Add plocale.eclass

eclass/plocale.eclass

@@ -0,0 +1,169 @@
+# Copyright 1999-2021 Gentoo Foundation
+# Distributed under the terms of the GNU General Public License v2
+# @ECLASS: plocale.eclass
+# @MAINTAINER:
+# Ulrich Müller <[email protected]>
+# @AUTHOR:
+# Ben de Groot <[email protected]>
+# @SUPPORTED_EAPIS: 6 7 8
+# @BLURB: convenience functions to handle localizations
+# @DESCRIPTION:
+# The plocale (localization) eclass offers a number of functions to more
+# conveniently handle localizations (translations) offered by packages.
+# These are meant to prevent code duplication for such boring tasks as
+# determining the cross-section between the user's set LINGUAS and what
+# is offered by the package.
+#
+# Typical usage in an ebuild looks like this:
+#
+# @CODE
+#   PLOCALES="de en fr pt_BR zh_CN"
+#   PLOCALE_BACKUP="en"
+# @CODE
+#
+# There, PLOCALES is the list of locales that the package supports.
+# PLOCALE_BACKUP is optional and specifies a single locale, which is
+# used as a fallback if none of the PLOCALES matches the user's
+# LINGUAS selection.
+#
+# The eclass functions then operate on the intersection of the package's
+# PLOCALES with the user's LINGUAS setting.  (As a special case, if the
+# LINGUAS variable is unset then all items in PLOCALES will be used,
+# emulating the behaviour of gettext.)
+
+# In the following simple example, locale specific README files
+# (e.g. README.de, README.en) are added to the DOCS variable:
+#
+# @CODE
+#   my_add_to_docs() {
+#       DOCS+=( ${1}.${2} )
+#   }
+#   plocale_for_each_locale my_add_to_docs README
+# @CODE
+#
+# A complementary function plocale_for_each_disabled_locale exists as
+# well, which operates on the set difference of PLOCALES and LINGUAS,
+# i.e. on the locales that the user hasn't enabled.  For example, it can
+# be used to remove unnecessary locale files.
+#
+# Finally, plocale_find_changes is purely a helper function for ebuild
+# maintenance.  It can be used to scan a directory for available
+# translations and check if the ebuild's PLOCALES are still up to date.
+
+case ${EAPI} in
+	6|7|8) ;;
+	*) die "${ECLASS}: EAPI ${EAPI:-0} not supported" ;;
+esac
+
+if [[ -z ${_PLOCALE_ECLASS} ]]; then
+_PLOCALE_ECLASS=1
+
+# @ECLASS-VARIABLE: PLOCALES
+# @DEFAULT_UNSET
+# @DESCRIPTION:
+# Variable listing the locales for which localizations are offered by
+# the package.
+#
+# Example: PLOCALES="cy de el_GR en_US pt_BR vi zh_CN"
+
+# @ECLASS-VARIABLE: PLOCALE_BACKUP
+# @DEFAULT_UNSET
+# @DESCRIPTION:
+# In some cases the package fails when none of the offered PLOCALES are
+# selected by the user.  In that case this variable should be set to a
+# default locale (usually 'en' or 'en_US') as backup.
+#
+# Example: PLOCALE_BACKUP="en_US"
+
+# @FUNCTION: plocale_for_each_locale
+# @USAGE: <function> [<args>...]
+# @DESCRIPTION:
+# Convenience function for processing all enabled localizations.
+# The parameter should be a function (defined in the consuming eclass
+# or ebuild) which takes an individual locale as its (last) parameter.
+#
+# Example: plocale_for_each_locale install_locale
+plocale_for_each_locale() {
+	local locs x
+	locs=$(plocale_get_locales)
+	for x in ${locs}; do
+		"$@" ${x} || die "failed to process enabled ${x} locale"
+	done
+}
+
+# @FUNCTION: plocale_for_each_disabled_locale
+# @USAGE: <function> [<args>...]
+# @DESCRIPTION:
+# Complementary to plocale_for_each_locale, this function will process
+# locales that are disabled.  This could be used for example to remove
+# locales from a Makefile, to prevent them from being built needlessly.
+plocale_for_each_disabled_locale() {
+	local locs x
+	locs=$(plocale_get_locales disabled)
+	for x in ${locs}; do
+		"$@" ${x} || die "failed to process disabled ${x} locale"
+	done
+}
+
+# @FUNCTION: plocale_find_changes
+# @USAGE: <translations dir> <filename pre pattern> <filename post pattern>
+# @DESCRIPTION:
+# Ebuild maintenance helper function to find changes in package offered
+# locales when doing a version bump.  This could be added for example
+# to src_prepare.
+#
+# Example: plocale_find_changes "${S}/src/translations" "${PN}_" '.ts'
+plocale_find_changes() {
+	[[ $# -eq 3 ]] || die "Exactly 3 arguments are needed!"
+	ebegin "Looking in ${1} for new locales"
+	pushd "${1}" >/dev/null || die "Cannot access ${1}"
+	local current="" x
+	for x in ${2}*${3}; do
+		x=${x#"${2}"}
+		x=${x%"${3}"}
+		current+="${x} "
+	done
+	popd >/dev/null || die
+	# RHS will be sorted with single spaces so ensure the LHS is too
+	# before attempting to compare them for equality. See bug #513242.
+	# Run them both through the same sorting algorithm so we don't have
+	# to worry about them being the same.
+	[[ "$(printf '%s\n' ${PLOCALES} | LC_ALL=C sort)" \
+		== "$(printf '%s\n' ${current} | LC_ALL=C sort)" ]]
+	if ! eend $? "There are changes in locales!"; then
+		eerror "This ebuild should be updated to:"
+		eerror "PLOCALES=\"${current%[[:space:]]}\""
+		return 1
+	fi
+}
+
+# @FUNCTION: plocale_get_locales
+# @USAGE: [disabled]
+# @DESCRIPTION:
+# Determine which LINGUAS the user has enabled that are offered by the
+# package, as listed in PLOCALES, and return them.  In case no locales
+# are selected, fall back on PLOCALE_BACKUP.  When the disabled argument
+# is given, return the disabled locales instead of the enabled ones.
+plocale_get_locales() {
+	local loc locs
+	if [[ -z ${LINGUAS+set} ]]; then
+		# enable all if unset
+		locs=${PLOCALES}
+	else
+		for loc in ${LINGUAS}; do
+			has ${loc} ${PLOCALES} && locs+="${loc} "
+		done
+	fi
+	[[ -z ${locs} ]] && locs=${PLOCALE_BACKUP}
+	if [[ ${1} == disabled ]]; then
+		local disabled_locs
+		for loc in ${PLOCALES}; do
+			has ${loc} ${locs} || disabled_locs+="${loc} "
+		done
+		locs=${disabled_locs}
+	fi
+	printf "%s" "${locs}"
+}
+
+fi
+