Remove the error parameter from all response callbacks. This change…

… breaks API backwards compatibility!

Previously, responses were sent using either `response.respondWith(data)` or `response.respondWithError(error)`. Response handlers were then required to take two parameters:

`
function responseHandler(error, responseData) {
    if (error) { /* handle error */ }
	...
}
`

However, this approach causes confusion, as seen in GH issue marcuswestin#18. Instead, we do away with the notion of errors in responses and simply have response callback blocks with a single data parameter:

`responseCallback(data)`

and

`function responseHandler(responseData) { ... }`

To migrate from old ObjC code, simple replace all instances of `WVJBResponse* response` with `WVJBResponseCallback responseCallback`, and replace all instances of `response.respondWith(data)` with `responseCallback(data)`.

To migrate from old Javascript code, replace all instances of `response.respondWith(data)` with `response(data)`.

ExampleApp/ExampleApp.html

@@ -10,7 +10,7 @@
 	<h1>WebViewJavascriptBridge Demo</h1>
 	<script>
 	window.onerror = function(err) {
-		alert('window.onerror: ' + err)
+		log('window.onerror: ' + err)
 	}
 	document.addEventListener('WebViewJavascriptBridgeReady', onBridgeReady, false)
 	function onBridgeReady(event) {
@@ -20,24 +20,33 @@ <h1>WebViewJavascriptBridge Demo</h1>
 			var log = document.getElementById('log')
 			var el = document.createElement('div')
 			el.className = 'logLine'
-			el.innerHTML = uniqueId++ + '. ' + message + (data ? ': ' + JSON.stringify(data) : '')
+			el.innerHTML = uniqueId++ + '. ' + message + (data ? ':<br/>' + JSON.stringify(data) : '')
 			if (log.children.length) { log.insertBefore(el, log.children[0]) }
 			else { log.appendChild(el) }
 		}
-		bridge.init(function(message) {
+		bridge.init(function(message, responseCallback) {
 			log('JS got a message', message)
+			var data = { 'Javascript Responds':'Wee!' }
+			log('JS responding with', data)
+			responseCallback(data)
 		})
 
-		bridge.registerHandler('testJavascriptHandler', function(data, response) {
-			log('JS handler testJavascriptHandler was called', data)
-			response.respondWith({ 'Javascript Says':'Right back atcha!' })
+		bridge.registerHandler('testJavascriptHandler', function(data, responseCallback) {
+			log('ObjC called testJavascriptHandler with', data)
+			var responseData = { 'Javascript Says':'Right back atcha!' }
+			log('JS responding with', responseData)
+			responseCallback(responseData)
 		})
 
 		var button = document.getElementById('buttons').appendChild(document.createElement('button'))
 		button.innerHTML = 'Send message to ObjC'
 		button.ontouchstart = function(e) {
 			e.preventDefault()
-			bridge.send('Hello from JS button')
+			var data = 'Hello from JS button'
+			log('JS sending message', data)
+			bridge.send(data, function(responseData) {
+				log('JS got response', responseData)
+			})
 		}
 
 		document.body.appendChild(document.createElement('br'))
@@ -46,9 +55,9 @@ <h1>WebViewJavascriptBridge Demo</h1>
 		callbackButton.innerHTML = 'Fire testObjcCallback'
 		callbackButton.ontouchstart = function(e) {
 			e.preventDefault()
-			log("Calling handler testObjcCallback")
+			log('JS calling handler "testObjcCallback"')
 			bridge.callHandler('testObjcCallback', {'foo': 'bar'}, function(response) {
-				log('Got response from testObjcCallback', response)
+				log('JS got response', response)
 			})
 		}
 	}

ExampleApp/ExampleAppDelegate.m

@@ -12,20 +12,18 @@ - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(
 
     [WebViewJavascriptBridge enableLogging];
 
-    _bridge = [WebViewJavascriptBridge bridgeForWebView:webView handler:^(id data, WVJBResponse *response) {
+    _bridge = [WebViewJavascriptBridge bridgeForWebView:webView handler:^(id data, WVJBResponseCallback responseCallback) {
         NSLog(@"ObjC received message from JS: %@", data);
-        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"ObjC got message from Javascript:" message:data delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
-        [alert show];
+        responseCallback(@"Response for message from ObjC");
     }];
 
