(iOS) Fixing memory leak

Author: DimitarNestorov

ios/RCTWebViewAlternative.h

@@ -9,6 +9,10 @@
 @property (nonatomic, copy) RCTDirectEventBlock _Nullable onLoad;
 @property (nonatomic, copy) RCTDirectEventBlock _Nullable onMessage;
 
+- (nonnull instancetype)initWithFrame:(CGRect)frame NS_UNAVAILABLE;
+- (nonnull instancetype)initWithFrame:(CGRect)frame configuration:(nonnull WKWebViewConfiguration *)configuration NS_UNAVAILABLE;
+- (nullable instancetype)initWithCoder:(nonnull NSCoder *)coder NS_UNAVAILABLE;
+
 - (BOOL)scrollEnabled;
 - (void)setScrollEnabled:(BOOL)enabled;
 

ios/RCTWebViewAlternative.m

@@ -45,6 +45,17 @@ - (id)inputAccessoryView {
 
 @implementation RCTWebViewAlternative
 
+- (instancetype)init {
+    if ((self = [super init])) { // -[UIView init] calls initWithFrame:, -[WKWebView initWithFrame:] calls initWithFrame:configuration:
+        [self.configuration.userContentController addScriptMessageHandler:self name:@"jsMessageHandler"];
+    }
+    return self;
+}
+
+- (instancetype)initWithCoder:(NSCoder *)coder {
+    @throw [NSException exceptionWithName:@"Unsupported method" reason:nil userInfo:nil];
+}
+
 - (UIView *)contentView {
     UIView *contentView;
     [[self valueForKey:@"_contentView"] getValue:&contentView];
@@ -167,4 +178,14 @@ - (void)userContentController:(WKUserContentController *)userContentController d
     });
 }
 
+#pragma mark - UIView
+
+- (void)willMoveToSuperview:(UIView *)newSuperview {
+    [super willMoveToSuperview:newSuperview];
+    
+    if (newSuperview == nil) {
+        [self.configuration.userContentController removeScriptMessageHandlerForName:@"jsMessageHandler"];
+    }
+}
+
 @end

ios/WebViewAlternative.m

@@ -15,7 +15,6 @@ @implementation WebViewAlternativeManager
 - (RCTWebViewAlternative *)view {
     RCTWebViewAlternative *view = [RCTWebViewAlternative new];
     view.navigationDelegate = self;
-    [view.configuration.userContentController addScriptMessageHandler:view name:@"jsMessageHandler"];
     return view;
 }
 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "react-native-webview-alternative",
-  "version": "0.0.2",
+  "version": "0.0.3",
   "description": "Alternative to react-native-webview",
   "main": "lib/commonjs/index.js",
   "module": "lib/module/index.js",