grunt-connect-route/lib/utils.js

Provides RewriteRules middleware for the grunt connect and express.

/*
* grunt-connect-rewrite
* https://github.com/viart/grunt-connect-rewrite
*
* Copyright (c) 2013 Artem Vitiuk
* Licensed under the MIT license.
*/


'use strict';

var fs = require('fs'),
  url = require('url'),
  http = require('http'),
  httpProxy = require('http-proxy-zz'),
  path = require('path'),
  querystring = require('querystring'),
  utils = module.exports,
  rules = [];

utils.registerRule = function (rule) {

  if (!rule || !rule.from || !rule.to ||
    !(rule.from = rule.from.trim()) ||
    !(rule.from = rule.from.trim())) {
      return false;
    }

    var ruleItem = {
      from: new RegExp(rule.from),
      to: rule.to
    };

    if (rule.to.indexOf('http://') === 0) {
      var urlObject = url.parse(rule.to);
      ruleItem.proxy = new httpProxy.HttpProxy({
        target: {
          host: urlObject.hostname,
          port: urlObject.port || '',
          https: urlObject.protocol === 'https:'
        },
        changeOrigin: true
      });
    }
    rules.push(ruleItem);

    return true;
  };

  utils.resetRules = function () {
    rules = [];
  };

  utils.rules = function () {
    return rules;
  };

  function requireUncached(module){
    delete require.cache[require.resolve(module)];
    return require(module);
  }

  utils.dispatcher = function (req, res) {
    return function (rule) {
      if (rule.from.test(req.url)) {
        if (rule.to.indexOf('require!') === 0) {
          var urlObject = url.parse(req.url);
          // require
          var filepath = urlObject.pathname.replace(rule.from, rule.to).replace('require!', '');
          var realpath = path.join(process.cwd(), filepath);
          // var parameters = querystring.parse(urlObject.query);
          if (fs.existsSync(realpath)) {
            res.setHeader('Content-Type', 'application/json');
            requireUncached(realpath)(req, res);
            //res.end(JSON.stringify(data));
            return true;
          }
        } else if (rule.to.indexOf('http://') === 0 && rule.proxy) {
          // internet url
          rule.proxy.proxyRequest(req, res);
          return true;
        } else {
          // redirect
          req.url = req.url.replace(rule.from, rule.to);
          return true;
        }

      }
    };
  };

  utils.rewriteRequest = function (req, res, next) {
    if (rules.length) {
      if (!rules.some(utils.dispatcher(req, res))) {
        next();
      }
    } else {
      next()
    }
  };