Sure. Basically the user is on site A and presses a link that opens a pop up from our site. The pop up logs him in, either through oAuth or a local login. Then site A should get the user details back.
EasyXDM works with iframes, not with popups, so the only option we had (well, the one I thought about) was sending a request to the server every few ms to check if the user logged in. That's pretty horrible. We needed continuous updates from site A to our site so we decided to use socket.io. Sockets don't have sessions, so we listen to a random channel name, and pass that channel name to the popup, which sends the user details as a message to that channel.
That's still complicated. I'm still not sure it's the right approach. And I'm not an expert. But it works for now.
EasyXDM works with iframes, not with popups, so the only option we had (well, the one I thought about) was sending a request to the server every few ms to check if the user logged in. That's pretty horrible. We needed continuous updates from site A to our site so we decided to use socket.io. Sockets don't have sessions, so we listen to a random channel name, and pass that channel name to the popup, which sends the user details as a message to that channel.
That's still complicated. I'm still not sure it's the right approach. And I'm not an expert. But it works for now.