Question by RobGillespie · Mar 22, 2021 at 07:09 PM · javascript webgl

Getting Unity WebGL to receive data from a script in a browser extension

Hi all--

I'm attempting to implement a feature whereby my Unity webGL app can print out the URLs of all the open tabs in the user's browser. I've managed to write a chrome extension that uses a background .js script to get this information and write it to the browser console. However, I can't quite figure out how to pass this information back into Unity, (or if it's even possible) since it is running in a background script in the extension and not in content script on the webpage.

I've tried using the message-passing functionality suggested by Chrome to communicate with scripts on a webpage. Here's the background js script running in the extension:

 var tabURLs = [];
 
 chrome.windows.getAll({populate:true},function(windows){
   var i=0; 
   windows.forEach(function(window){
     window.tabs.forEach(function(tab){
       //collect all of the urls here, I will just log them instead
       tabURLs.push(tab.url);
       console.log(tab.url);
       i++;
     });
   });
   console.log(i);
 });
 
 
 chrome.runtime.onMessage.addListener(
   function(request, sender, sendResponse) {
     console.log(sender.tab ?
                 "from a content script:" + sender.tab.url :
                 "from the extension");
     if (request.greeting == "hello")
       sendResponse({farewell: "goodbye"+tabURLs[0]});
   }
 );

And here's the jslib function and csharp script I tried to write to receive the data (for now I was just trying to get it to display one url just to see if I could get it working):

MessageSender.jslib:

 mergeInto(LibraryManager.library, {
     SendChromeMessage: function(){
 
     chrome.runtime.sendMessage({greeting: "hello"}, function(response) {
   console.log(response.farewell);
 
     });
 
 
 
     }
 });

Finally, the C# script I'm using to call the jslib function:

 public class JSFunctions : MonoBehaviour
 {
 
     [DllImport("__Internal")]
     public static extern void SendChromeMessage();
 
 
     public void SendURLs()
     {
         SendChromeMessage();
     }
 
 }

But when I tried running this in a webGL build, I got a whole bunch of errors: alt text