gotosocial/internal/language/language.go

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// GoToSocial
// Copyright (C) GoToSocial Authors admin@gotosocial.org
// SPDX-License-Identifier: AGPL-3.0-or-later
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package language
import (
"github.com/superseriousbusiness/gotosocial/internal/gtserror"
"golang.org/x/text/language"
"golang.org/x/text/language/display"
)
var namer display.Namer
// InitLangs parses languages from the
// given slice of tags, and sets the `namer`
// display.Namer for the instance.
//
// This function should only be called once,
// since setting the namer is not thread safe.
func InitLangs(tagStrs []string) (Languages, error) {
var (
languages = make(Languages, len(tagStrs))
tags = make([]language.Tag, len(tagStrs))
)
// Reset namer.
namer = nil
// Parse all tags first.
for i, tagStr := range tagStrs {
tag, err := language.Parse(tagStr)
if err != nil {
return nil, gtserror.Newf(
"error parsing %s as BCP47 language tag: %w",
tagStr, err,
)
}
tags[i] = tag
}
// Check if we can set a namer.
if len(tags) != 0 {
namer = display.Languages(tags[0])
}
// Fall namer back to English.
if namer == nil {
namer = display.Languages(language.English)
}
// Parse nice language models from tags
// (this will use the namer we just set).
for i, tag := range tags {
languages[i] = ParseTag(tag)
}
return languages, nil
}
// Language models a BCP47 language tag
// along with helper strings for the tag.
type Language struct {
// BCP47 language tag
Tag language.Tag
// Normalized string
// of BCP47 tag.
TagStr string
// Human-readable
// language name(s).
DisplayStr string
}
// MarshalText implements encoding.TextMarshaler{}.
func (l *Language) MarshalText() ([]byte, error) {
return []byte(l.TagStr), nil
}
// UnmarshalText implements encoding.TextUnmarshaler{}.
func (l *Language) UnmarshalText(text []byte) error {
lang, err := Parse(string(text))
if err != nil {
return err
}
*l = *lang
return nil
}
type Languages []*Language
func (l Languages) Tags() []language.Tag {
tags := make([]language.Tag, len(l))
for i, lang := range l {
tags[i] = lang.Tag
}
return tags
}
func (l Languages) TagStrs() []string {
tagStrs := make([]string, len(l))
for i, lang := range l {
tagStrs[i] = lang.TagStr
}
return tagStrs
}
func (l Languages) DisplayStrs() []string {
displayStrs := make([]string, len(l))
for i, lang := range l {
displayStrs[i] = lang.DisplayStr
}
return displayStrs
}
// ParseTag parses and nicely formats the input language BCP47 tag,
// returning a Language with ready-to-use display and tag strings.
func ParseTag(tag language.Tag) *Language {
l := new(Language)
l.Tag = tag
l.TagStr = tag.String()
var (
// Our name for the language.
name string
// Language's name for itself.
selfName = display.Self.Name(tag)
)
// Try to use namer
// (if initialized).
if namer != nil {
name = namer.Name(tag)
}
switch {
case name == "":
// We don't have a name for
// this language, just use
// its own name for itself.
l.DisplayStr = selfName
case name == selfName:
// Avoid repeating ourselves:
// showing "English (English)"
// is not useful.
l.DisplayStr = name
default:
// Include our name for the
// language, and its own
// name for itself.
l.DisplayStr = name + " " + "(" + selfName + ")"
}
return l
}
// Parse parses and nicely formats the input language BCP47 tag,
// returning a Language with ready-to-use display and tag strings.
func Parse(lang string) (*Language, error) {
tag, err := language.Parse(lang)
if err != nil {
return nil, err
}
return ParseTag(tag), nil
}