Simple express server that exposes a Transifex project's resources as a requirejs i18n bundle.

app.js

const PORT = process.env['PORT'] || 3000;
const PROJECT = process.env['TRANSIFEX_PROJECT'] || 'friendlycode';
const USERPASS = process.env['TRANSIFEX_USERPASS'] || '';
const ROOT_LOCALE = process.env['TRANSIFEX_ROOT_LOCALE'] || 'en';
const AUTH_HEADER = 'Basic ' + new Buffer(USERPASS).toString('base64');
const BASE_TRANSIFEX_URL = 'https://www.transifex.com/api/2/project/' +
                           PROJECT;
const REVIEWED_RE = /^\/reviewed\/(.*)$/;
const TOPLEVEL_RE = /^\/(.*)\/nls\/([A-Za-z0-9\-_]+)\.js$/;
const LOCALE_RE = /^\/(.*)\/nls\/([a-z\-]+)\/([A-Za-z0-9\-_]+)\.js$/;
const TRANSIFEX_CACHE_TIME = 30000;

var express = require('express');
var request = require('request');
var app = express();
var transifexCache = {}; // Not 12-factor compliant, but it'll do.

var toTransifexLocale = exports.toTransifexLocale = function(locale) {
  var parts = locale.split(/[-_]/);
  if (parts.length >= 2)
    return parts[0].toLowerCase() + "_" + parts[1].toUpperCase();
  return parts[0].toLowerCase();
};

var toBundleLocale = exports.toBundleLocale = function(locale) {
  return locale.toLowerCase().replace(/_/g, '-');
};

var toBundleMetadata = exports.toBundleMetadata = function(resource) {
  var metadata = {};
  resource.available_languages.forEach(function(language) {
    if (language.code == resource.source_language_code)
      return metadata.root = true;
    metadata[toBundleLocale(language.code)] = true;
  });
  return metadata;
};

var toBundleDict = exports.toBundleDict = function(options) {
  var dict = {};
  options.strings.forEach(function(info) {
    if (!info.translation) return;
    if (options.reviewedOnly && !info.reviewed) return;
    dict[info.key] = info.translation;
  });
  return dict;
};

function slugify(name) {
  var slug = [];
  for (var i = 0; i < name.length; i++)
    if (name[i].match(/[A-Za-z\-_0-9]/))
      slug.push(name[i]);
  return slug.join('');
}

function sendExportsAsModule(exports, res) {
  var js = "define(" + JSON.stringify(exports, null, 2) + ");";
  res.set('Content-Type', 'application/javascript; charset=utf-8');
  return res.send(js);
}

function transifexRequest(toplevelModule, path, res, cb) {
  var url = '/resource/' + slugify(toplevelModule) + path;
  
  if (url in transifexCache && transifexCache[url].expiry > Date.now())
    cb(JSON.parse(transifexCache[url].body));
  else
    request.get({
      url: BASE_TRANSIFEX_URL + url,
      headers: {'Authorization': AUTH_HEADER}
    }, function(error, response, body) {
      if (error) {
        console.log("ERROR", error);
        return res.send(500);
      }
      if (response.statusCode == 404)
        return res.send(404);
      if (response.statusCode != 200) {
        console.log("transifex returned " + response.statusCode);
        return res.send(502);
      }
      transifexCache[url] = {
        expiry: Date.now() + TRANSIFEX_CACHE_TIME,
        body: body
      };
      cb(JSON.parse(body));
    });
}

function main(app) {
  if (!USERPASS)
    throw new Error('user:pass not in TRANSIFEX_USERPASS env var');

  app.listen(PORT, function() {
    console.log("listening on port " + PORT);
  });
}

app.use(function parseReviewedOnlyPrefix(req, res, next) {
  var reviewedMatch = req.url.match(REVIEWED_RE);
  var reviewedOnly = false;
  var path;
  if (reviewedMatch) {
    path = '/' + reviewedMatch[1];
    reviewedOnly = true;
  } else {
    path = req.url;
  }
  req.i18n = {
    path: path,
    reviewedOnly: reviewedOnly
  };
  next();
});

app.use(function handleI18nToplevelModule(req, res, next) {
  var toplevelMatch = req.i18n.path.match(TOPLEVEL_RE);
  if (toplevelMatch) {
    var toplevelModule = toplevelMatch[1] + '/nls/' + toplevelMatch[2];
    
    return transifexRequest(toplevelModule, '/?details', res, function(obj) {
      return sendExportsAsModule(toBundleMetadata(obj), res);
    });
  }
  next();
});

app.use(function handleI18nLocaleModule(req, res, next) {
  var localeMatch = req.i18n.path.match(LOCALE_RE);
  if (localeMatch) {
    var locale = localeMatch[2];
    var toplevelModule = localeMatch[1] + '/nls/' + localeMatch[3];
    var path;
    
    if (locale == 'root')
      locale = ROOT_LOCALE;

    path = '/translation/' + toTransifexLocale(locale) + '/strings/';

    return transifexRequest(toplevelModule, path, res, function(obj) {
      return sendExportsAsModule(toBundleDict({
        strings: obj,
        reviewedOnly: req.i18n.reviewedOnly
      }), res);
    });
  }
  next();
});

if (!module.parent) main(app);

package.json

{
  "name": "transifex-to-requirejs-i18n-server",
  "version": "0.0.1",
  "description": "Server that converts a Transifex project to requirejs i18n bundles",
  "main": "app.js",
  "dependencies": {
    "express": "3.0.6",
    "request": "2.12.0"
  },
  "devDependencies": {},
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "repository": "",
  "author": "Atul Varma",
  "license": "BSD"
}

For more information on what this is used for, see mozilla/friendlycode#175.