Socket.IO and Opera 11.64

Question

Opera

Good afternoon!

Through Socket.IO and Redis Pub / Sub, I send real-time notifications to users.

The transports are defined in this order:

io.set('transports', [
        'xhr-polling',
        'jsonp-polling',
        'websocket',
        'flashsocket',
        'htmlfile'
        ]);

Everything works on current versions of browsers (FF21, Chrome 27, Yandex 1.7, Opera 12, IE10).

There is a problem with Opera 11.64

First, it falls into jsonp-polling (why doesn't xhr like it? ..) and immediately on it.
Secondly, a few seconds after the page loads, the “Pop-up window blocked” pops up and disappears almost immediately.

The client page is located at http://example.com/games/main.php, Socket.IO listens to http://example.com:8888

The percentage of users on the 11th Opera is not critical and can be scored, but I want to figure it out at least for myself in order to understand where my legs grow from.

Answer 1

I can assume that Opera only supports CORS since version 12 - developer.mozilla.org/en-US/docs/HTTP/Access_control_CORS
Therefore, Socket.IO is moving to JSONP.