Adds error handling during `bindNext`.

RxCocoa/Common/Observable+Bind.swift

@@ -16,7 +16,8 @@ extension ObservableType {
     /**
     Creates new subscription and sends elements to observer.
     
-    In this form it's equivalent to `subscribe` method, but it communicates intent better.
+    In this form it's equivalent to `subscribe` method, but it communicates intent better, and enables
+    writing more consistent binding code.
     
     - parameter observer: Observer that receives events.
     - returns: Disposable object that can be used to unsubscribe the observer.
@@ -29,8 +30,8 @@ extension ObservableType {
     /**
     Creates new subscription and sends elements to variable.
 
-    In release mode error will be logged in case attempting to bind an error to variable.
-    In debug mode exception will be thrown in case attempting to bind error to variable.
+    In case error occurs in debug mode, `fatalError` will be raised.
+    In case error occurs in release mode, `error` will be logged.
 
     - parameter variable: Target variable for sequence elements.
     - returns: Disposable object that can be used to unsubscribe the observer.
@@ -42,7 +43,12 @@ extension ObservableType {
             case let .Next(element):
                 variable.value = element
             case let .Error(error):
-                bindingErrorToVariable(error)
+                let error = "Binding error to variable: \(error)"
+            #if DEBUG
+                rxFatalError(error)
+            #else
+                print(error)
+            #endif
             case .Completed:
                 break
             }
@@ -79,13 +85,23 @@ extension ObservableType {
     
     
     /**
-    Subscribes an element handler to an observable sequence.
+    Subscribes an element handler to an observable sequence. 
+
+    In case error occurs in debug mode, `fatalError` will be raised.
+    In case error occurs in release mode, `error` will be logged.
     
     - parameter onNext: Action to invoke for each element in the observable sequence.
     - returns: Subscription object used to unsubscribe from the observable sequence.
     */
     @warn_unused_result(message="http://git.io/rxs.ud")
     public func bindNext(onNext: E -> Void) -> Disposable {
-        return subscribeNext(onNext)
+        return subscribe(onNext: onNext, onError: { error in
+            let error = "Binding error to variable: \(error)"
+            #if DEBUG
+                rxFatalError(error)
+            #else
+                print(error)
+            #endif
+        })
     }
 }

RxCocoa/Common/RxCocoa.swift

@@ -228,15 +228,6 @@ func bindingErrorToInterface(error: ErrorType) {
 #endif
 }
 
-func bindingErrorToVariable(error: ErrorType) {
-    let error = "Binding error to variable: \(error)"
-#if DEBUG
-    rxFatalError(error)
-#else
-    print(error)
-#endif
-}
-
 // MARK: Abstract methods
 
 @noreturn func rxAbstractMethodWithMessage(message: String) {