I need suggestion if it is possible to read session variable from wordpress or joomla, to check if a user is logged and then display wisej in a iframe.
or I must read database?
I don’t think it’s possible to access a .NET instance from php. There is a php com bridge, but it may not be the easiest way.
Another problem is to identify the session from php. Wisej stores the session id in a cookie named “Wisej.SessionId” but if it’s in an iframe then the cookie is only visible to the iframe. Maybe the parent page can read it, unless the origin is different. Wisej can also store the session in the URL, when using cookieless: true.
The best way is probably to save shared data on a local file or database using an id (user id?) that is understood by both environments.
I think your best way to achieve that with WP is to read/share some cookies between WP (or Joomla) and your Wisej app
to verify that a user is authenticated. If you browse around searching for WP | Joomla with ASP.NET (which should roughly be the same scenario)
you can find a couple of pointers, too.
Hope that helps.