scripts/python/Makefile.am, configure.ac, docs/config-prereqs.txt: us…

…e gettext msgfmt to compile binary translation files

configure.ac

@@ -1558,6 +1558,12 @@ dnl installing these features or not.
 dnl Note: more for tests than other reasons, there is also an option
 dnl value to "force" the installation.
 
+dnl The gettext "msgfmt" tool (or equivalent) can be used to maintain
+dnl human-language text translations. Currently this is used specifically
+dnl in the Python NUT-Monitor app sources (*.po => *.mo conversions).
+AC_PATH_PROGS([MSGFMT], [msgfmt], [none])
+AM_CONDITIONAL([HAVE_MSGFMT], [test "x${MSGFMT}" != "xnone"])
+
 dnl ----------------------------------------------------------------------
 dnl checks related to --with-serial
 

docs/config-prereqs.txt

@@ -141,6 +141,15 @@ metadata about recently published package revisions:
 #   :; apt-get install python3 python3.9
 # You can find a list of what is (pre-)installed with:
 #   :; dpkg -l | grep -Ei 'perl|python'
+#
+# For localization maintenance (currently in Python NUT-Monitor app),
+# provide an `msgfmt` implementation, e.g.:
+#   :; apt-get install gettext
+#
+# To install the Python NUT-Monitor app, you may need some modules:
+#   :; apt-get install pip
+# For Python3:
+#   :; pip install PyQt5 configparser
 
 # For spell-checking, highly recommended if you would propose pull requests:
 :; apt-get install \

scripts/python/Makefile.am

@@ -24,6 +24,10 @@ PYTHON3_SITE_PACKAGES = @PYTHON3_SITE_PACKAGES@
 
 BINDIR = @BINDIR@
 
+if HAVE_MSGFMT
+MSGFMT = @MSGFMT@
+endif HAVE_MSGFMT
+
 NUT_MONITOR_PY2GTK2 = \
 	app/ui/gui-1.3.glade \
 	app/nut-monitor-py2gtk2.desktop
@@ -71,7 +75,7 @@ PYNUT_COMMON = \
 	module/README
 
 # Note: we both distribute and install the generated *.mo translation files
-# so they are listed above and not in NUT_MONITOR_COMMON_GENERATED
+# so they are listed above and not in NUT_MONITOR_COMMON_TEMPLATE
 NUT_MONITOR_COMMON_TEMPLATE = \
 	app/locale/NUT-Monitor.pot \
 	app/locale/fr/fr.po \
@@ -113,6 +117,17 @@ nutmonitordir = $(nut_with_nut_monitor_dir)
 nobase_nutmonitor_DATA = $(NUT_MONITOR_DISPATCHER_NOEXEC) $(NUT_MONITOR_COMMON)
 nobase_nutmonitor_SCRIPTS = $(NUT_MONITOR_DISPATCHER_SCRIPT)
 
+if HAVE_MSGFMT
+app/locale/fr/LC_MESSAGES/NUT-Monitor.mo: app/locale/fr/fr.po
+	$(MSGFMT) -c "$<" -o "$@"
+
+app/locale/it/LC_MESSAGES/NUT-Monitor.mo: app/locale/it/it.po
+	$(MSGFMT) -c "$<" -o "$@"
+
+app/locale/ru/LC_MESSAGES/NUT-Monitor.mo: app/locale/ru/ru.po
+	$(MSGFMT) -c "$<" -o "$@"
+endif HAVE_MSGFMT
+
 if WITH_NUT_MONITOR_PY2GTK2
 nobase_nutmonitor_DATA += $(NUT_MONITOR_PY2GTK2)
 nobase_nutmonitor_SCRIPTS += $(NUT_MONITOR_PY2GTK2_GENERATED_SCRIPT)