msgcat.tcl   [plain text]

# msgcat.tcl --
#
#	This file defines various procedures which implement a
#	message catalog facility for Tcl programs.  It should be
#	loaded with the command "package require msgcat".
#
# Copyright (c) 1998-2000 by Ajuba Solutions.
# Copyright (c) 1998 by Mark Harrison.
#
# See the file "license.terms" for information on usage and redistribution
# of this file, and for a DISCLAIMER OF ALL WARRANTIES.
# 
# RCS: @(#) msgcat.tcl,v 1.3 2003/01/21 19:40:09 hunt Exp

package require Tcl 8.2
# When the version number changes, be sure to update the pkgIndex.tcl file,
# and the installation directory in the Makefiles.
package provide msgcat 1.3

namespace eval msgcat {
    namespace export mc mcload mclocale mcmax mcmset mcpreferences mcset \
	    mcunknown

    # Records the current locale as passed to mclocale
    variable Locale ""

    # Records the list of locales to search
    variable Loclist {}

    # Records the mapping between source strings and translated strings.  The
    # array key is of the form "<locale>,<namespace>,<src>" and the value is
    # the translated string.
    array set Msgs {}

    # Map of language codes used in Windows registry to those of ISO-639
    array set WinRegToISO639 {
        01 ar 0401 ar_SA 0801 ar_IQ 0c01 ar_EG 1001 ar_LY 1401 ar_DZ
              1801 ar_MA 1c01 ar_TN 2001 ar_OM 2401 ar_YE 2801 ar_SY
              2c01 ar_JO 3001 ar_LB 3401 ar_KW 3801 ar_AE 3c01 ar_BH
              4001 ar_QA
        02 bg 0402 bg_BG
        03 ca 0403 ca_ES
        04 zh 0404 zh_TW 0804 zh_CN 0c04 zh_HK 1004 zh_SG 1404 zh_MO
        05 cs 0405 cs_CZ
        06 da 0406 da_DK
        07 de 0407 de_DE 0807 de_CH 0c07 de_AT 1007 de_LU 1407 de_LI
        08 el 0408 el_GR
        09 en 0409 en_US 0809 en_GB 0c09 en_AU 1009 en_CA 1409 en_NZ
              1809 en_IE 1c09 en_ZA 2009 en_JM 2409 en_GD 2809 en_BZ
              2c09 en_TT 3009 en_ZW 3409 en_PH
        0a es 040a es_ES 080a es_MX 0c0a es_ES@modern 100a es_GT 140a es_CR
              180a es_PA 1c0a es_DO 200a es_VE 240a es_CO 280a es_PE
              2c0a es_AR 300a es_EC 340a es_CL 380a es_UY 3c0a es_PY
              400a es_BO 440a es_SV 480a es_HN 4c0a es_NI 500a es_PR
        0b fi 040b fi_FI
        0c fr 040c fr_FR 080c fr_BE 0c0c fr_CA 100c fr_CH 140c fr_LU
              180c fr_MC
        0d he 040d he_IL
        0e hu 040e hu_HU
        0f is 040f is_IS
        10 it 0410 it_IT 0810 it_CH
        11 ja 0411 ja_JP
        12 ko 0412 ko_KR
        13 nl 0413 nl_NL 0813 nl_BE
        14 no 0414 no_NO 0814 nn_NO
        15 pl 0415 pl_PL
        16 pt 0416 pt_BR 0816 pt_PT
        17 rm 0417 rm_CH
        18 ro 0418 ro_RO
        19 ru
        1a hr 041a hr_HR 081a sr_YU 0c1a sr_YU@cyrillic
        1b sk 041b sk_SK
        1c sq 041c sq_AL
        1d sv 041d sv_SE 081d sv_FI
        1e th 041e th_TH
        1f tr 041f tr_TR
        20 ur 0420 ur_PK 0820 ur_IN
        21 id 0421 id_ID
        22 uk 0422 uk_UA
        23 be 0423 be_BY
        24 sl 0424 sl_SI
        25 et 0425 et_EE
        26 lv 0426 lv_LV
        27 lt 0427 lt_LT
        28 tg 0428 tg_TJ
        29 fa 0429 fa_IR
        2a vi 042a vi_VN
        2b hy 042b hy_AM
        2c az 042c az_AZ@latin 082c az_AZ@cyrillic
        2d eu
        2e wen 042e wen_DE
        2f mk 042f mk_MK
        30 bnt 0430 bnt_TZ
        31 ts 0431 ts_ZA
        33 ven 0433 ven_ZA
        34 xh 0434 xh_ZA
        35 zu 0435 zu_ZA
        36 af 0436 af_ZA
        37 ka 0437 ka_GE
        38 fo 0438 fo_FO
        39 hi 0439 hi_IN
        3a mt 043a mt_MT
        3b se 043b se_NO
        043c gd_UK 083c ga_IE
        3d yi 043d yi_IL
        3e ms 043e ms_MY 083e ms_BN
        3f kk 043f kk_KZ
        40 ky 0440 ky_KG
        41 sw 0441 sw_KE
        42 tk 0442 tk_TM
        43 uz 0443 uz_UZ@latin 0843 uz_UZ@cyrillic
        44 tt 0444 tt_RU
        45 bn 0445 bn_IN
        46 pa 0446 pa_IN
        47 gu 0447 gu_IN
        48 or 0448 or_IN
        49 ta
        4a te 044a te_IN
        4b kn 044b kn_IN
        4c ml 044c ml_IN
        4d as 044d as_IN
        4e mr 044e mr_IN
        4f sa 044f sa_IN
        50 mn
        51 bo 0451 bo_CN
        52 cy 0452 cy_GB
        53 km 0453 km_KH
        54 lo 0454 lo_LA
        55 my 0455 my_MM
        56 gl 0456 gl_ES
        57 kok 0457 kok_IN
        58 mni 0458 mni_IN
        59 sd
        5a syr 045a syr_TR
        5b si 045b si_LK
        5c chr 045c chr_US
        5d iu 045d iu_CA
        5e am 045e am_ET
        5f ber 045f ber_MA
        60 ks 0460 ks_PK 0860 ks_IN
        61 ne 0461 ne_NP 0861 ne_IN
        62 fy 0462 fy_NL
        63 ps
        64 tl 0464 tl_PH
        65 div 0465 div_MV
        66 bin 0466 bin_NG
        67 ful 0467 ful_NG
        68 ha 0468 ha_NG
        69 nic 0469 nic_NG
        6a yo 046a yo_NG
        70 ibo 0470 ibo_NG
        71 kau 0471 kau_NG
        72 om 0472 om_ET
        73 ti 0473 ti_ET
        74 gn 0474 gn_PY
        75 cpe 0475 cpe_US
        76 la 0476 la_VA
        77 so 0477 so_SO
        78 sit 0478 sit_CN
        79 pap 0479 pap_AN
    }
}

