Message Listener Only Receives "{isTrusted: true}" Object

The webpage rendered inside webview only receives {isTrusted: true} when receiving events.

This issue can be reproduced by adding the following code to the webage that attaches a function to the message event: window.addEventListener('message', this.handleMessage);

In the webview, I activate the message event using the injectJavaScript method like this this.webview.injectJavaScript(window.postMessage(${stringMessage}, ‘*’); true;)

where stringMessage is as JSON.stringified object

Expected behavior: I expected the entire stringified object to be received as a variable in the handleMessage function. Instead, I only receive the {isTrusted: true}

Environment:

• OS: Windows, Android OnePlus 5
• OS version: 10
• react-native version: 0.59.8 using Expo https://github.com/expo/react-native/archive/sdk-33.0.0.tar.gz
• react-native-webview version: 5.12.0

[rgoldiez]

@reggie3 … Humor me and trying changing this.addDebugMessage({event}) to this.addDebugMessage(event.data)

[LindaOjo]

Solutions above didn’t work for me.

What worked for me.

I had a false false report. WebView logs {isTrusted: false} when the event data is from an “untrusted source”. Even though the data is as expected.

console.log(data) // {isTrusted: false}

Ignoring the log and treating the data as expected (assuming the correct data was logged) worked for me.