postMessage support?

I noticed the APIs in CustomTabService for using postMessage, but I couldn’t get them to work. And after some searching around I found this patch, suggesting that postMessage is disabled in TWAs:

https://chromium.googlesource.com/chromium/src/+/20891520570f780b13ae9725d9aa5a909338d0a9^!/

But it was back in 2018, so I wanted to check: can I use the native postMessage APIs with TWAs? If not, are there any other strategies for transferring data between the native and web sides?

[FluorescentHallucinogen]

@andreban I need to implement background geolocation in my TWA. Since background geolocation is currently not supported in Web, I plan to implement it natively. But I need to somehow pass geolocation coordinates from native code to JavaScript code every X seconds. The first idea that came to my mind is to pass geolocation coordinates via URL query parameters. But looks like it’s not a good idea, because changing URL query parameters leads to page reload. Right? Moreover, actually I need to pass the data into service worker, not into the page (because this should work in the background). What is the best way to pass data from native code to JS code in my case? Any ideas and code samples will be appreciated.

[lokario]

I have a similar use case.

I have a background service implemented in the native android project, so every now and then I want to send data from native code into javascript.

@PEConn @andreban do you think this could be done by using Web Share API?

I tried triggering an “ACTION_SEND” intent on the native side, and registering on the javascript as if it was a Web Share Target, but it didn’t work (maybe I didn’t get the idea).

I’m following these articles/tutorials: https://developers.google.com/web/android/trusted-web-activity/web-share-target https://web.dev/web-share-target/ https://developer.android.com/training/sharing/send#send-text-content

This is the android code (within service), it has Notification Delegation enabled:

Intent sharingIntent = new Intent(Intent.ACTION_SEND);
sharingIntent.setType("text/plain");
sharingIntent.setData(Uri.parse("https://<myappdomain>.com/share-target/"));
sharingIntent.putExtra(Intent.EXTRA_TEXT, "Some text");
sharingIntent.putExtra(Intent.EXTRA_TITLE, "Some title");
startActivity(sharingIntent);

On the web project I added this into manifest.json:

  "share_target": {
    "name": "NotificationListener",
    "action": "/share-target/",
    "method": "POST",
    "enctype": "text/plain",
    "params": {
      "title": "title",
      "text": "text",
      "url": "url"
    }
  },

and on javascript side:

self.addEventListener('fetch', (event) => {
  event.waitUntil(self.registration.showNotification('Code invoked by native'));
});

but the fetch is never called.

@AlissonRS Did you find a way to get it to work?