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Cross domain messaging in Opera Mini

  • I have implemented a cross domain messaging between the main page and an iframe. It works on all browsers except for Opera Mini.

    The parent page has the following code:

    if (window.addEventListener) {
        window.addEventListener("message", function(event) { alert(;}, false);
    } else if (window.attachEvent) {
        window.attachEvent("onmessage", function(event) { alert(;});

    The iframe page has this code:

    window.parent.postMessage('test', '*');

    When the iframe tries to access window.parent to execute the postMessage method Opera Mini throws an exception: 'Security error: attempted to read protected variable'. All other browsers will not complain.

    See example here:

    Is there a workaround?

  • Thanks for your report and providing the code snippets. I'm happy to tell you that we managed to find the root cause of this issue and the fix is awaiting deployment. It should be live either this or next week unless it causes some other nasty bugs to appear here and there 🙂 I'll keep you posted.

  • @queueitmala: Should be okey now - can you verify if it works for you?

  • I can verify both the example and our application is working. I got some errors in our log on the 17th, but I suppose the update has to be pushed out first. Thank you.