Exported a callback for native webview delegate method webview:shouldStartLoadWithRequest:navigationType:

Author: pjcabrera

Libraries/Components/WebView/WebView.ios.js

@@ -107,6 +107,7 @@ var WebView = React.createClass({
      * user can change the scale
      */
     scalesPageToFit: PropTypes.bool,
+    shouldStartLoadWithRequest: PropTypes.func,
   },
 
   getInitialState: function() {
@@ -167,6 +168,7 @@ var WebView = React.createClass({
         onLoadingStart={this.onLoadingStart}
         onLoadingFinish={this.onLoadingFinish}
         onLoadingError={this.onLoadingError}
+        onShouldStartLoadWithRequest={this.onShouldStartLoadWithRequest}
         scalesPageToFit={this.props.scalesPageToFit}
       />;
 
@@ -178,6 +180,10 @@ var WebView = React.createClass({
     );
   },
 
+  startLoadWithResult: function(result, lockIdentifier) {
+    RCTWebViewManager.startLoadWithResult(result, lockIdentifier);
+  },
+
   goForward: function() {
     RCTWebViewManager.goForward(this.getWebViewHandle());
   },
@@ -224,13 +230,20 @@ var WebView = React.createClass({
     });
     this.updateNavigationState(event);
   },
+
+  onShouldStartLoadWithRequest: function(event: Event) {
+    if (this.props.shouldStartLoadWithRequest) {
+      this.props.shouldStartLoadWithRequest(event.nativeEvent);
+    }
+  },
 });
 
 var RCTWebView = requireNativeComponent('RCTWebView', WebView, {
   nativeOnly: {
     onLoadingStart: true,
     onLoadingError: true,
     onLoadingFinish: true,
+    onShouldStartLoadWithRequest: true
   },
 });
 

React/Views/RCTWebView.m

@@ -25,6 +25,10 @@ @interface RCTWebView () <UIWebViewDelegate, RCTAutoInsetsProtocol>
 @property (nonatomic, copy) RCTDirectEventBlock onLoadingStart;
 @property (nonatomic, copy) RCTDirectEventBlock onLoadingFinish;
 @property (nonatomic, copy) RCTDirectEventBlock onLoadingError;
+@property (nonatomic, copy) RCTDirectEventBlock onShouldStartLoadWithRequest;
+@property (nonatomic, strong) NSConditionLock *conditionLock;
+@property (nonatomic, assign) BOOL startLoadResult;
+@property (nonatomic, strong) NSOperationQueue *operationQueue;
 
 @end
 
@@ -43,6 +47,8 @@ - (instancetype)initWithFrame:(CGRect)frame
     _webView = [[UIWebView alloc] initWithFrame:self.bounds];
     _webView.delegate = self;
     [self addSubview:_webView];
+
+    self.operationQueue = [[NSOperationQueue alloc] init];
   }
   return self;
 }
@@ -142,6 +148,16 @@ - (void)refreshContentInset
 - (BOOL)webView:(__unused UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request
  navigationType:(UIWebViewNavigationType)navigationType
 {
+  // skip this for the JS Navigation handler
+  if (![request.URL.scheme isEqualToString:RCTJSNavigationScheme] &&
+      _onShouldStartLoadWithRequest) {
+    NSMutableDictionary *event = [self baseEvent];
+    [event addEntriesFromDictionary: @{
+      @"url": (request.URL).absoluteString,
+       @"navigationType": @(navigationType)
+    }];
+    return [self onShouldStartLoadWithRequest:event];
+  }
   if (_onLoadingStart) {
     // We have this check to filter out iframe requests and whatnot
     BOOL isTopFrame = [request.URL isEqual:request.mainDocumentURL];
@@ -159,6 +175,34 @@ - (BOOL)webView:(__unused UIWebView *)webView shouldStartLoadWithRequest:(NSURLR
   return ![request.URL.scheme isEqualToString:RCTJSNavigationScheme];
 }
 
+- (BOOL)onShouldStartLoadWithRequest:(NSMutableDictionary *)event {
+  id observer = [[NSNotificationCenter defaultCenter] addObserverForName:@"webViewStartLoadNotification" object:nil queue:self.operationQueue usingBlock:^(NSNotification * _Nonnull note) {
+    NSDictionary *userInfo = note.userInfo;
+    
+    NSInteger lockIdentifier = ((NSNumber *)userInfo[@"lockIdentifier"]).longValue;
+    self.startLoadResult = ((NSNumber *)userInfo[@"result"]).boolValue;
+    
+    [self.conditionLock unlockWithCondition:lockIdentifier];
+    self.conditionLock = nil;
+  }];
+  
+  NSInteger lockIdentifier = arc4random();
+  self.conditionLock = [[NSConditionLock alloc] initWithCondition:lockIdentifier];
+  [self.conditionLock lock];
+  
+  [event addEntriesFromDictionary: @{
+    @"lockIdentifier": @(lockIdentifier)
+  }];
+  _onShouldStartLoadWithRequest(event);
+
+  [self.conditionLock lockBeforeDate:[NSDate dateWithTimeIntervalSinceNow:1]];
+
+  [[NSNotificationCenter defaultCenter] removeObserver:observer];
+
+  return self.startLoadResult;
+}
+
+
 - (void)webView:(__unused UIWebView *)webView didFailLoadWithError:(NSError *)error
 {
   if (_onLoadingError) {

React/Views/RCTWebViewManager.m

@@ -34,6 +34,7 @@ - (UIView *)view
 RCT_EXPORT_VIEW_PROPERTY(onLoadingStart, RCTDirectEventBlock);
 RCT_EXPORT_VIEW_PROPERTY(onLoadingFinish, RCTDirectEventBlock);
 RCT_EXPORT_VIEW_PROPERTY(onLoadingError, RCTDirectEventBlock);
+RCT_EXPORT_VIEW_PROPERTY(onShouldStartLoadWithRequest, RCTDirectEventBlock);
 
 - (NSDictionary *)constantsToExport
 {
@@ -50,6 +51,14 @@ - (NSDictionary *)constantsToExport
   };
 }
 
+RCT_EXPORT_METHOD(startLoadWithResult:(BOOL)result lockIdentifier:(NSInteger)lockIdentifier) {
+  NSDictionary *userInfo = @{
+    @"result": @(result),
+    @"lockIdentifier": @(lockIdentifier)
+  };
+  [[NSNotificationCenter defaultCenter] postNotificationName:@"webViewStartLoadNotification" object:self userInfo:userInfo];
+}
+
 RCT_EXPORT_METHOD(goBack:(nonnull NSNumber *)reactTag)
 {
   [self.bridge.uiManager addUIBlock:^(__unused RCTUIManager *uiManager, RCTSparseArray *viewRegistry) {