-    [_bridge registerHandler:@"testObjcCallback" handler:^(id data, WVJBResponse *response) {
+    [_bridge registerHandler:@"testObjcCallback" handler:^(id data, WVJBResponseCallback responseCallback) {
         NSLog(@"testObjcCallback called: %@", data);
-        [response respondWith:@"Response from testObjcCallback"];
+        responseCallback(@"Response from testObjcCallback");
     }];
 
-    [_bridge send:@"A string sent from ObjC before Webview has loaded." responseCallback:^(id error, id responseData) {
-        if (error) { return NSLog(@"Uh oh - I got an error: %@", error); }
-        NSLog(@"objc got response! %@ %@", error, responseData);
+    [_bridge send:@"A string sent from ObjC before Webview has loaded." responseCallback:^(id responseData) {
+        NSLog(@"objc got response! %@", responseData);
     }];
 
     [_bridge callHandler:@"testJavascriptHandler" data:[NSDictionary dictionaryWithObject:@"before ready" forKey:@"foo"]];
@@ -54,12 +52,15 @@ - (void)renderButtons:(UIWebView*)webView {
 }
 
 - (void)sendMessage:(id)sender {
-    [_bridge send:@"A string sent from ObjC to JS"];
+    [_bridge send:@"A string sent from ObjC to JS" responseCallback:^(id response) {
+        NSLog(@"sendMessage got response: %@", response);
+    }];
 }
 
 - (void)callHandler:(id)sender {
-    [_bridge callHandler:@"testJavascriptHandler" data:[NSDictionary dictionaryWithObject:@"Hi there, JS!" forKey:@"greetingFromObjC"] responseCallback:^(id error, id response) {
-        NSLog(@"testJavascriptHandler responded: %@ %@", error, response);
+    NSDictionary* data = [NSDictionary dictionaryWithObject:@"Hi there, JS!" forKey:@"greetingFromObjC"];
+    [_bridge callHandler:@"testJavascriptHandler" data:data responseCallback:^(id response) {
+        NSLog(@"testJavascriptHandler responded: %@", response);
     }];
 }
 

README.md

@@ -36,34 +36,32 @@ To use a WebViewJavascriptBridge in your own project:
 3) Instantiate a UIWebView and a WebViewJavascriptBridge:
 
 	UIWebView* webView = [[UIWebView alloc] initWithFrame:self.window.bounds];
-	WebViewJavascriptBridge* bridge = [WebViewJavascriptBridge bridgeForWebView:webView handler:^(id data, WVJBResponse* response) {
+	WebViewJavascriptBridge* bridge = [WebViewJavascriptBridge bridgeForWebView:webView handler:^(id data, WVJBResponseCallback responseCallback) {
 		NSLog(@"Received message from javascript: %@", data);
-		[response respondWith:@"Right back atcha"];
-		// or [response respondWithError:]
+		responseCallback(@"Right back atcha");
 	}];
 
 4) Go ahead and send some messages from ObjC to javascript:
 
 	[bridge send:@"Well hello there"];
 	[bridge send:[NSDictionary dictionaryWithObject:@"Foo" forKey:@"Bar"]];
-	[bridge send:@"Give me a response, will you?" responseCallback:^(id error, id responseData) {
-		NSLog(@"objc got its response! %@ %@", error, responseData);
+	[bridge send:@"Give me a response, will you?" responseCallback:^(id responseData) {
+		NSLog(@"ObjC got its response! %@ %@", responseData);
 	}];
 
 4) Finally, set up the javascript side:
 
 	document.addEventListener('WebViewJavascriptBridgeReady', function onBridgeReady(event) {
 		var bridge = event.bridge
-		bridge.init(function(message, response) {
+		bridge.init(function(message, responseCallback) {
 			alert('Received message: ' + message)   
-			if (response) {
-				response.respondWith("Right back atcha")
-				// or use response.respondWithError("Booh!")
+			if (responseCallback) {
+				responseCallback("Right back atcha")
 			}
 		})
 		bridge.send('Hello from the javascript')
-		bridge.send('Please respond to this', function responseCallback(error, responseData) {
-			console.log("javascript got its response", error, responseData)
+		bridge.send('Please respond to this', function responseCallback(responseData) {
+			console.log("Javascript got its response", responseData)
 		})
 	}, false)
 
@@ -77,20 +75,20 @@ API Reference
 
 Create a javascript bridge for the given UIWebView.
 
