;
-				MARKETING_VERSION = 3.16.1;
+				MARKETING_VERSION = 3.16.2;
 				MTL_ENABLE_DEBUG_INFO = YES;
 				ONLY_ACTIVE_ARCH = YES;
 				SDKROOT = iphoneos;
@@ -1096,7 +1096,7 @@
 				GCC_WARN_UNUSED_VARIABLE = YES;
 				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
 				MACOSX_DEPLOYMENT_TARGET = 10.10;
-				MARKETING_VERSION = 3.16.1;
+				MARKETING_VERSION = 3.16.2;
 				MTL_ENABLE_DEBUG_INFO = NO;
 				SDKROOT = iphoneos;
 				SWIFT_VERSION = 4.0;

Sources/Reactive.swift

@@ -76,6 +76,29 @@ extension ReactiveExtensions where Base: NSObject {
     public var bag: DisposeBag {
         return base.bag
     }
+
+    /// Create a Signal that establishes a key-value observation of the given key path when observed.
+    ///
+    /// For example:
+    ///
+    ///     let player = AVPlayer()
+    ///     player.reactive.publisher(for: \.status).sink { print("Playback status: \($0)") }
+    ///
+    public func publisher<Value>(for keyPath: KeyPath<Base, Value>, options: NSKeyValueObservingOptions = [.initial, .new]) -> Signal<Value, Never> {
+        return Signal { [weak base] observer in
+            guard let base = base else {
+                observer.receive(completion: .finished)
+                return SimpleDisposable(isDisposed: true)
+            }
+            let observation = base.observe(keyPath, options: options) { (base, change) in
+                observer.receive(base[keyPath: keyPath])
+            }
+            return BlockDisposable {
+                observation.invalidate()
+            }
+        }
+    }
 }
 
+
 #endif