Forwarding/handling messages in Opera 11 extensions

R

revol0ution2010-12-19 13:40:32

Opera

revol0ution, 2010-12-19 13:40:32

After reading Extensions for Opera: Messaging decided to check it out.

Background script (index.html):


<!doctype html>
<html lang="en">
    <head>
        <script>
            window.addEventListener('load', function(){
                var button = opera.contexts.toolbar.createItem({ title: 'Send message', icon: 'icons/message.png' })

                button.addEventListener('click', function(event) {
                    var tab = opera.extension.tabs.getFocused();
                    if (tab)
                        tab.postMessage({}); // можно попробовать и opera.extension.broadcastMessage({});
                }, false);

                opera.contexts.toolbar.addItem(button);
            }, false);
        </script>
    </head>
    <body>
    </body>
</html>

Injected script:


(function () {
    var storedLocation = '';

    if (opera.extension !== undefined) {
        opera.extension.onmessage = function(event){
            opera.postError('got message: ' + storedLocation);
        };
    }
    
    window.opera.addEventListener("BeforeEvent.DOMContentLoaded", function (event) {
        storedLocation = window.location.href;
        opera.postError('loaded: ' + storedLocation);
    }, false);
})()

The first thing I noticed is that the BeforeEvent.DOMContentLoaded handler often executes more than once when opening a new page.

Obviously the cause is an iframe with ads.

Okay, but if we click the button now, then... The message gets a background script with ads, but I would like something completely different.

It is clear that using broadcastMessage() to send will "deliver" the message to the background script of the main page, but scripts from other tabs will also receive it.

How to solve the problem of delivering a message to a script on the active tab of the "main" page?

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2 answer(s)

R

revol0ution, 2010-12-28
@revol0ution

Thanks, but that's not really it.
The problem is that when I send a message to the active tab, it (in 99%) is received by the background script of the frame, and not the main page, as I would like.
At first, I thought that this is because the frame script is executed later and it is he who sets his callback. But using broadcastMessage() shows that both handlers are working.