-The `WVJBResponse` will not be `nil` if the javascript expects a response.
+The `WVJBResponseCallback` will not be `nil` if the javascript expects a response.
 
 Optionally, pass in `webViewDelegate:(UIWebViewDelegate*)webViewDelegate` if you need to respond to the [UIWebView's lifecycle events](http://developer.apple.com/library/ios/documentation/uikit/reference/UIWebViewDelegate_Protocol/Reference/Reference.html).
 
 Example:
 
-	[WebViewJavascriptBridge bridgeForWebView:webView handler:^(id data, WVJBResponse response) {
+	[WebViewJavascriptBridge bridgeForWebView:webView handler:^(id data, WVJBResponseCallback responseCallback) {
 		NSLog(@"Received message from javascript: %@", data);
-		if (response) {
-			[response respondWith:@"Right back atcha"];
+		if (responseCallback) {
+			responseCallback(@"Right back atcha");
 		}
 	}]
 
-	[WebViewJavascriptBridge bridgeForWebView:webView webViewDelegate:self handler:^(id data, WVJBResponse response) { /* ... */ }];
+	[WebViewJavascriptBridge bridgeForWebView:webView webViewDelegate:self handler:^(id data, WVJBResponseCallback responseCallback) { /* ... */ }];
 
 ##### `[bridge send:(id)data]`
 ##### `[bridge send:(id)data responseCallback:(WVJBResponseCallback)responseCallback]`
@@ -101,8 +99,7 @@ Example:
 
 	[bridge send:@"Hi"];
 	[bridge send:[NSDictionary dictionaryWithObject:@"Foo" forKey:@"Bar"]];
-	[bridge send:@"I expect a response!" responseCallback:^(id error, id responseData) {
-		if (error) { return NSLog(@"Uh oh, I got an error: %@", error); }
+	[bridge send:@"I expect a response!" responseCallback:^(id responseData) {
 		NSLog(@"Got response! %@", responseData);
 	}];
 
@@ -112,8 +109,8 @@ Register a handler called `handlerName`. The javascript can then call this handl
 
 Example:
 
-	[bridge registerHandler:@"getScreenHeight" handler:^(id data, WVJBResponse response) {
-		[response respondWith:[NSNumber numberWithInt:[UIScreen mainScreen].bounds.size.height]];
+	[bridge registerHandler:@"getScreenHeight" handler:^(id data, WVJBResponseCallback responseCallback) {
+		responseCallback([NSNumber numberWithInt:[UIScreen mainScreen].bounds.size.height]);
 	}];
 
 ##### `[bridge callHandler:(NSString*)handlerName data:(id)data]`
@@ -124,8 +121,7 @@ Call the javascript handler called `handlerName`. Optionally expect a response b
 Example:
 
 	[bridge callHandler:@"showAlert" data:@"Hi from ObjC to JS!"];
-	[bridge callHandler:@"getCurrentPageUrl" data:nil responseCallback:^(id error, id responseData) {
-		if (error) { return NSLog(@"Huston, we got a problem: %@", error); }
+	[bridge callHandler:@"getCurrentPageUrl" data:nil responseCallback:^(id responseData) {
 		NSLog(@"Current UIWebView page URL is: %@", responseData);
 	}];
 
@@ -153,37 +149,35 @@ The `response` object will be defined if if ObjC sent the message with a `WVJBRe
 
 Example:
 
-	bridge.init(function(data, response) {
+	bridge.init(function(data, responseCallback) {
 		alert("Got data " + JSON.stringify(data))
-		if (response) {
-			response.respondWith("Right back atcha!")
-			// or, response.respondWithError("It went wrong!")
+		if (responseCallback) {
+			responseCallback("Right back atcha!")
 		}
 	})
 
 ##### `bridge.send("Hi there!")`
 ##### `bridge.send({ Foo:"Bar" })`
-##### `bridge.send(data, function responseCallback(error, responseData) { ... })`
+##### `bridge.send(data, function responseCallback(responseData) { ... })`
 
 Send a message to ObjC. Optionally expect a response by giving a `responseCallback` function.
 