# msgcat::mc --
#
#	Find the translation for the given string based on the current
#	locale setting. Check the local namespace first, then look in each
#	parent namespace until the source is found.  If additional args are
#	specified, use the format command to work them into the traslated
#	string.
#
# Arguments:
#	src	The string to translate.
#	args	Args to pass to the format command
#
# Results:
#	Returns the translatd string.  Propagates errors thrown by the 
#	format command.

proc msgcat::mc {src args} {
    # Check for the src in each namespace starting from the local and
    # ending in the global.

    variable Msgs
    variable Loclist
    variable Locale

    set ns [uplevel 1 [list ::namespace current]]
    
    while {$ns != ""} {
	foreach loc $Loclist {
	    if {[info exists Msgs($loc,$ns,$src)]} {
		if {[llength $args] == 0} {
		    return $Msgs($loc,$ns,$src)
		} else {
		    return [uplevel 1 \
			    [linsert $args 0 ::format $Msgs($loc,$ns,$src)]]
		}
	    }
	}
	set ns [namespace parent $ns]
    }
    # we have not found the translation
    return [uplevel 1 \
	    [linsert $args 0 [::namespace origin mcunknown] $Locale $src]]
}

# msgcat::mclocale --
#
#	Query or set the current locale.
#
# Arguments:
#	newLocale	(Optional) The new locale string. Locale strings
#			should be composed of one or more sublocale parts
#			separated by underscores (e.g. en_US).
#
# Results:
#	Returns the current locale.

proc msgcat::mclocale {args} {
    variable Loclist
    variable Locale
    set len [llength $args]

    if {$len > 1} {
	error {wrong # args: should be "mclocale ?newLocale?"}
    }

    if {$len == 1} {
	set Locale [string tolower [lindex $args 0]]
	set Loclist {}
	set word ""
	foreach part [split $Locale _] {
	    set word [string trimleft "${word}_${part}" _]
	    set Loclist [linsert $Loclist 0 $word]
	}
    }
    return $Locale
}

# msgcat::mcpreferences --
#
#	Fetch the list of locales used to look up strings, ordered from
#	most preferred to least preferred.
#
# Arguments:
#	None.
#
# Results:
#	Returns an ordered list of the locales preferred by the user.

proc msgcat::mcpreferences {} {
    variable Loclist
    return $Loclist
}

# msgcat::mcload --
#
#	Attempt to load message catalogs for each locale in the
#	preference list from the specified directory.
#
# Arguments:
#	langdir		The directory to search.
#
# Results:
#	Returns the number of message catalogs that were loaded.

proc msgcat::mcload {langdir} {
    set x 0
    foreach p [mcpreferences] {
	set langfile [file join $langdir $p.msg]
	if {[file exists $langfile]} {
	    incr x
	    set fid [open $langfile "r"]
	    fconfigure $fid -encoding utf-8
            uplevel 1 [read $fid]
	    close $fid
	}
    }
    return $x
}

