Chromecast cannot receive custom messages (CAF Receiver) - chromecast

Question

I am working with react native wrapper for Google Cast SDK and I couldn't send a message from the sender to receiver. I am able to cast media or pause and resume it. The problem is only about custom messages. My custom message listener is never called in the receiver side. Should the message have a specific structure that I am missing? Thanks in advance.
Sender:
GoogleCast.initChannel('urn:x-cast:testChannel');
GoogleCast.sendMessage('urn:x-cast:testChannel', 'testMessage');
Receiver:
const context = cast.framework.CastReceiverContext.getInstance();
const CUSTOM_CHANNEL = 'urn:x-cast:testChannel';
context.addCustomMessageListener(CUSTOM_CHANNEL, function(customEvent) {
// handle customEvent.
console.log('event received');
});
Edit: I am able to send message from receiver to sender:
Receiver:
context.sendCustomMessage(CUSTOM_CHANNEL , undefined, 'myMessage');
Sender:
GoogleCast.EventEmitter.addListener(GoogleCast.CHANNEL_MESSAGE_RECEIVED, ({undefined, message}) => {
console.log(message);
});

Answer 1

I think this is problem bellow
https://issuetracker.google.com/issues/117136854#comment7
So try this...
Send
let message = {msg: 'testMessage'};
message = JSON.stringify(message);
GoogleCast.sendMessage('urn:x-cast:testChannel', message);
and Receiver
const CHANNEL = 'urn:x-cast:testChannel';
const ctx = cast.framework.CastReceiverContext.getInstance();
const options = new cast.framework.CastReceiverOptions();
const objToSender =
{
type: 'status',
message: 'Playing'
};
options.customNamespaces = Object.assign({});
options.customNamespaces[CHANNEL] = cast.framework.system.MessageType.JSON;
//receiving sender message
ctx.addCustomMessageListener(CHANNEL, customEvent => document.getElementById("main").innerHTML = customEvent.data.msg);
//message to sender app
ctx.sendCustomMessage(CHANNEL, objToSender);
ctx.start(options);