qewd/lib/master-express.js

/*

 ----------------------------------------------------------------------------
 | qewd: Quick and Easy Web Development                                     |
 |                                                                          |
 | Copyright (c) 2017-19 M/Gateway Developments Ltd,                        |
 | Redhill, Surrey UK.                                                      |
 | All rights reserved.                                                     |
 |                                                                          |
 | http://www.mgateway.com                                                  |
 | Email: rtweed@mgateway.com                                               |
 |                                                                          |
 |                                                                          |
 | Licensed under the Apache License, Version 2.0 (the "License");          |
 | you may not use this file except in compliance with the License.         |
 | You may obtain a copy of the License at                                  |
 |                                                                          |
 |     http://www.apache.org/licenses/LICENSE-2.0                           |
 |                                                                          |
 | Unless required by applicable law or agreed to in writing, software      |
 | distributed under the License is distributed on an "AS IS" BASIS,        |
 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
 | See the License for the specific language governing permissions and      |
 |  limitations under the License.                                          |
 ----------------------------------------------------------------------------

  27 March 2019

   Thanks to:
    Ward De Backer for:
     - body-parser enhancement
     - beforeRouter and afterRouter enhancement                

*/

var express = require('express');
var bodyParser;
var app = express();

var qx;
var q;

function configure(config, routes, qOper8, qExt) {
  qx = qExt;
  q = qOper8;

  // if user instantiates his/her own bodyParser module, use it
  //  Note: user must then also define the app.use express middleware to use it
  if (config.bodyParser) {
    console.log('Custom Body Parser has been loaded');
    bodyParser = config.bodyParser;
  }
  else {
    bodyParser = require('body-parser');
    app.use(bodyParser.json());
    // note: config.webServer will be 'express'
  }

  if (config.qewd_up) {
    // augment req with method to allow optional additional forwarding of messages
    // in onWSRequest handler - one-way fire and forget messages
    //  eg for recording audit trails
    //   Note: always a POST

    var sendFireAndForgetMsg = function(req, params) {

      var _req = {
        originalUrl: params.url,
        method: 'POST',
        headers: req.headers,
        body: params.body
      };

      // dummy res object to fool qx.handleMessage and bypass normal response
      //  handling - we don't want the response to go back to client

      var _res = {
        set: function() {return false},
        status: function() {
          return this;
        },
        send: function(obj) {
          return false;
        },
        locals: {}
      };
      qx.handleMessage(_req, _res);
    };

    app.use(function(req, res, next) {
      req.sendFireAndForgetMsg = sendFireAndForgetMsg;
      return next();
    });

  }

  // if user defines addMiddleware method, give them complete control!
  if (config.addMiddleware) {
    config.addMiddleware(bodyParser, app, q, qx, config);
  }
  else if (config.addMiddlewareUp) {
    config.addMiddlewareUp.call(q, bodyParser, app, qx.router, config, qx);
  }

  app.post('/ajax', function(req, res) {
    console.log('/ajax body: ' + JSON.stringify(req.body));
    req.headers.qewd = 'ajax';
    qx.handleMessage(req, res);
  });

  console.log('webServerRootPath = ' + config.webServerRootPath);
  if (config.cors) {
    app.use('/', function (req, res, next) {
      //res.header('Access-Control-Allow-Origin', '*');
      //res.header('Access-Control-Allow-Headers', 'Origin, X-Requested-With, Content-Type, Accept');

      res.header('Access-Control-Allow-Credentials', 'true');
      res.header('Access-Control-Allow-Headers', 'DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Authorization');
      res.header('Access-Control-Allow-Methods', 'GET, PUT, DELETE, POST, OPTIONS');
      res.header('Access-Control-Allow-Origin', '*');
      next();
    });
  }
  app.use('/', express.static(config.webServerRootPath))

  if (routes) {
    routes.forEach(function(route) {

      // Ward DeBacker: September 2017
      // create (variable) arguments array to pass to app.use()

      var args = [route.path];
      // add array with custom middleware to add before qx.router is called (if present)

      if (route.beforeRouter && Array.isArray(route.beforeRouter)) args = args.concat(route.beforeRouter);

      // in case route.afterRouter is present, nextCallback must be set to true
      // to prevent handleMessage() sending reponse. User will have done this

      var options = {
        nextCallback: route.afterRouter ? true : false
      };
      args = args.concat([qx.router(options)]);

      // add array with custom middleware to add after qx.router is called (if present)

      if (route.afterRouter && Array.isArray(route.afterRouter)) args = args.concat(route.afterRouter);

      // define the Express route by calling app.use()

      app.use.apply(app, args); // allow user to define custom middleware for each route
      //app.use(path, qx.router());
      console.log('route ' + route.path + ' will be handled by qx.router');
    });
  }
  return app;
}

module.exports = configure;