Viewing the contents of Previous Page using ASP

979

Expert 512MB

Hi Vini171285,

Using session variables to retain the values of your controls is a valid and well accepted method. Some people would argue that it would be better to pass the values as hidden fields through a form or the querystring but as long as it works for you I think it's fine.

Can you print the code you're trying to use to set the value of your listbox with a session variable. There's no reason why it shouldn't work so it's probably just a little bug.

Dr B

Apr 22 '08 #2

Hi, DrBunchman

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Global.asa

<script language=vbscript runat=server>

Sub Session_onStart()

    Session("name")=""

    Session("pwd")=""

    Session("age")=""

End Sub
 
Sub Session_onEnd

    Session("name")=""

    Session("pwd")=""

    Session("age")=""

End Sub

</script>
 
z1.asp

<HTML>

<BODY>

<form method=post action="z2.asp">

Name:<input type=text name=name value=<%=Session("name")%>><BR>

Password:<input type=password name=pwd >

<BR>

Age:<select name=age>

        <option value=1>1 to 10

        <option value=10>11 to 20

        <option value=20>21 to 30

    </select>

<input type=submit>

</form>

</BODY>

</HTML>
 
z2.asp

<%@ language=VBScript%>

<% option explicit%>

<html>

<body>

<%

Session("name")=Request.Form("name")

Session("pwd")=Request.Form("pwd")

Session("age")=Request.Form("age")

Session.TimeOut=1

Response.Redirect "z3.asp"

%>

</body>

</html>
 
z3.asp

<html>

<body>

<form method=post action="z1.asp">

Hello<BR>

<BR>

<a href="z1.asp">back</a>

<input type=submit>

</form>

</body>

</html>

This is my code.Its just an example..
actual code is very big,in which we are retrieving data from database for listboxes..
and in our project there are 4 pages containing near about 86-87 listboxes..
So ,is Session still appropriate??

Everything is working properly with text box..
but in the case of list box,instead of printing the selected content, listbox is loaded as it is,and the selected value is lost..
What can be done in this situation??

Thanx

Apr 22 '08 #3

979

Expert 512MB

As I have said the question of whether you should use session variables in this situation is one that divides opinion. There is an article here that outlines some of the pros & cons of using them and I think you'll have to make up your own mind based on your circumstances.

To get your list box to maintain it's state you can use the following example:

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  <select name=age> 

<option value=1 <% If Session("age") = 1 Then Response.Write(" selected ") End If %>>1 to 10</option>

<option value=10 <% If Session("age") = 10 Then Response.Write(" selected ") End If %>>11 to 20</option>

<option value=20<% If Session("age") = 20 Then Response.Write(" selected ") End If %> >21 to 30</option>

</select>

Let me know how you get on.

Hope this helps,

Dr B

Apr 22 '08 #4

432

Expert 256MB

Hi..

I want to view the contents of previous page,but when i move from second page to first page,it is reloaded and the selected contents are lost..
So what should i do so that when i move from 2nd page to 1st page,all selected contents should remain same..
Actually i tried using session and it is working,but it doesn't work with listboxes.
Is it a good practice to use Session variables.

Thanx

Session variables was going to be my answer for you. Yes session variables are good practice as long as you clear them when you are done with them.

What do you mean by the session variable doesnt work with the listbox? If you are allowing multiple selections of the list box you need to set up an array variable to handle that probably to hold all the users selections.

Otherwise the only way to pass data is to use the querystring which if you have alot of it can get very tedius. (myaddress.asp?data1=this&data2=this). Or you can use hidden text box fields and get the data with request.form on the next page, etc.

Apr 22 '08 #5

hi..
This is my code when trying to fill list box from database..
Error is in IF stmt(Type mismatch)..
Can u Help..
Code:

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  <%@ language=VBScript%> 

<% option explicit %>

<!--#include virtual="/adovbs.inc"-->

<HTML>

<BODY>

<form method=post action="z2.asp">

Name:<input type=text name=name value=<%=Session("name")%>><BR>

Password:<input type=password name=pwd >

<BR>

Age:<select name=age>

<%

    Dim objConn

    Set objConn=Server.CreateObject("ADODB.Connection")

    objConn.ConnectionString="DSN=Info.dsn;uid=vini;pwd=vini"

    objConn.Open
 
    Dim sql

    sql="SELECT * FROM age"
 
