postWebMessage method

@override Future<void> postWebMessage({ required WebMessage message, WebUri? targetOrigin, })

Post a message to main frame. The embedded application can restrict the messages to a certain target origin. See HTML5 spec for how target origin can be used.

A target origin can be set as a wildcard ("*"). However this is not recommended.

Officially Supported Platforms/Implementations:

• Android WebView (Official API - WebView.postWebMessage):
  • This method should only be called if WebViewFeature.isFeatureSupported returns true for WebViewFeature.POST_WEB_MESSAGE.
• iOS WKWebView:
  • This method is implemented using JavaScript.
• macOS WKWebView:
  • This method is implemented using JavaScript.
• Linux WPE WebKit:
  • Implemented via JavaScript MessageChannel API.
• Windows WebView2:
  • Implemented via JavaScript MessageChannel API.

Parameters - Officially Supported Platforms/Implementations:

• message: all platforms
• targetOrigin: all platforms

Use the PlatformInAppWebViewController.isMethodSupported method to check if this method is supported at runtime.

Implementation

@override
Future<void> postWebMessage({
  required WebMessage message,
  WebUri? targetOrigin,
}) async {
  if (targetOrigin == null) {
    targetOrigin = WebUri('');
  }
  Map<String, dynamic> args = <String, dynamic>{};
  args.putIfAbsent('message', () => message.toMap());
  args.putIfAbsent('targetOrigin', () => targetOrigin.toString());
  await channel?.invokeMethod('postWebMessage', args);
}