How do you call a method from a variable in ASP Classic?

Question

For example, how can I run me.test below?

myvar = 'test'
me.myvar

ASP looks for the method "myvar" and doesn't find it. In PHP I could simply say $me->$myvar but ASP's syntax doesn't distinguish between variables and methods. Suggestions?

Closely related to this, is there a method_exists function in ASP Classic?

Thanks in advance!

EDIT: I'm writing a validation class and would like to call a list of methods via a pipe delimited string.

So for example, to validate a name field, I'd call:

validate("required|min_length(3)|max_length(100)|alphanumeric")

I like the idea of having a single line that shows all the ways a given field is being validated. And each pipe delimited section of the string is the name of a method.

If you have suggestions for a better setup, I'm all ears!

Answer 1

You can achieve this in VBScript by using the GetRef function:-

Function Test(val)
  Test = val & " has been tested"
End Function

Dim myvar : myvar = "Test"
Dim x : Set x = GetRef(myvar)
Response.Write x("Thing")

Will send "Thing has been tested" to the client.

So here is your validate requirement using GetRef:-

validate("Hello World", "min_length(3)|max_length(10)|alphanumeric")


Function required(val)
    required = val <> Empty
End Function


Function min_length(val, params)
    min_length = Len(val) >= CInt(params(0))
End Function


Function max_length(val, params)
    max_length = Len(val) <= CInt(params(0))
End Function


Function alphanumeric(val)
    Dim rgx : Set rgx = New RegExp
    rgx.Pattern = "^[A-Za-z0-9]+$"
    alphanumeric = rgx.Test(val)
End Function


Function validate(val, criterion)

    Dim arrCriterion : arrCriterion = Split(criterion, "|")
    Dim criteria

    validate = True

    For Each criteria in arrCriterion

        Dim paramListPos : paramListPos = InStr(criteria, "(")

        If paramListPos = 0 Then
            validate = GetRef(criteria)(val)
        Else
            Dim paramList
            paramList = Split(Mid(criteria, paramListPos + 1, Len(criteria) - paramListPos - 1), ",")
            criteria = Left(criteria, paramListPos - 1)
            validate = GetRef(criteria)(val, paramList)
        End If
        If Not validate Then Exit For
    Next

End Function

Having provided this I have to say though that if you are familiar with PHP then JScript would be a better choice on the server. In Javascript you can call a method like this:-

function test(val) { return val + " has been tested"; )
var myvar = "test"
Response.Write(this[myvar]("Thing"))