# msgcat::mcset --
#
#	Set the translation for a given string in a specified locale.
#
# Arguments:
#	locale		The locale to use.
#	src		The source string.
#	dest		(Optional) The translated string.  If omitted,
#			the source string is used.
#
# Results:
#	Returns the new locale.

proc msgcat::mcset {locale src {dest ""}} {
    variable Msgs
    if {[string equal $dest ""]} {
	set dest $src
    }

    set ns [uplevel 1 [list ::namespace current]]

    set Msgs([string tolower $locale],$ns,$src) $dest
    return $dest
}

# msgcat::mcmset --
#
#	Set the translation for multiple strings in a specified locale.
#
# Arguments:
#	locale		The locale to use.
#	pairs		One or more src/dest pairs (must be even length)
#
# Results:
#	Returns the number of pairs processed

proc msgcat::mcmset {locale pairs } {
    variable Msgs

    set length [llength $pairs]
    if {$length % 2} {
	error {bad translation list: should be "mcmset locale {src dest ...}"}
    }
    
    set locale [string tolower $locale]
    set ns [uplevel 1 [list ::namespace current]]
    
    foreach {src dest} $pairs {
        set Msgs($locale,$ns,$src) $dest
    }
    
    return $length
}

# msgcat::mcunknown --
#
#	This routine is called by msgcat::mc if a translation cannot
#	be found for a string.  This routine is intended to be replaced
#	by an application specific routine for error reporting
#	purposes.  The default behavior is to return the source string.  
#	If additional args are specified, the format command will be used
#	to work them into the traslated string.
#
# Arguments:
#	locale		The current locale.
#	src		The string to be translated.
#	args		Args to pass to the format command
#
# Results:
#	Returns the translated value.

proc msgcat::mcunknown {locale src args} {
    if {[llength $args]} {
	return [uplevel 1 [linsert $args 0 ::format $src]]
    } else {
	return $src
    }
}

# msgcat::mcmax --
#
#	Calculates the maximun length of the translated strings of the given 
#	list.
#
# Arguments:
#	args	strings to translate.
#
# Results:
#	Returns the length of the longest translated string.

proc msgcat::mcmax {args} {
    set max 0
    foreach string $args {
	set translated [uplevel 1 [list [namespace origin mc] $string]]
        set len [string length $translated]
        if {$len>$max} {
            set max $len
        }
    }
    return $max
}

# Convert the locale values stored in environment variables to a form
# suitable for passing to [mclocale]
proc msgcat::ConvertLocale {value} {
    # Assume $value is of form: $language[_$territory][.$codeset][@modifier]
    # Convert to form: $language[_$territory][_$modifier]
    #
    # Comment out expanded RE version -- bugs alleged
    # regexp -expanded {
    #	^		# Match all the way to the beginning
    #	([^_.@]*)	# Match "lanugage"; ends with _, ., or @
    #	(_([^.@]*))?	# Match (optional) "territory"; starts with _
    #	([.]([^@]*))?	# Match (optional) "codeset"; starts with .
    #	(@(.*))?	# Match (optional) "modifier"; starts with @
    #	$		# Match all the way to the end
    # } $value -> language _ territory _ codeset _ modifier
    regexp {^([^_.@]*)(_([^.@]*))?([.]([^@]*))?(@(.*))?$} $value \
	    -> language _ territory _ codeset _ modifier
    set ret $language
    if {[string length $territory]} {
	append ret _$territory
    }
    if {[string length $modifier]} {
	append ret _$modifier
    }
    return $ret
}

# Initialize the default locale
proc msgcat::Init {} {
    #
    # set default locale, try to get from environment
    #
    foreach varName {LC_ALL LC_MESSAGES LANG} {
	if {[info exists ::env($varName)] 
		&& ![string equal "" $::env($varName)]} {
            mclocale [ConvertLocale $::env($varName)]
	    return
	}
    }
    #
    # On Windows, try to set locale depending on registry settings,
    # or fall back on locale of "C".  Other platforms will return
    # when they fail to load the registry package.
    #
    set key {HKEY_CURRENT_USER\Control Panel\International}
    if {[catch {package require registry}] \
	    || [catch {registry get $key "locale"} locale]} {
        mclocale C
	return
    }
    #
    # Keep trying to match against smaller and smaller suffixes
    # of the registry value, since the latter hexadigits appear
    # to determine general language and earlier hexadigits determine
    # more precise information, such as territory.  For example,
    #     0409 - English - United States
    #     0809 - English - United Kingdom
    # Add more translations to the WinRegToISO639 array above.
    #
    variable WinRegToISO639
    set locale [string tolower $locale]
    while {[string length $locale]} {
        if {![catch {mclocale [ConvertLocale $WinRegToISO639($locale)]}]} {
	    return
	}
	set locale [string range $locale 1 end]
    }
    #
    # No translation known.  Fall back on "C" locale
    #
    mclocale C
}
msgcat::Init