    Dim objRS

    Set objRS=Server.CreateObject("ADODB.Recordset")

    objRS.Open sql,objConn
 
    Do while not objRS.EOF

        Response.Write "<option value='" & objRS("num") & "'"

        If Session("age")=objRS("num") Then

            Response.Write "selected"

        End If

        Response.Write ">"

        Response.Write objRS("age")

        objRS.MoveNext

    Loop
 
    objRS.Close

    Set objRS=Nothing
 
    objConn.Close

    Set objConn=Nothing

%>

</select>
 
<input type=submit>

</form>

</BODY>

</HTML>

Apr 23 '08 #6

979

Expert 512MB

You could try using

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If Session("age") = CInt(objRS("num"))

to cast your record item to a type of integer while comparing it.

Any good?

Dr B

Apr 23 '08 #7

Hi..
Its not working
any other suggestion..

Apr 23 '08 #8

979

Expert 512MB

Hmm....

What about if you do something like:

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  Dim num 

num = objRS("num")
 
If Session("age") = num Then

Dr B

Apr 23 '08 #9

432

Expert 256MB

Hi..
Its not working
any other suggestion..

When you say its not working does that mean you are still getting the type mismatch error or something else? Also which line are you getting that error on?

Since I don't know whats in your database I am going to assume one of the problems may be checking for null?

As far as casting the data type the only time that matters in asp is when your sending the value to a database or a vb class. All variables in asp are automatically variants.

Lastly another thing I noticed was that when you cancatonate (like below) you are using the single quotes. That is for SQL, not for strings. So I removed them for this example. That could be your problem also.

One more thing too and maybe I'm just missing something here...but you dont have the <select> tag before you start writing your <option>?
Oh yeah...a close option tag you were missing too </option> at the end

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    'need <select> tag??
 
    Do while not objRS.EOF

         If Not IsNull(ObjRS("num")) then

             Response.Write "<option value=" & objRS("num") & ""

             If Session("age")=objRS("num") Then

                 Response.Write " selected" 'added a space to seperate

             End If

        else

             Response.Write "<option value=0"

        end if
 
        Response.Write ">" 

        Response.Write objRS("age")

       'then you need a close tag here

       response.write "</option>"

        objRS.MoveNext

    Loop

    'need an </select> tag??

Apr 23 '08 #10

432

Expert 256MB

OK I see your <select> tags now, but you are missing the </option>.
Sorry

Apr 23 '08 #11

Hmm....

What about if you do something like:

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Dim num

num = objRS("num")

If Session("age") = num Then

Dr B

We have tried this also,but its still not working...Its not giving any error,but selected value is lost,list box regains its default value as it is....

Apr 24 '08 #12

This is changed code,but it has the same problem of not retaining values between pages...
It is giving no error....

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Code:

<%@ language=VBScript%>

<% option explicit %>

<!--#include virtual="/adovbs.inc"-->

<HTML>

<BODY>

<form method=post action="z2.asp">

Name:<input type=text name=name value=<%=Session("name")%>><BR>

Password:<input type=password name=pwd>

<BR>

Age:<select name=age>

<%

    Dim objConn

    Set objConn=Server.CreateObject("ADODB.Connection")

    objConn.ConnectionString="DSN=Info.dsn;uid=vini;pwd=vini"

    objConn.Open
 
    Dim sql

    sql="SELECT * FROM age"
 
    Dim objRS

    Set objRS=Server.CreateObject("ADODB.Recordset")

    objRS.Open sql,objConn
 
    Do while not objRS.EOF

        If Session("age")=CInt(objRS("num")) Then

            Response.Write "<option value='" & objRS("num") & "' selected>"

        Else

            Response.Write "<option value='" & objRS("num") & "'>"

        End If

        Response.Write objRS("age") & "</option>"

        objRS.MoveNext

    Loop
 
    objRS.Close

    Set objRS=Nothing
 
    objConn.Close

    Set objConn=Nothing

%>

</select>
 
<input type=submit>

</form>

</BODY>

</HTML>

Apr 24 '08 #13

432

Expert 256MB

You are still not cancatonating correctly in your strings.

You don't use single quotes for strings, only SQL.

