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Forum Discussion

Deb_Allen_18's avatar
Deb_Allen_18
Historic F5 Account
Feb 22, 2006

Referencing a class with a variable

I'm wondering if I can reference a class with a variable?

 

 

Will the class reference below evaluate to $::myclass?

 

 

when HTTP_REQUEST {

 

set uri_discards myclass

 

if {[matchclass [HTTP::uri] starts_with $::{$uri_discards}]}{

 

discard

 

}

 

}

 

 

I also noticed that I don't get any errors loading up this rule, even though neither class "myclass" nor "uri_discards" exists, so I'm wondering how much classname verification I might need to perform using variables in this manner?

 

 

thanks

 

/deb

 

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4 Replies

  • Colin_Walker_12's avatar
    Colin_Walker_12
    Historic F5 Account
    Feb 22, 2006
    There's actually a tech tip about dynamically declaring class names here: Click here

     

     

    Check it out and let us know if you've got any further questions.

     

     

    Thanks,

     

    -Colin
  • Deb_Allen_18's avatar
    Deb_Allen_18
    Historic F5 Account
    Feb 23, 2006
    sweet, thanks!

     

     

    so using eval against the findclass command results validates the cookie value for its intended use - finding the related pool or branching elsewhere if not found:

     

     

    I take it there's no graceful way to do it without setting the 2 variables?
  • JCohen's avatar
    JCohen
    Ret. Employee
    Oct 31, 2008
    Colin,

     

     

    The link in this post is broken? Getting access denied viewing tab. Does this article still exist? Is it still relevant?

     

     

    Jason
  • hoolio's avatar
    hoolio
    Icon for Cirrostratus rankCirrostratus
    Nov 03, 2008
    Hi Jason,

     

     

    This is the article Colin was referring to:

     

     

    Dynamically declaring a class name based on Request info

     

    http://devcentral.f5.com/Default.aspx?tabid=63&articleType=ArticleView&articleId=37

     

     

    I think you might be able to use subst as well:

     

     

    TCL subst man page

     

    http://www.tcl.tk/man/tcl8.4/TclCmd/subst.htm

     

     

    Examples:

     

    http://devcentral.f5.com/Default.aspx?tabid=53&view=topic&postid=23503&ptarget=23562

     

     

    Aaron