[jamesjyu]

Regarding ajax heavy applications, I have been faced with that particular problem. A few of my sites are javascript heavy apps, with long flows between page reloads. If I ever change my server API in a way that would break the javascript, I need to signal to the client that it needs to refresh. (I keep track of version numbers for the server code, and whenever that is bumped, it means the client is out of sync)

This can be kinda.. awkward. What I've opted either a lightbox or some kind of message saying we need to refresh the page. But that is not ideal.

Has anyone dealt with this issue before? With javascript heavy apps, the development is more like a traditional desktop app, or a mobile app that has to deal with the client/server model interface in a non-trivial manner.

[MartinCron]

I've been doing continuous deployment (multiple production deployments per day) with an ajax-heavy application and have been doing a sort of rolling API change, where both the client and the server still function using the last generation's contract, so I rarely get a client request that the server can't deal with, or send a response that the client can't deal with. It doesn't work with every kind of change, but it has helped me.

Something that you could do (and I may wind up doing) is just having the page ask the server if it needs to refresh itself every so often.

[kylemathews]

I haven't directly but I just happen to be staring at Pivotal Tracker which handles it pretty nicely. The do as you say and push a little lightbox which says "A system change has occurred requiring a refresh of this page. Please click 'OK' to reload Tracker."

[jamesjyu]

And Gmail would have the same problem. But to date, I have never seen Gmail ask to refresh..

[kylemathews]

I think how Gmail handles the problem is they keep multiple instances of the server-side software running, one for each version of the API. From my experience, whenever GMail rolls out a new feature, I don't see it until I do a refresh and frequently that's what GMail tells me I need to do to see the new feature.