An iOS bridge for sending messages to and from javascript in a UIWebView

Just open the Xcode project (requires Xcode > 4.2) and hit run to see the example application work.

See ExampleAppDelegate.* for example code. To use it in your own project:

1. Copy Classes/WebViewJavascriptBridge.h and Classes/WebViewJavascriptBridge.m into your Xcode project

2. Instantiate a UIWebView, a WebViewJavascriptBridge, and set yourself as the bridge's delegate

   #import <UIKit/UIKit.h> #import "WebViewJavascriptBridge.h"

   @interface ExampleAppDelegate : UIResponder <UIApplicationDelegate, WebViewJavascriptBridgeDelegate>

   @end

   @implementation ExampleAppDelegate

   • (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions { self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];

     self.webView = [[UIWebView alloc] initWithFrame:self.window.bounds]; [self.window addSubview:webView]; self.javascriptBridge = [WebViewJavascriptBridge javascriptBridgeWithDelegate:self]; self.webView.delegate = javascriptBridge;

     [self.window makeKeyAndVisible]; return YES; }

   • (void)javascriptBridge:(WebViewJavascriptBridge *)bridge receivedMessage:(NSString *)message fromWebView:(UIWebView *)webView { NSLog(@"MyJavascriptBridgeDelegate received message: %@", message); }

   @end

3. Go ahead and send some messages from Objc to javascript

   [self.javascriptBridge sendMessage:@"Well hello there" toWebView:self.webView];

4. Finally, set up the javascript side of things

   document.addEventListener('WebViewJavascriptBridgeReady', function onBridgeReady() { WebViewJavascriptBridge.setMessageHandler(function(message) { alert('Received message: ' + message) }) WebViewJavascriptBridge.sendMessage('Hello from the javascript') }, false)

If you're using ARC in your project, add -fno-objc-arc as a compiler flag to the WebViewJavascriptBridge.m file.

• @marcuswestin Marcus Westin
• @psineur Stepan Generalov
• @sergiocampama Sergio Campamá