inline compressed static files for express

app.danamicHelpers.js

var conf = central.conf;
var reg_val = /#{([^}]+)}/g;

module.exports = function(app) {
  app.helpers({
    DEBUG: conf.debug
  });
  app.dynamicHelpers({
    // inline static
    istatic: function(req, res) {
      return function() {
        var locals = this;
        var str = central.utils.istatic.apply(central.utils, arguments) || '';
        // replace inlined arguments
        if (str.indexOf('#{') > -1) {
          str = str.replace(reg_val, function(p0, p1) {
            // look like dangerous...
            var fn = new Function('locals', 'with (locals) { return ' + p1 + '; }');
            return fn(locals);
          });
        }
        return str;
      };
    }
  });
};

central.utils.js

var fs = require('fs');
var less = require('less');
var uglifycss = require('uglifycss');
var jsp = require('uglify-js').parser;
var pro = require('uglify-js').uglify;


var central = global.central = { lazylid: {}, cwd: process.cwd(), conf: { debug: false; } };

module.exports = {
  uglify: function uglify(str, opt) {
    if (global.central && central.conf.debug) return str;
    var ast = jsp.parse(str); // parse code and get the initial AST
    ast = pro.ast_mangle(ast); // get a new AST with mangled names
    ast = pro.ast_squeeze(ast); // get an AST with compression optimizations
    return pro.gen_code(ast, opt); // compressed code here
  },
  uglifycss: function uglifycss(str) {
    return uglifycss.processString(str);
  },
  // inline static files
  istatic: function istatic(path, forceReload) {
    var ft = path.split('.').slice(-1)[0];
    var root = central.cwd + (path[0] == '/' ? '' : '/public/');
    path = root + path;

    var str = central.lazylib[path];
    var notDebug = !central.conf.debug;

    if (!str || forceReload) {
      str = fs.readFileSync(path, 'utf-8');
      switch (ft) {
        case 'js':
          // if not debug, uglify the js
          if (notDebug) str = module.exports.uglify(str);
          break;
        case 'less':
          less.render(str, function(err, str) {
            if (notDebug) str = uglifystr(str);
            if (!err) central.lazylib[path] = str;
          });
          // better simple than none
          // once the render is done, we can safely return good css
          break;
        case 'css':
          if (notDebug) str = module.exports.uglifycss(str);
        default:
          // return the original str
      }
      central.lazylib[path] = str;
    }

    return str;
  }
}

central.utils = module.exports;