Returning a Media Stream from a Native Module

[p8952]

Description

When defining a Native Module that calls getUserMedia, I am unable to pass the resulting Media Stream back to index.js.

Expected behavior

When the Promise in my Native Module resolves with a Media Stream, that Media Stream will be available in index.js.

Actual behavior

When the Promise in my Native Module resolves with a Media Stream, that Media Stream is not available in index.js, instead it is an empty object.

Reproduction

Native Module:

  $getUserMedia(resolveID, rejectID) {
    navigator.mediaDevices
      .getUserMedia({ audio: true, video: true })
      .then((mediaStream) => {
        console.log(mediaStream);
        this._ctx.invokeCallback(resolveID, [mediaStream]);
      })
      .catch((error) => {
        this._ctx.invokeCallback(rejectID, [error]);
      });
  }

Logs: MediaStream {id: "Efr55Nh1C0n9H5heZTk5NMi1CaEYnbSPsFYQ", active: true, onaddtrack: null, onremovetrack: null, onactive: null, …}

index.js:

    WebRTCNativeModule.getUserMedia().then((mediaStream) => {
      console.log(mediaStream);
    });

Logs: {}

Additional Information

• 'react-360' package version: react-360@1.1.0
• 'react-360-web' package version: react-360-web@1.1.0
• Operating System: Linux (Fedora 27)
• Browser: Chrome 72 (Desktop)
• VR Device: N/A - In Chrome (Desktop)

[larrylin28]

You can not do this. The index.js is running in a web worker, and all messages sent via NativeModule to it is JSON stringed and sent via postMessage, a mediaStream is not able to stringify to a JSON.
Despite from that, why would you want to send a media stream to react side(index.js)?
If you want some information about the stream to be used by react code, please extract those properties out and send them instead.
If you want to play the media, you can't directly play the media on react side(index.js). You should do it on client side(client.js). E.g, save the media stream in your native module, and then use native module function call from react side to trigger the playing or other controls that runs in native module.

[p8952]

Thanks @larrylin28, fair enough if it's a postMessage and can only send JSON.

I have a couple of further questions regarding videos, surfaces, screens. Do you have a Slack channel or anything? Or can I ask here?