fix retain cycle

Author: Peyton Randolph

WebViewJavascriptBridgeAbstract/WebViewJavascriptBridgeAbstract.h

@@ -7,8 +7,8 @@ typedef void (^WVJBHandler)(id data, WVJBResponseCallback responseCallback);
 
 @interface WebViewJavascriptBridgeAbstract : NSObject
 
-@property (nonatomic, strong) id webView;
-@property (nonatomic, strong) id webViewDelegate;
+@property (nonatomic, weak) id webView;
+@property (nonatomic, weak) id webViewDelegate;
 @property (nonatomic, strong) NSMutableArray *startupMessageQueue;
 @property (nonatomic, strong) NSMutableDictionary *responseCallbacks;
 @property (nonatomic, strong) NSMutableDictionary *messageHandlers;

WebViewJavascriptBridgeAbstract/WebViewJavascriptBridgeAbstract.m

@@ -79,21 +79,23 @@ - (void)_dispatchMessage:(NSDictionary *)message {
     messageJSON = [messageJSON stringByReplacingOccurrencesOfString:@"\n" withString:@"\\n"];
     messageJSON = [messageJSON stringByReplacingOccurrencesOfString:@"\r" withString:@"\\r"];
     messageJSON = [messageJSON stringByReplacingOccurrencesOfString:@"\f" withString:@"\\f"];
+    __strong typeof(self.webView) strongWebView = self.webView;
     if ([[NSThread currentThread] isMainThread]) {
-        [self.webView performSelector:@selector(stringByEvaluatingJavaScriptFromString:)
+        [strongWebView performSelector:@selector(stringByEvaluatingJavaScriptFromString:)
                            withObject:[NSString stringWithFormat:
                                        @"WebViewJavascriptBridge._handleMessageFromObjC('%@');", messageJSON]];
     } else {
         dispatch_sync(dispatch_get_main_queue(), ^{
-            [self.webView performSelector:@selector(stringByEvaluatingJavaScriptFromString:)
+            [strongWebView performSelector:@selector(stringByEvaluatingJavaScriptFromString:)
                                withObject:[NSString stringWithFormat:
                                            @"WebViewJavascriptBridge._handleMessageFromObjC('%@');", messageJSON]];
         });
     }
 }
 
 - (void)_flushMessageQueue {
-    NSString *messageQueueString = [self.webView performSelector:
+    __strong typeof(self.webView) strongWebView = self.webView;
+    NSString *messageQueueString = [strongWebView performSelector:
                                     @selector(stringByEvaluatingJavaScriptFromString:) withObject:@"WebViewJavascriptBridge._fetchQueue();"];
 
     NSArray* messages = [messageQueueString componentsSeparatedByString:kMessageSeparator];
@@ -112,8 +114,8 @@ - (void)_flushMessageQueue {
             __block NSString* callbackId = message[@"callbackId"];
             if (callbackId) {
                 responseCallback = ^(id responseData) {
-                    NSDictionary* message = @{ @"responseId":callbackId, @"responseData":responseData };
-                    [self _queueMessage:message];
+                    NSDictionary* msg = @{ @"responseId":callbackId, @"responseData":responseData };
+                    [self _queueMessage:msg];
                 };
             } else {
                 responseCallback = ^(id ignoreResponseData) {

WebViewJavascriptBridge_iOS/WebViewJavascriptBridge_iOS.h

@@ -3,8 +3,8 @@
 
 @interface WebViewJavascriptBridge : WebViewJavascriptBridgeAbstract <UIWebViewDelegate>
 
-@property (nonatomic, strong) UIWebView *webView;
-@property (nonatomic, strong) id <UIWebViewDelegate> webViewDelegate;
+@property (nonatomic, weak) UIWebView *webView;
+@property (nonatomic, weak) id <UIWebViewDelegate> webViewDelegate;
 
 + (id)bridgeForWebView:(UIWebView*)webView handler:(WVJBHandler)handler;
 + (id)bridgeForWebView:(UIWebView*)webView webViewDelegate:(id <UIWebViewDelegate>)webViewDelegate handler:(WVJBHandler)handler;

