The purpose of this page is to illustrate the use of the msgcat package to make a Tk software internationalized automatically. The recommended usage of the msgcat package to translate messages is to insert msgcat::mc instructions like this (http://wiki.tcl.tk/1488 ):
Instead of
label .x -text Files
you write
label .x -text [msgcat::mc Files]
This is good, but forces the developper to insert "msgcat::mc" everywhere into the current Tcl script. Of course, it is well known that the Frink tool can instrument a Tcl script and insert the msgcat::mc automatically. But the resulting script is modified, which may be unwanted (http://wiki.tcl.tk/2611 ).
What should be available is a method to translate automatically the software, """without modification""" of the original script. The only things which should be done is :
- create the "yourlanguage.msg" catalog, - use msgcat and configure it with the desired language.
One can try to overload the Tk widgets to use the msgcat::mc automatically. The following is an example. The first call to "tk_chooseDirectory" is untranslated. Then one creates a translation command inside the "mynamespace" namespace. Then the tk_chooseDirectory is overloaded so that the next use of "tk_chooseDirectory" automatically uses the msgcat::mc command with the provided translation command.
package require Tcl
package require Tk
package require msgcat
::msgcat::mclocale fr
set dirname [tk_chooseDirectory -title "This is an untranslated title"]
msgcat::mcset fr "This is an untranslated title" "C'est mon titre"
namespace eval mynamespace {
proc translate { original } {
set translated [msgcat::mc $original]
return $translated
}
}
if {[info commands "::tk_chooseDirectory"]=="::tk_chooseDirectory"} then {
rename ::tk_chooseDirectory ::_tk_chooseDirectory
proc ::tk_chooseDirectory {args} {
set command [list "::_tk_chooseDirectory"]
foreach {key value} $args {
if {$key=="-title" || $key=="-message"} then {
set value [mynamespace::translate $value]
}
lappend command $key $value
}
set answer [eval $command]
return $answer
}
}
set dirname [tk_chooseDirectory -title "This is an untranslated title"]
See also:
Tcl syntax help - Arts and crafts of Tcl-Tk programming
Category Command - Category Local - Category String Processing