session var cached on web page problem

[Peter.Greulich]

I have a grid on an a5w page. The grid dynamically sets a session var by Ajax callback. Works great the first time. But on subsequent times it doesn't update the session var. It's cached. If I refresh the browser page and then do the callback all is well. So how do I get the session var to update each time on the Ajax callback w/o manually refreshing the page?

[Davidk]

Re: session var cached on weg page problem

In what event are you setting the var?

function OnGridExecute as v (e as p)
'This event fires every time the Grid is run, including every Ajax callback.

function OnGridInitialize as v (e as p)
'This event fires when the Grid is initialized. It also fires when the Grid is
're-initialized after a session has expired.
'IMPORTANT: The onGridExecute event, which fires every time the Grid is executed fires BEFORE this event.

[Peter.Greulich]

Re: session var cached on weg page problem

David, from a button.

[Steve Workings]

Re: session var cached on weg page problem

Peter -

Do I read this that you have one event on the grid, and another on a button to set the variable?

Can you show us the line of code you're using to make the assignment(s)? I presume your button's code is in the Xbasic Functions section for the callback?

[Davidk]

Re: session var cached on weg page problem

So, the button is doing an Ajax Callback that is setting a session var? Then the var should be set each time that button is pressed. In Working Preview mode, does the code get executed each time?

[Peter.Greulich]

Re: session var cached on weg page problem

So, the button is doing an Ajax Callback that is setting a session var? Then the var should be set each time that button is pressed. In Working Preview mode, does the code get executed each time?

Yes, it updates in W.P. I use the session var which is passed into an argument in 2nd grid as a filter. Grid 1 the user enters in part#, clicks the button and opens grid2 which is filtered on part. Works 1st time fine. Close grid 2, enter a new part, click button, grid2 opens w. prev part#, not the last entered. But if I hit F5 in the browser first, then enter a new part, grid2 opens w. correct filter.

[mumfie]

Re: session var cached on weg page problem

we had an issue with a couple of grids in v11 where we were setting session variables in grid events using format e.rv.Session.myVar ="test"
we changed the code to use Session.myVar="test" and it seemed to resolve the problem.
another thing you could try is to output the session value to a file or a5w_info() page after the second update to see if the session variable has the expected value.

[Davidk]

Re: session var cached on weg page problem

I see the same behaviour but the 2nd Grid doesn't filter properly on the first opening, only subsequent refreshes. There are so many ways to set up this scenario and I'm not sure how you're opening grids etc., but since you're entering or selecting a Part # from a grid then I'll assume that Part # is a field in that grid. Grid 2 is filtered on that Part #. I don't know if you can use Action Javascript to Open a Grid Component, but it works. That particular dialog allows the entry of a filter - and this works every time.

It seems that the session var is a timing issue.

If you're using Action Javascript, then there's a setting to turn off using a cached grid. That solves part of my problem. The grid now opens the first time with the correct filter, but closing and opening again I am one variable behind. I don't have to refresh or go back to design, but the var is not updated right away.

[joannristau]

Re: session var cached on weg page problem

Although this is not exactly the same issue, but telling the browser to never cache the page helped on one of my dillemas.

I had a problem with a page running some xbasic working fine the first time the page was called from a button on a grid but subsequent calls from the button didn't execute the script - just displayed the page. The cached page was not executing the a5 xbasic and added this code to the head section on the page

<META HTTP-EQUIV="PRAGMA" CONTENT="NO-CACHE">

Seemed to fix the problem for my page.

[RichCPT]

Re: session var cached on weg page problem

Try the technique in video # 69 for passing data. I think you will find it works much better than relying on session variables.

http://www.ajaxvideotutorials.com/V1...dToAnother.swf

[Peter.Greulich]

Re: session var cached on weg page problem

<META HTTP-EQUIV="Pragma" CONTENT="no-cache">

Thanks for the reminder. Haven't tried Pragma-no-cache in a while. Does seem to do the trick.

[nlights]

Re: session var cached on web page problem

I have hit the same wall. Big time. Session variables do seem to stick around, probably cached META tag in header didn't help either. Only refreshing the browser will refresh the session variables. Grrrrrrr.... So, [window] -approach it is (too bad since I followed Selwyn's video M41 to the tee and got excited about this cool bean until it turned out that caching kills it.) Grrrrrr..... Is there really no way to clear session variables between calls?

[nlights]

Re: session var cached on web page problem

Still having a problem... Using the approach explained in http://www.ajaxvideotutorials.com/V1...dToAnother.swf, I can see that the window[var] is refreshed properly with each click of the parent form button. I can grab the value in the child grid with javascript. However, I also need to use that value in my xBasic code that does some filtering on the child grid, but I have no idea how to get to it with xBasic. I've wikid and googled and manualed for this, the cows have come home and gone out again, but still no answer... I assume there must be an xBasic function that can deal with the browser window object the same way as javascript does. Any ideas?

[Peter.Greulich]

Re: session var cached on web page problem

Yeah, it seems to depend upon the browser etc. I ended up using a filter passed to the a5w page. There are some links that might help you w. the session JS thing.

But have you looked at these JS methods?

{grid.Object}.gridBaseFilterSet(filterExpression, orderExpression, filterParameters)
{grid.Object}.gridFilterSet(filterExpression [, orderExpression [, filterParameters]])

[nlights]

Re: session var cached on web page problem

That would certainly work for filtering, thanks!

My problem is a little different, however:

I call a child grid from a parent grid.
I pass a primary key from the parent grid to the child grid (again, session vars are unreliable when it comes to refreshing, so I use window -object to attach the PK to it and keep it around
I open the child grid, and when I click a button below the grid, I want the foreign key in the child grid's table to be populated with the PK coming from the parent grid

I've tried your hidden column technique to write the incoming PK into a calculated column on the child grid, but I must be doing something wrong because I can't get to that value with xBasic.

Here's (part of) my inGridRender JS:

// Establish event ID and event name variables

var x_wvE_EVENTID = '';
var x_wvE_NAME = '';

// Assign window[] variables passed from the parent grid to the child grid

if(window['wvE_EVENTID']) x_wvE_EVENTID = window['wvE_EVENTID'];
else x_wvE_EVENTID = '-999';

//write the Event ID value to a hidden calculated column in the grid

{grid.Object}.setValue('G','GET_JS_VAR',rowNum,x_wvE_EVENTID);

Next up: click button below the grid. What should happen now is that the data behind the grid is refreshed with the ID (foreign key value from the parent to the grid data)

So I tried this in the button's OnClick event (xBasic):

vEventID = e._currentRowDataNew.GET_JS_VAR

However, e._currentRowDataNew is empty for some odd reason (as is e._currentRowDataOld) so my xBasic code can't get to the value I inserted in the grid.

This is a tough nut (for me, that is) and I'd sure like to move beyond it by now, 28 hours later...