 Example:
 
 	bridge.send("Hi there!")
-	bridge.send("Hi there!", function(error, responseData) {
-		if (error) { return alert("Uh oh, we got an error: "+error) }
-		alert("I got a response! "+JSON.stringify(data))
+	bridge.send("Hi there!", function(responseData) {
+		alert("I got a response! "+JSON.stringify(responseData))
 	})
 
-##### `bridge.registerHandler("handlerName", function(error, responseData) { ... })`
+##### `bridge.registerHandler("handlerName", function(responseData) { ... })`
 
-Register a handler called `handlerName`. The ObjC can then call this handler with `[bridge callHandler:"handlerName" data:@"Foo"]` and `[bridge callHandler:"handlerName" data:@"Foo" responseCallback:^(id error, id responseData) { ... }]`
+Register a handler called `handlerName`. The ObjC can then call this handler with `[bridge callHandler:"handlerName" data:@"Foo"]` and `[bridge callHandler:"handlerName" data:@"Foo" responseCallback:^(id responseData) { ... }]`
 
 Example:
 
 	bridge.registerHandler("showAlert", function(data) { alert(data) })
-	bridge.registerHandler("getCurrentPageUrl", function(data, response) {
-		response.respondWith(document.location.toString())
+	bridge.registerHandler("getCurrentPageUrl", function(data, responseCallback) {
+		responseCallback(document.location.toString())
 	})
 
 

WebViewJavascriptBridge/WebViewJavascriptBridge.h

@@ -1,8 +1,7 @@
 #import <UIKit/UIKit.h>
 
-@class WVJBResponse;
-typedef void (^WVJBResponseCallback)(id error, id responseData);
-typedef void (^WVJBHandler)(id data, WVJBResponse* response);
+typedef void (^WVJBResponseCallback)(id responseData);
+typedef void (^WVJBHandler)(id data, WVJBResponseCallback responseCallback);
 
 @interface WebViewJavascriptBridge : NSObject <UIWebViewDelegate>
 + (id)bridgeForWebView:(UIWebView*)webView handler:(WVJBHandler)handler;
@@ -16,9 +15,3 @@ typedef void (^WVJBHandler)(id data, WVJBResponse* response);
 - (void)callHandler:(NSString*)handlerName data:(id)data responseCallback:(WVJBResponseCallback)responseCallback;
 - (void)reset;
 @end
-
-@interface WVJBResponse : NSObject
-- (WVJBResponse*) initWithCallbackId:(NSString*)callbackId bridge:(WebViewJavascriptBridge*)bridge;
-- (void) respondWith:(id)responseData;
-- (void) respondWithError:(id)error;
-@end

WebViewJavascriptBridge/WebViewJavascriptBridge.js.txt

@@ -63,19 +63,14 @@
 
 			if (message.responseId) {
 				var responseCallback = responseCallbacks[message.responseId]
-				responseCallback(message.error, message.responseData)
+				responseCallback(message.responseData)
 				delete responseCallbacks[message.responseId]
 			} else {
-				var response
+				var responseCallback
 				if (message.callbackId) {
 					var callbackResponseId = message.callbackId
-					response = {
-						respondWith: function(responseData) {
-							_doSend({ responseId:callbackResponseId, responseData:responseData })
-						},
-						respondWithError: function(error) {
-							_doSend({ responseId:callbackResponseId, error:error })
-						}
+					responseCallback = function(responseData) {
+						_doSend({ responseId:callbackResponseId, responseData:responseData })
 					}
 				}
 
@@ -85,9 +80,11 @@
 				}
 
 				try {
-					handler(message.data, response)
+					handler(message.data, responseCallback)
 				} catch(exception) {
-					console.log("WebViewJavascriptBridge: WARNING: javascript handler threw.", message, exception)
+					if (typeof console != 'undefined') {
+						console.log("WebViewJavascriptBridge: WARNING: javascript handler threw.", message, exception)
+					}
 				}
 			}
 		})