class match provides no results

Hi Folks,

i wrote the following iRule Skript which should set HTTP header based on request uri:

when RULE_INIT {
     Enable to debug RedirectByLocation translations via log messages in /var/log/ltm
     (2 = verbose, 1 = essential, 0 = none)
    set static::HeaderByLocationDebug 2
}

when HTTP_REQUEST {

     Create all essential variables for the logic below
     set all variables to an empty value
    set orig_uri [string tolower [HTTP::uri]]

    set static::log_prefix "[IP::client_addr]:[TCP::local_port] URI=$orig_uri:"

     The name of the Data Group (aka class) we are going to use. 
     Parse just the virtual server name by stripping off the folders (if present)
    set class_name "Substitute_[URI::basename [virtual name]]"

    if { $static::HeaderByLocationDebug > 1 } {
        log local0. "$static::log_prefix [IP::client_addr]:[TCP::client_port] -> [IP::local_addr]:[TCP::local_port]"
    }

    set location ""
    set header_name ""
    set header_value ""

     Check whether class_name exist or not.
     If it doesn't exists log an that the data group is missing an exiting
    if {! [class exists $class_name]} {
        log local0. "$log_prefix: Data group $class_name not found, exiting."
        return
    } else {
         Here we know that the needed data group exists and we can go on
        set element [class match -element "$orig_uri" starts_with $class_name]

        if { $static::HeaderByLocationDebug > 1 } {
            if { $element eq "" } {
                log local0. "$static::log_prefix no data group element found."
            } else {
                log local0. "$static::log_prefix data group element found: $element"
            }
        }

         At this point we have a line for the given URI in data group 
         so we can store each entry in the data group line into a local variable
        set location [getfield $element " " 1]
        set header_name [string trimleft [getfield $element " " 2 ] "{" ]
        set header_value [string trimright [getfield $element " " 3 ] "}" ]

        if { $header_name ne "" and $header_value ne "" } {
            if { $static::HeaderByLocationDebug > 1} {
                log local0. "$static::log_prefix HTTP::header insert $header_name $header_value"
            }
            HTTP::header insert $header_name $header_value
        } elseif { $static::HeaderByLocationDebug > 1 } {
            log local0. "$static::log_prefix no header name or value given. Giving up."
        }
    }
}

Now there seem to be a bug and i have no idea.

set element [class match -element "$orig_uri" starts_with $class_name]

Here no element is found.

Maybe one iRule applied also will interfer these iRule. There also ProxyPass is working on URI's.

/foo -> /bla/basel?abcadef (This is Redirected by ProxyPass) /foo -> should fire a header setting. Content-Disposition "attachement; filename=foo.bar"

Data group list looking like this:

{
records {
    /foo {
        data "Content-Disposition \"attachement; filename=foo.bar\""
    }
    /bar {
        data "foo bar"
    }
}
type string

}

Any ideas please?

Cheers

Christian