Introduction
Once I started interest in XML/XSL I found that it is impossible to access ASP objects such as Request
inside XSL templates. I tried passing them via XSLTProcessor.addObject
method, it worked for Session
, but couldn't get it working with Request
. Yes, I know you can always pre-define all request variables inside XSL template with xsl:param
and initialize them from ASP code, but say that you don't know exactly what you will be looking for, or there are too many... Not the best approach I guess. My first thought was to append all variables to XML data file as nodes, but this can slow down your web application. Then I came up with this small class that allows you to get any variable when you actually need it.
The idea
Well, the trick is that even XSL cannot access ASP objects, ASP itself sure can. So I'll just create a simple VBScript class with functions which allows retrieving Request
object variables and setting/retrieving Session
variables as well. One you've got the idea you can extend it as you want.
Class ASPObjects
Public Function GetRequestVariable(Key, QType)
Select Case lcase(QType)
Case "querystring"
GetRequestVariable = CStr(Request.QueryString(Key).Item)
Case "form"
GetRequestVariable = CStr(Request.Form(Key).Item)
Case "server"
GetRequestVariable = CStr(Request.ServerVariables(Key).Item)
Case Else
GetRequestVariable = CStr(Request(Key).Item)
End Select
End Function
Public Function GetSessionVariable(Key)
GetSessionVariable = Session(Key)
End Function
Public Function SetSessionVariable(Key, Value)
Session(Key) = Value
SetSessionVariable = ""
End Function
End Class
How to use
Now I'll talk how to use the class above in your XSL/XSLT. After creating XSLProcessor
in your ASP script, just create an instance of ASPObjects
class and add it using method addObject
. Remember to create a namespace in your XSL template (I'm using xasp
below).
...
set xslProc = xslt.CreateProcessor()
set xasp = new ASPObjects
call xslProc.addObject(xasp, "urn:asp-objects")
call xslProc.Transform()
TransformXML = xslProc.output
Set xasp = Nothing
...
Now when we have passed our object to XSL template, let's see how it can be used. First of all add another namespace (urn:asp-objects
here) to your xsl:stylesheet
, then you can access the functions of our object, like in the example below:
<!---->
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:xasp="urn:asp-objects">
<!---->
<xsl:template match="/">
<!---->
<xsl:value-of
select="xasp:GetRequestVariable('hello','querystring')" />
<!---->
<xsl:value-of
select="xasp:SetSessionVariable('username','Me!')" />
</xsl:template>
...
</xsl:stylesheet>
That's all actually. I told you it wasn't that hard :). Now you can extend the class so it will work with Response
object as well or will be able to get cookies along with other Request
parameters or access Server
object methods and properties.