[[ Someone want to write up something about what this [incr tcl] command does? If you think the answer below fulfils the above request please remove it and this text. ---- [AW] from the source code of itcl3.3: * itcl::configbody :: * * Looks for an existing public variable with the name , * and if found, tries to assign the implementation. If has * the form "@name" then it is treated as a reference to a C handling * procedure; otherwise, it is taken as a body of Tcl statements. * As far as I understand it: if you assign a public variable a value with the itcl configure command (myclass configure -myvar Hello) then first the new value is assigned to that variable and afterwards the script in configbody is evaluated additionally. It is also possible to define a config script for a variable when defining the variable: protected variable myvar hello {puts "this is the configscript of myvar"} [GWM] at last it becomes vaguely less fog encrusted. When the program (or user) changes a public variable by use of the 'configure - newvalue' option, then the configbody is called rather like a [trace] or [Itcl trace]. So here is the simplest clear example I can conceive (this is not a competition). console show; update idletasks package require Itcl itcl::class sampleconf { ;# a sample class with a single public variable public variable publicv ;# this var is adjusted using the configure -publicv... constructor {} { } method setpublicv {dn} { set publicv "$dn" } } # create a sample instance of the class: set btn [sampleconf h2] # add a configbody for publicv itcl::configbody sampleconf::publicv {tk_messageBox -message "Publicv in $this was set to $publicv by a configure command."} h2 configure -publicv "A new Value" # change the publicv by configure and you see a message box. h2 configure -publicv "The same old Value" h2 setpublicv "A value which is not sent via the configbody" # change the publicv again by configure and again you see a message box. h2 configure -publicv "Another Value" Note that the configbody applies to all instances of sampleconf, but that changing the value of publicv (by calling method setpublicv) does NOT call the configbody. ---- [Category Command] a part of the [incr tcl] object oriented package