Question about Session variables and Redirects

[Coleen]

Hi All

We have an APSX application using VB.net as the code behind, which uses one
or two session variables per page. These Session variables are passed to
the final page and calculations and summaries are done there. In order for
all of the values to appear on the last page, the user has to view each page
that has a session variable to be passed to the last page. The only way I
can think of to bypass the necessity of the user viewing each page is to do
a redirect if the value that is supposed to be passed is zero. This could
end up in every page needing to be viewed again. Does any one know of a way
to get the session values without redirecting the user to every page? Or,
is there a way to set the last page to run through a redirect for each page
without making them visible, and posting a JavaScript message saying that
the application is running the calculations and the process may take a few
moments? Any suggestions would be greatly appreciated.

TIA

Coleen

 

[Lars Netzel]

I must say I'm not really sure what you mean but you seem to pass variables
to pages and that's not session variable.

Session variables you don't need to pass along thru the pages, you just set
them and then read them.

Session("Page1_Variable1") = "Value"
Session("Page1_Variable2") = "Value"
etc...

Or...

You can set Variables in the Global.aspx page instead that you can access
all the time

Or did I misunderstand you?

/Lars Netzel

 

[Cor Ligthert]

Hi Coleen,

In addition to Lars,

The session variables stays connected to the user (normaly using the cookie)
as long as the session is active.

That can be as long as that is set or as long as that there is no session
abort

All session variables you make on whatever page stay disposable for the
client during that time.

I hope this helps?

Cor

 

[Coleen]

I guess it's difficult to explain without showing how the application works.
Okay, we start with a logon page, this sets a session variable for the
report period that is passed to every page viewed. From there, the user
selects "worksheets" where values from two summary pages are viewed. Those
values are retrieved from the database, but the values from the "worksheets"
need to be passed to the last page - the "Tax Return" (this is not an income
tax return) We pass the values to the tax return from the worksheets using
session variables. The problem is that if the user does not view all of the
worksheets first, the values do not get passed to the tax return. Is there a
way for me to redirect them from the tax return to a specific worksheet, if
the value is missing for that worksheet? I know I can do a
Response.Redirect(), but I may need to do multiple redirects, if they have
missed viewing multiple worksheets...I was just wondering if there is a way
to redirect them with out actually loading the page. Something that would
redirect, but not make the page visible, and post a pop-up message to let
them know the tax return is gathering the information (you know the type
that say "Getting information, this may take a few minutes..."

I hope this clarifies my problem. Any suggestions? TIA

Coleen

 

[Coleen]

That's why we wanted to use the session variable, since it is not kept like
a cookie is. I'm not quite sure what you mean by "All session variables you
make on whatever page stay disposable for the client during that time." ???
We want the session variable to be disposed at the end of their logon
session. The values are saved into the database after everything is
completed, so the session variables can be disposed of each time; but during
the session, we need the variables to do the calculations in the tax return
page (not income tax returns), so we need the variables passed from page to
page to page...to perform calculations. Thanks

Coleen

 

[Cor Ligthert]

Hi Coleen,

My meaning of the word disposable, it shall use next time available.
Therefore I show again my text now with available and some extras.

The session stays available to the user (normally using the cookie) as long
as the session is active.

That can be as long as that is set or as long as that there is no session
abort

All session variables (items) you make, on whatever page, stay available for
the client during that time.

To make it more clear, the cookie works as a kind of key, which tells that
it is always the same user who connects to your server, and it has almost no
information.

All information you can store in the session items, they disappears when the
session aborts.

I hope this clears it something more?

