@gctools-components/i18n-translation-webpack-plugin/dist/language.loader.js

Complete i18n translation solution for webpack, including code-splitting and automatic generation of translation files

'use strict';

/*
 * Author: National Research Council Canada
 * Website: http://www.nrc-cnrc.gc.ca/eng/rd/ict/
 *
 * License: MIT
 * Copyright: Her Majesty the Queen in Right of Canada, as represented by
 * the Minister of National Research Council, 2017
 */

var fs = require('fs');
var path = require('path');

/**
 * Loader responsible for injecting language data into bundle, and for code
 * splitting.
 */
module.exports = function I18nWebpackLoader() {
  if (this.cacheable) {
    this.cacheable();
  }
  var validCodeSplitting = ['language', 'domain', 'language+domain', 'all', 'none'];

  var optSplit = this.request.split('?options=')[1];
  var options = JSON.parse(decodeURIComponent(optSplit));

  var languages = options.languages;
  var context = this._compiler.context;

  var root = path.join(context, options.i18n_dir);

  if (!options.codeSplitting || validCodeSplitting.indexOf(options.codeSplitting) === -1) {
    options.codeSplitting = 'language';
  }

  var requires = [];
  requires = ['module.exports = function(lang, domain, cb) {\n'];

  Object.keys(languages).forEach(function (l) {
    var lang = languages[l];
    var filepath = path.join(root, lang + '/LC_MESSAGES');

    requires = requires.concat(['  if (lang == \'' + lang + '\') {\n']);

    if (options.codeSplitting === 'none') {
      requires = requires.concat(['  var req = require.context(\'' + root + '\', true, /.*\\.po$/);\n', '  cb(req(\'' + filepath + '/\' + domain + \'.po\'));']);
    } else if (options.codeSplitting === 'all') {
      requires = requires.concat(['  require.ensure([], function(require) {\n', '    cb(require(\'' + root + '\' + lang + \'/LC_MESSAGES/\'', '     + domain + \'.po\'));\n', '  });\n']);
    } else if (options.codeSplitting === 'language') {
      // code split by language
      var chunk = '/* webpackChunkName: "' + lang + '" */ ';
      var loader = '!json-loader!po-loader?format=jed1.x!';
      requires = requires.concat(['import(' + chunk + ' \'' + loader + filepath + '/\'+domain+\'.po\').then(cb);']);
    } else if (options.codeSplitting === 'domain') {
      // code split by domain
      var poFiles = fs.readdirSync(path.join(root, filepath)).filter(function (file) {
        return file.indexOf('.po') > 2;
      });
      Object.keys(poFiles).forEach(function (po) {
        var domain = poFiles[po].slice(0, -3);
        requires = requires.concat(['    if (domain == \'' + domain + '\') {\n', '      require.ensure([], function(require) {\n', '      var req = require.context(\'' + root + '\',true,/\\.\\/' + lang, '\\/LC_MESSAGES\\/' + domain.replace('.', '\\.') + '\\.po/);\n', '        cb(req(\'' + path.join(filepath, domain) + '\' + \'.po\'', '));\n', '      }, \'' + domain + '\');\n', '    }\n']);
      });
    } else if (options.codeSplitting === 'language+domain') {
      // code split by domain AND language.
      var _poFiles = fs.readdirSync(path.join(root, filepath)).filter(function (file) {
        return file.indexOf('.po') > 2;
      });
      var co = '' + root + path.sep + lang + '/LC_MESSAGES/';
      Object.keys(_poFiles).forEach(function (po) {
        var domain = _poFiles[po].slice(0, -3);
        requires = requires.concat(['    if (domain == \'' + domain + '\') {\n', '      require.ensure([], function(require) {\n', '      var req = require.context(\'' + co + '\', ', 'false, /\\.\\/' + domain.replace('.', '\\.') + '\\.po/);\n', '        cb(req(\'./' + domain + '\' + \'.po\'', '));\n', '      }, \'' + lang + '-' + domain + '\');\n', '    }\n']);
      });
    }
    requires = requires.concat(['  }\n']);
  });

  requires = requires.concat(['}']);
  return requires.join('');
};