WebViewJavascriptBridge_iOS/WebViewJavascriptBridge_iOS.m

@@ -24,10 +24,10 @@ + (id)bridgeForWebView:(UIWebView *)webView webViewDelegate:(id<UIWebViewDelegat
 - (void)webViewDidFinishLoad:(UIWebView *)webView {
     if (webView != self.webView) { return; }
 
-    if (![[self.webView stringByEvaluatingJavaScriptFromString:@"typeof WebViewJavascriptBridge == 'object'"] isEqualToString:@"true"]) {
+    if (![[webView stringByEvaluatingJavaScriptFromString:@"typeof WebViewJavascriptBridge == 'object'"] isEqualToString:@"true"]) {
         NSString *filePath = [[NSBundle mainBundle] pathForResource:@"WebViewJavascriptBridge.js" ofType:@"txt"];
         NSString *js = [NSString stringWithContentsOfFile:filePath encoding:NSUTF8StringEncoding error:nil];
-        [self.webView stringByEvaluatingJavaScriptFromString:js];
+        [webView stringByEvaluatingJavaScriptFromString:js];
     }
 
     if (self.startupMessageQueue) {
@@ -37,39 +37,43 @@ - (void)webViewDidFinishLoad:(UIWebView *)webView {
         self.startupMessageQueue = nil;
     }
 
-    if (self.webViewDelegate && [self.webViewDelegate respondsToSelector:@selector(webViewDidFinishLoad:)]) {
-        [self.webViewDelegate webViewDidFinishLoad:webView];
+    __strong typeof(self.webViewDelegate) strongDelegate = self.webViewDelegate;
+    if (strongDelegate && [strongDelegate respondsToSelector:@selector(webViewDidFinishLoad:)]) {
+        [strongDelegate webViewDidFinishLoad:webView];
     }
 }
 
 - (void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error {
     if (webView != self.webView) { return; }
-    if (self.webViewDelegate && [self.webViewDelegate respondsToSelector:@selector(webView:didFailLoadWithError:)]) {
-        [self.webViewDelegate webView:self.webView didFailLoadWithError:error];
+    __strong typeof(self.webViewDelegate) strongDelegate = self.webViewDelegate;
+    if (strongDelegate && [strongDelegate respondsToSelector:@selector(webView:didFailLoadWithError:)]) {
+        [strongDelegate webView:webView didFailLoadWithError:error];
     }
 }
 
 - (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType {
     if (webView != self.webView) { return YES; }
     NSURL *url = [request URL];
+    __strong typeof(self.webViewDelegate) strongDelegate = self.webViewDelegate;
     if ([[url scheme] isEqualToString:kCustomProtocolScheme]) {
         if ([[url host] isEqualToString:kQueueHasMessage]) {
             [self _flushMessageQueue];
         } else {
             NSLog(@"WebViewJavascriptBridge: WARNING: Received unknown WebViewJavascriptBridge command %@://%@", kCustomProtocolScheme, [url path]);
         }
         return NO;
-    } else if (self.webViewDelegate && [self.webViewDelegate respondsToSelector:@selector(webView:shouldStartLoadWithRequest:navigationType:)]) {
-        return [self.webViewDelegate webView:webView shouldStartLoadWithRequest:request navigationType:navigationType];
+    } else if (strongDelegate && [strongDelegate respondsToSelector:@selector(webView:shouldStartLoadWithRequest:navigationType:)]) {
+        return [strongDelegate webView:webView shouldStartLoadWithRequest:request navigationType:navigationType];
     } else {
         return YES;
     }
 }
 
 - (void)webViewDidStartLoad:(UIWebView *)webView {
     if (webView != self.webView) { return; }
-    if (self.webViewDelegate && [self.webViewDelegate respondsToSelector:@selector(webViewDidStartLoad:)]) {
-        [self.webViewDelegate webViewDidStartLoad:webView];
+    __strong typeof(self.webViewDelegate) strongDelegate = self.webViewDelegate;
+    if (strongDelegate && [strongDelegate respondsToSelector:@selector(webViewDidStartLoad:)]) {
+        [strongDelegate webViewDidStartLoad:webView];
     }
 }