reads app component.json and serves the files associated with them

componentLoader_middleware.js

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

module.exports = function (rootComponentPath) {
  var componentBase, modules, modPaths, modRoutes;

  modPaths = [];
  modRoutes = {};

  rootComponentPath = rootComponentPath || '.';

  componentBase = require(path.resolve(rootComponentPath, './component.json'));

  modules = Object.keys(componentBase.dependencies);
  modules.forEach(function (componentName) {
    var componentPath = path.resolve('./components', componentName),
        componentJsonPath = path.join(componentPath, 'component.json'),
        componentJson = require(componentJsonPath);
    switch (typeof componentJson.main) {
      case 'object':
        var arr;
        if (componentJson.main instanceof Array) {
          arr = componentJson.main;
        } else {
          arr = Object.keys(componentJson.main);
        }
        arr.forEach(function(k) { modPaths.push(path.resolve(componentPath, k)); });
        break;
      case 'string':
        modPaths.push(path.resolve(componentPath, componentJson.main));
        break;
      default:
        //noop
        break;
    }
  });

  modPaths.forEach(function (modPath) {
    var fileName = modPath.split('/').pop();
    modRoutes[fileName] = modPath;
  });

  return function (req, res, next) {
    var fileName = req.url.substring(1),
        filePath = modRoutes[fileName];
    if (filePath) {
      var fileStream = fs.createReadStream(filePath);
      res.writeHead(200);
      fileStream.pipe(res);
    } else {
      next();
    }
  };
};