React Native WebView onMessage doesn't do anything

Question

I\'m trying to use the onMessage listener. The website is executing a postMessage (window.postMessage(\"Post message from web\");) but react native\'s webview o

Answer 1

According to this issue, you need to wait until the React Native postMessage has replaced the native window.postMessage (don’t ask me why they are replacing a native function instead of creating a new one).

One solution is to do something like:

function waitForBridge() {

   //the react native postMessage has only 1 parameter
   //while the default one has 2, so check the signature
   //of the function

   if (window.postMessage.length !== 1){
     setTimeout(waitForBridge, 200);
   }
   else {
     window.postMessage('abc');
   }
}

window.onload = waitForBridge;