Session variable in Open Grid Action JS

[gaby_h]

I am trying to set a session variable in the Open Grid Action JS (see pic) so I can use it in the child grid. The problem is the variable gets populated once with a value form row in parent and does not change after that. For expl if I open the child grid the 1st time from parent row#2 and lastname is Rigan, no matter from what row I subsequently reopen the child grid, the value stays the same (Rigan), until I close the parent grid and reopen it. Has anyone used this feature? Any idea why the value is not dynamic?

[nlights]

Re: Session variable in Open Grid Action JS

The problem with session variables is that they often get cached at the browser, and once that happens the browser won't see the refreshed values. See my post http://msgboard.alphasoftware.com/al...-ajax-callback! in this forum for ideas on how to use window[] -variables instead of session variables to carry your data.

[gaby_h]

Re: Session variable in Open Grid Action JS

Thank you very much. Now I understand why it doesn't work the way I want it to work. Thanks again.

[gaby_h]

Re: Session variable in Open Grid Action JS

Pertti:
In your approach you are using an AjacxCB to receive the value from the parent grid and use it in an AjaxCB/Xbasic script in the child grid. In my case I need the value to just exist on the server side in the 2nd grid so I can use it for filtering purposes; I don't need need to execute an AjaxCB/Xbasic script per say. I am struggling to find a way to make it come alive in one of the server side events like OnGridExecute. Any pointer will be highly appreciated.

[nlights]

Re: Session variable in Open Grid Action JS

Gaby --

You need to create a window[] variable in JS, then pass it to your server-side Xbasic via an ajax callback from your server side event(s). window[] variables are nice because they persist and are visible across component calls, and they are not cached at the browser unlike session variables. Server-side local Xbasic variables do not have any persistence beyond the currently executing code, so you can't revisit them from one Xbasic call to another.

You could use server variables to store persistent data for Xbasic, though. It's as easy as this:

DIM server.myvariable as C
server.myvariable = 'Hello!'

This variable will now persist from one Xbasic call to another, and you can read it or modify it just like any other local variable:

?server.myvariable
server.myvariable = 'Goodbye!'

The problem with server variables (if I understand this correctly) is that they are local to the server and available to all sessions running on the server, so another session could come along and change your variables, so this is not ideal either.

I actually thought about creating a "server cookie" database (DBF), which would store session -specific variable/value data and manage itself through timestamps.

So, it would look something like this:

1. Store a variable for another Xbasic call something like this:
StoreServerCookie(session.sessionID, "MyVar", "ABC", "C",2) where "MyVar" is the variable name, "C" is the data type, and 2 is the lifetime of the cookie (in seconds)

2. This function looks for a row in the cookie DBF with the session.sessionID in the session_ID and "MyVar" in the variable_name column.

3. If sessionID/MyVar -combination is found, overwrite its values

3. If sessionID/MyVar -combination is not found, look for expired session cookies for the current sessionID (cookie expires when time elapsed between now and the creation timestamp of the cookie is more than the "lifetime" value - which defaults to 24 hours if not specified)

4. If an expired cookie is found, recycle it with the incoming values

GetServerCookie((session.sessionID, "MyVar") would simply retrieve and return MyVar's value from the cookie database.

This really is a somewhat complex way of getting around the fact that session variables Xbasic variables don't persist, but I don't know of any other way to persist Xbasic values in the server. So I might actually do this one of these days...