WRONG:

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Do while not objRS.EOF

If Session("age")=CInt(objRS("num")) Then

Response.Write "<option value='" & objRS("num") & "' selected>"

Else

Response.Write "<option value='" & objRS("num") & "'>"

End If

Response.Write objRS("age") & "</option>"

objRS.MoveNext

Loop

RIGHT:

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Do while not objRS.EOF

If Session("age")=CInt(objRS("num")) Then

Response.Write "<option value=" & objRS("num") & " selected>"

Else

Response.Write "<option value=" & objRS("num") & ">"

End If

Response.Write objRS("age") & "</option>"

objRS.MoveNext

Loop

As far as retaining your values, there is no reason that Session("var") should not work.

Try bringing stuff back to basics to find out why your losing the value. Do some response.write's on your session variables for testing. I would recommend doing a response.write on your Session("age") before your IF statement so you can see whats in there.

If possible just start from scratch for testing purposes just to work with some session variables.

Or do a step through if you have MS Studio and a localhost) and try to determine at what point the value is being lost.

Don't forget if you need to you can also work with hidden text fields and simply get the value with request.form.

Apr 24 '08 #14

979

Expert 512MB

You are still not cancatonating correctly in your strings.

You don't use single quotes for strings, only SQL.

There's nothing wrong with using single quotes inside a string to delimit your property values.

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Response.Write "<img src='foo.gif' alt='bar' />"

generates perfectly good mark up and as far as I know this would never generate an error.

Unless there's a reason you think otherwise and I'm completely wrong ;-)

Dr B

Apr 24 '08 #15

Hi Jeffstl and DrBunchman,

Jeffstl, as u said presence & absence of Single quotes made no difference...
Dr. Bunchman the solution tat u provided us the last time worked...but as it was a harcoded 1...& v want to retrieve large values from database...this code was not sufficient:::

Code

Expand|Select|Wrap|Line Numbers

  
<%@ language=VBScript%>

<% option explicit %>

<!--#include virtual="/adovbs.inc"-->

<HTML>

<BODY>

<form method=post action="z2.asp">

Name:<input type=text name=name value=<%=Session("name")%>><BR>

Password:<input type=password name=pwd>

<BR>

<%

Response.Write CInt(Session("age"))

%><BR>

Age:<select name=age>

<%

    Dim objConn

    Set objConn=Server.CreateObject("ADODB.Connection")

    objConn.ConnectionString="DSN=Info.dsn;uid=vini;pwd=vini"

    objConn.Open
 
    Dim sql

    sql="SELECT * FROM age"
 
    Dim objRS

    Set objRS=Server.CreateObject("ADODB.Recordset")

    objRS.Open sql,objConn
 
    Do while not objRS.EOF

        If Session("age")=CInt(objRS("num")) Then

            Response.Write "<option value=" & objRS("num")& " selected>"

            Response.Write objRS("age") & "</option>"

        Else

            Response.Write "<option value=" & objRS("num") & ">"

            Response.Write objRS("age") & "</option>"

        End If

        objRS.MoveNext

    Loop
 
    objRS.Close

    Set objRS=Nothing
 
    objConn.Close

    Set objConn=Nothing

%>

</select>
 
<input type=submit>

</form>

</BODY>

</HTML>

I think der is some mistake in writng <option> part...
The session variable actually contains the correct value...but is not displayed...
If v use the back button of the web page..the correct value tat v have selected is displayed...but if v use submit button & go back...the selected value is lost...even though session variable contains correct value...
maybe some problem with button click !!

Thanx !!

Apr 25 '08 #16

979

Expert 512MB

Hi Vini171285,

Firstly, please remember to use the # button when writing a post to surround your code with code tags as it feels like I've had to edit every sinlge one of your posts in this thread! It makes things much easier to read and helps me out because I don't have to add them in myself!! Thanks :-)

Back to your bug: there's something weird going on here....I tested your code and got the same problem but I can't see where it is. I'm sorry I haven't got more time to look at this right now but hopefully Jeff will be able to or I'll take a look over the weekend.

Regards,

Dr B

Apr 25 '08 #17

979

Expert 512MB

Just a quick question: your condition is

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If Session("age") = objRS("num")

It shouldn't be

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If Session("age") = objRS("age")

should it?

Dr B

Apr 25 '08 #18

omerbutt

638

512MB

Just a quick question: your condition is

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If Session("age") = objRS("num")

It shouldn't be

Expand|Select|Wrap|Line Numbers

If Session("age") = objRS("age")

should it?

Dr B

would it make any difference by not putting the ; sign in your select query

Apr 26 '08 #19