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- var fs = require('fs')
- var path = require('path')
- var util = require('util')
-
- function Y18N (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 = {}
- this.writeQueue = []
- }
-
- Y18N.prototype.__ = function () {
- if (typeof arguments[0] !== 'string') {
- return this._taggedLiteral.apply(this, arguments)
- }
- var args = Array.prototype.slice.call(arguments)
- var str = args.shift()
- var 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([this.directory, this.locale, cb])
- } else {
- cb()
- }
-
- return util.format.apply(util, [this.cache[this.locale][str] || str].concat(args))
- }
-
- Y18N.prototype._taggedLiteral = function (parts) {
- var args = arguments
- var str = ''
- parts.forEach(function (part, i) {
- var arg = args[i + 1]
- str += part
- if (typeof arg !== 'undefined') {
- str += '%s'
- }
- })
- return this.__.apply(null, [str].concat([].slice.call(arguments, 1)))
- }
-
- Y18N.prototype._enqueueWrite = function (work) {
- this.writeQueue.push(work)
- if (this.writeQueue.length === 1) this._processWriteQueue()
- }
-
- Y18N.prototype._processWriteQueue = function () {
- var _this = this
- var work = this.writeQueue[0]
-
- // destructure the enqueued work.
- var directory = work[0]
- var locale = work[1]
- var cb = work[2]
-
- var languageFile = this._resolveLocaleFile(directory, locale)
- var serializedLocale = JSON.stringify(this.cache[locale], null, 2)
-
- fs.writeFile(languageFile, serializedLocale, 'utf-8', function (err) {
- _this.writeQueue.shift()
- if (_this.writeQueue.length > 0) _this._processWriteQueue()
- cb(err)
- })
- }
-
- Y18N.prototype._readLocaleFile = function () {
- var localeLookup = {}
- var languageFile = this._resolveLocaleFile(this.directory, this.locale)
-
- try {
- localeLookup = JSON.parse(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
- }
-
- Y18N.prototype._resolveLocaleFile = function (directory, locale) {
- var file = path.resolve(directory, './', locale + '.json')
- if (this.fallbackToLanguage && !this._fileExistsSync(file) && ~locale.lastIndexOf('_')) {
- // attempt fallback to language only
- var languageFile = path.resolve(directory, './', locale.split('_')[0] + '.json')
- if (this._fileExistsSync(languageFile)) file = languageFile
- }
- return file
- }
-
- // this only exists because fs.existsSync() "will be deprecated"
- // see https://nodejs.org/api/fs.html#fs_fs_existssync_path
- Y18N.prototype._fileExistsSync = function (file) {
- try {
- return fs.statSync(file).isFile()
- } catch (err) {
- return false
- }
- }
-
- Y18N.prototype.__n = function () {
- var args = Array.prototype.slice.call(arguments)
- var singular = args.shift()
- var plural = args.shift()
- var quantity = args.shift()
-
- var cb = function () {} // start with noop.
- if (typeof args[args.length - 1] === 'function') cb = args.pop()
-
- if (!this.cache[this.locale]) this._readLocaleFile()
-
- var str = quantity === 1 ? singular : plural
- if (this.cache[this.locale][singular]) {
- str = this.cache[this.locale][singular][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([this.directory, this.locale, cb])
- } else {
- cb()
- }
-
- // if a %d placeholder is provided, add quantity
- // to the arguments expanded by util.format.
- var values = [str]
- if (~str.indexOf('%d')) values.push(quantity)
-
- return util.format.apply(util, values.concat(args))
- }
-
- Y18N.prototype.setLocale = function (locale) {
- this.locale = locale
- }
-
- Y18N.prototype.getLocale = function () {
- return this.locale
- }
-
- Y18N.prototype.updateLocale = function (obj) {
- if (!this.cache[this.locale]) this._readLocaleFile()
-
- for (var key in obj) {
- this.cache[this.locale][key] = obj[key]
- }
- }
-
- module.exports = function (opts) {
- var y18n = new Y18N(opts)
-
- // bind all functions to y18n, so that
- // they can be used in isolation.
- for (var key in y18n) {
- if (typeof y18n[key] === 'function') {
- y18n[key] = y18n[key].bind(y18n)
- }
- }
-
- return y18n
- }
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