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**Pat Bremkamp** · 07-16-2008, 06:55 PM

Re: Select Grid Row, Set session variable

Steve,

Screen1 shows the setup to create the session variable. Set one field to be a link and define it as shown. It ususally works best to use a calculated field for the link rather than the field itself. So you have the field Order_id and set the link on calcOrder_id defined as =Order_Id.

Then, use the session as a filter. If the target is a grid, then define an argument based on the session variable and set a filter based on some variable equal to that session variable. See screen2 and screen3.

Pat

**Steve Workings** · 07-16-2008, 09:29 PM

Re: Select Grid Row, Set session variable

Thanks Pat. I know the stuff you show here. But I don't want a link that redirects the page - I don't want a "target."

All I want to do is have the user click something to select a row, and have that click set the session variable.

**drgarytraub** · 07-16-2008, 10:14 PM

Re: Select Grid Row, Set session variable

Steve,

Unless I am missing your point, it seems to me that what you want to do is pretty close to waht Pat said.

Simply define a calculated field called say "var" - link this to a dummy page that does nothing, but you can then define session variable(s) either in the page or in the link from the grid to the page.

Gary

**Steve Workings** · 07-16-2008, 10:56 PM

Re: Select Grid Row, Set session variable

Any link you do that way makes an href, which takes you to another page.

I don't want to move off the current page - just and only set a session variable.

Each row of data in the grid has an order_id.

I have a set of buttons outside the grid to do things but I need first to select the session variable of the row the user wishes to act upon.

**drgarytraub** · 07-16-2008, 11:35 PM

Re: Select Grid Row, Set session variable

Steve,

You may come up with a more direct method, but the following does work:

Do as I described above, i.e., link to a dummy page, define the session variable within the Link Address Builder.

Then, create a dummy page that has nothing in it except the following:

<html>
<head>
<meta name="generator" content="Alpha Five HTML Editor Version 9 Build 1479-3182">
<title></title>

<script language="JavaScript" type="text/javascript">
javascript:window.history.go(-1);
</script>

</head>

<body>

</body>

</html>

This will create the session variable with the idnumber of the row you are on, and the dummy page's java script will return you right back to the grid.

Gary

**Pat Bremkamp** · 07-17-2008, 12:41 AM

Re: Select Grid Row, Set session variable

Actually, you don't need another page. Just call the same page in the link, it will be perfectly happy to call itself.

Pat

**drgarytraub** · 07-17-2008, 12:43 AM

Re: Select Grid Row, Set session variable

Yes, that works too :D

**drgarytraub** · 07-17-2008, 12:45 AM

Re: Select Grid Row, Set session variable

On second thought, I think it is a bit quicker to use the separate page with the java script because the page with the grid does not have to reload.

**Steve Wood** · 07-17-2008, 12:49 AM

Re: Select Grid Row, Set session variable

Since a session variable exists on the server, how could you create a session variable with out making a round trip to the server (AJAX or otherwise)? Secondarily, how would the session variable be of any use to you if it was suddenly magically set on an untouched/unrefreshed page? The only time it is going to be of any use is when you move to another page where it can be 'deployed' in some manner. (I'm sure you have an answer, I just can't figure it out.) AJAX is the way to go and would create the least amount of visual screen refresh, but I don't know how you would do it. (Apparenly not paying attention during your class on the subject.)

Gary's solution is the same as creating a code-only page with:

session.myvar=id
response.redirect(request.referer)
where id comes in the URL or POST.

**drgarytraub** · 07-17-2008, 06:21 AM

Re: Select Grid Row, Set session variable

Steve,

That explanation was useful for me to hear. It reminds of the difference between server and client side issues.

Thus, if I read you right, the only way Steve (Workings) can do what he wants is to make some call to the server - he cannot do what he wants "without leaving the page." Which also means that my second method, using java script, would not work, because all that does is goes back one page in the cache.

So, Pat's suggestion of redirecting to the same page is probably the fastest (other than AJAX).But if the page is relatively small, AJAX probably would not be needed. Otherwise, if there are a lot of fields on the page for example, then AJAX would likely make a big difference.

**JerryBrightbill** · 07-17-2008, 07:40 AM

Re: Select Grid Row, Set session variable

Setting a session variable on the server using AJAX is a very trivial operation using a custom control and a AJAX callback. You need a very simple callback page and a simple onclick event on a button in the control.

First create the callback page. In this example, the session var name can be set dynamically by sending the name to use and the value to populate as variables in the call back. The call back sends 2 values, 'var', which is the name of the session variable, and 'varvalue', which is the character value to place in the session variable. If the session variable isn't character, you would need to send a data type variable value as well. Something like 'vartype=T' would work to tell the callback to convert the type to the 'T' type, which is time. This is all you need on the page.

Code:

<%a5 
dim var as c
dim varvalue as c
if var <> ""
	eval("session."+var) = varvalue
end if
%>

In this example (which doesn't include any code for setting type), that was saved on a page named 'setvar.ajax.a5w'. On the grid, create a custom control that uses an AJAX callback on the 'onclick' for the field that is the source. In this example, the source is the 'customer_id' field. The control can be any control that has an 'onclick' event.

Code:

Customer_id_render = "<input name=\"setvar\" type=\"button\" value=\"Set Session\" onclick=\"a5_AJAX_Callback('setvar.ajax.a5w','var=custid&varvalue="+Data.Customer_id+"')\"/>"

Of course, the JavaScript files needed for the AJAX must be added to any page that has this grid. They can be added in the page header just after the <title></title>

HTML Code:

<script type="text/javascript" src="javascript/core.js"></script>
<script type="text/javascript" src="javascript/aui.js"></script>
<script type="text/javascript" src="javascript/AjaxFormLibrary.js"></script>

Publish both pages. When the page with the grid is run, clicking the button will set the session var 'session.custid' on the server with a value that matches the 'customer_id' in the row that had the button. The value at this point only exists on the server. You could send the value back to the original grid and populate a control, but if the session var is used for any purpose in this grid such as filtering, the whole page must be refreshed by making a request back to the server. If that is the case, using AJAX is unnecessary.

**Steve Workings** · 07-17-2008, 09:14 AM

Re: Select Grid Row, Set session variable

Thanks Jerry, that's exactly what I needed.

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Select Grid Row, Set session variable

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