I have a modal popup in my ASP.NET web appllication that appears after 30 minutes of inactivity. After a further 10 minutes the user is redirected to the login page (and logged out). Witin the popup is a button that the user can press that causes a partial page postback, dismisses the popup, then gives them 30 more minutes before appearing again.
The problem is that on large pages, the postback file size is large. So, I am looking for an ultra-lightweight way to post, say, just a string to the server and retrieve a string, just to keep the user's session active.
It appears that ASMX WebServices, and ScriptMethods/WebMethods provide this mechanism, however:
1. The logic needs to go into a Master Page (as its applicable to every content page in the application)
2. The solution doesn't necessarily require XML
3. The solution shouldn't allow access from external sites/applications, as this only relevant to the current application and serves no purpose externally.
Based on the above, can anyone advice on the best method to use? I will happily award points for all valid contributions.