blob: e38f33594c158b6335ef049f35a0ed18abf7d2d0 [file] [log] [blame]
let shim;
class Y18N {
constructor(opts) {
// configurable options.
opts = opts || {};
this.directory = opts.directory || './locales';
this.updateFiles = typeof opts.updateFiles === 'boolean' ? opts.updateFiles : true;
this.locale = opts.locale || 'en';
this.fallbackToLanguage = typeof opts.fallbackToLanguage === 'boolean' ? opts.fallbackToLanguage : true;
// internal stuff.
this.cache = Object.create(null);
this.writeQueue = [];
}
__(...args) {
if (typeof arguments[0] !== 'string') {
return this._taggedLiteral(arguments[0], ...arguments);
}
const str = args.shift();
let cb = function () { }; // start with noop.
if (typeof args[args.length - 1] === 'function')
cb = args.pop();
cb = cb || function () { }; // noop.
if (!this.cache[this.locale])
this._readLocaleFile();
// we've observed a new string, update the language file.
if (!this.cache[this.locale][str] && this.updateFiles) {
this.cache[this.locale][str] = str;
// include the current directory and locale,
// since these values could change before the
// write is performed.
this._enqueueWrite({
directory: this.directory,
locale: this.locale,
cb
});
}
else {
cb();
}
return shim.format.apply(shim.format, [this.cache[this.locale][str] || str].concat(args));
}
__n() {
const args = Array.prototype.slice.call(arguments);
const singular = args.shift();
const plural = args.shift();
const quantity = args.shift();
let cb = function () { }; // start with noop.
if (typeof args[args.length - 1] === 'function')
cb = args.pop();
if (!this.cache[this.locale])
this._readLocaleFile();
let str = quantity === 1 ? singular : plural;
if (this.cache[this.locale][singular]) {
const entry = this.cache[this.locale][singular];
str = entry[quantity === 1 ? 'one' : 'other'];
}
// we've observed a new string, update the language file.
if (!this.cache[this.locale][singular] && this.updateFiles) {
this.cache[this.locale][singular] = {
one: singular,
other: plural
};
// include the current directory and locale,
// since these values could change before the
// write is performed.
this._enqueueWrite({
directory: this.directory,
locale: this.locale,
cb
});
}
else {
cb();
}
// if a %d placeholder is provided, add quantity
// to the arguments expanded by util.format.
const values = [str];
if (~str.indexOf('%d'))
values.push(quantity);
return shim.format.apply(shim.format, values.concat(args));
}
setLocale(locale) {
this.locale = locale;
}
getLocale() {
return this.locale;
}
updateLocale(obj) {
if (!this.cache[this.locale])
this._readLocaleFile();
for (const key in obj) {
if (Object.prototype.hasOwnProperty.call(obj, key)) {
this.cache[this.locale][key] = obj[key];
}
}
}
_taggedLiteral(parts, ...args) {
let str = '';
parts.forEach(function (part, i) {
const arg = args[i + 1];
str += part;
if (typeof arg !== 'undefined') {
str += '%s';
}
});
return this.__.apply(this, [str].concat([].slice.call(args, 1)));
}
_enqueueWrite(work) {
this.writeQueue.push(work);
if (this.writeQueue.length === 1)
this._processWriteQueue();
}
_processWriteQueue() {
const _this = this;
const work = this.writeQueue[0];
// destructure the enqueued work.
const directory = work.directory;
const locale = work.locale;
const cb = work.cb;
const languageFile = this._resolveLocaleFile(directory, locale);
const serializedLocale = JSON.stringify(this.cache[locale], null, 2);
shim.fs.writeFile(languageFile, serializedLocale, 'utf-8', function (err) {
_this.writeQueue.shift();
if (_this.writeQueue.length > 0)
_this._processWriteQueue();
cb(err);
});
}
_readLocaleFile() {
let localeLookup = {};
const languageFile = this._resolveLocaleFile(this.directory, this.locale);
try {
// When using a bundler such as webpack, readFileSync may not be defined:
if (shim.fs.readFileSync) {
localeLookup = JSON.parse(shim.fs.readFileSync(languageFile, 'utf-8'));
}
}
catch (err) {
if (err instanceof SyntaxError) {
err.message = 'syntax error in ' + languageFile;
}
if (err.code === 'ENOENT')
localeLookup = {};
else
throw err;
}
this.cache[this.locale] = localeLookup;
}
_resolveLocaleFile(directory, locale) {
let file = shim.resolve(directory, './', locale + '.json');
if (this.fallbackToLanguage && !this._fileExistsSync(file) && ~locale.lastIndexOf('_')) {
// attempt fallback to language only
const languageFile = shim.resolve(directory, './', locale.split('_')[0] + '.json');
if (this._fileExistsSync(languageFile))
file = languageFile;
}
return file;
}
_fileExistsSync(file) {
return shim.exists(file);
}
}
export function y18n(opts, _shim) {
shim = _shim;
const y18n = new Y18N(opts);
return {
__: y18n.__.bind(y18n),
__n: y18n.__n.bind(y18n),
setLocale: y18n.setLocale.bind(y18n),
getLocale: y18n.getLocale.bind(y18n),
updateLocale: y18n.updateLocale.bind(y18n),
locale: y18n.locale
};
}