Cor

 

[Coleen]

Yes, it is clear, but it doesn't help (sorry) for my problem - which is how
to get the data from the pages that the users has not actually viewed. In
other words, I can get the session variable with no problem, as long as the
user views the page where the session variable is set...then it is passed
correctly to the tax return. But if the user views the tax return before
viewing the worksheet, the session variable is not set, and therefore is not
available to the tax return. I just want to know if there is a way to do a
redirect back to the page where the session variable is set, without making
the page visible. I need to get those values from each worksheet page to
the tax return. Is that more clear? How do I do a redirect back to the tax
return if I redirect to the worksheet that I need the value from? It's
basically a circle...I need to have each worksheet viewed or redirected to
from the tax return and then I need the tax return to redisplay with the
values from the worksheets. Any suggestion on how to do these redirects?
Thanks
Coleen

 

[Cor Ligthert]

Hi Coleen,

What you asking sounds for me as the old Jewish joke/wisdom which I always
use for this kind of questions where the little Mosh asked to the Rabih
Can God make everything
And the Rabih says yes
And Mosh asks
Can God make a stone which he can himself not raise.
And the Rabih says nothing

However you can do.

If Session.item("MyItem") Is Nothing then
'The session item is not used yet
End if

I hope this helps?

Cor

 

[Lars Netzel]

Just set the Session variables when the user has entered the Value on that
page... on the last page where you need all the info, just check if the
variable has a value or not, or if it even exist (see Cor's Message)

This passing of variables is not nessessary when you work with SESSION
varaibles, they are always accessible... See my fist message in the thread!

You don't need cookies for this, if you dont' want... and besides, here in
sweden there were just a law created that you can't place cookies on users
clients without their permission or them beeing informed about it and what
the Coookies does!

/Lars Netzel

 

[Lars Netzel]

To answer your question and NOT telling you a better solution (which the
rest of the thread is discussing). You can't...

not... without a framesset anyway, if you have a framset you can do it but
it's the first time I have even heared of a solution based on a thing like
that!


For better solution use Cor's Solution with a Nothing check:

If Session.item("MyItem") Is Nothing then
'The session item is not used yet
End if

/Lars

 

[Charlie Smith]

Hi All

We have an APSX application using VB.net as the code behind, which uses one
or two session variables per page. These Session variables are passed to

Coleen.

From your description, it appears that you are not collecting data
from the user on these pages. If that is the case, why not just check
to see which calculations have been missed and call the methods that
perform those in the final page.

HTH,

Charlie

 

[Cor Ligthert]

to

Coleen.

From your description, it appears that you are not collecting data
from the user on these pages. If that is the case, why not just check
to see which calculations have been missed and call the methods that
perform those in the final page.

Hi Charlie,

Intresting can you show me an example how to do that?
I assume you are not talking about session items with the missing
calculations or identificated cache objects.

Cor

 

[Charlie Smith]

Intresting can you show me an example how to do that?

Cor,

If my impression is right about user input requirements not needed
after first form then all the data and logic are already available at
the server and only need to be called in the proper order. Displaying
the pages shouldn't even be necessary.

Of course, if my assumption about user input is wrong, then you
already presented the most direct answer.

If user input is needed, then use logic based upon:

If Session.item("MyItem") Is Nothing then
'Go to appropiate page
End if

to decide which page to go to next.

A string of these if-then statements controlling the exit logic for
each page will create the structure to accomplish the initial goal.

Same could be used in entry of final form (tax return) to decide where
to redirect to and if only one form is incomplete then it would
automagically return to tax return form.

Charlie

 

[Cor Ligthert]

Hi Charlie,

I placed the question to you because often people think that the information
is kept in the class in the same way as with window forms. That is not a
page is stateless, which means that when the page is sended again to the
client, the class goes completly out of scope. Information can only be
stored in:
.. a viewstate wich belongs to the page (sended with the page and returned
with that) however useless for this problem
.. a shared class which belongs to the application, which means available
to all users who visit the application (this information stays until the IIS
server goes down)
.. the cache what is almost the same as a shared class without methods and
events.
.. the session items which ends when the session ends.

I am not sure if I give indirect an answer to your message with this or that
you already knew this, but than this information is maybe usefull for
Coleen.

Cor.

 

[Charlie Smith]

Hi Charlie,

I placed the question to you because often people think that the information
is kept in the class in the same way as with window forms. That is not a
page is stateless, which means that when the page is sended again to the

Cor,

Guilty! I have been working so much with winforms lately that I
wasn't thinking clearly about the charistics of asp.net.

I apologize for any confusion I may have caused. I claim old age as
my excuse

Regards,
Charlie