app-context-express

app-context-express

express initializer for app-context

The express initializer provides structure to your express server initialization and removes boilerplate.

Usage

Using this initializer in your context file will automatically install it.

After this initializer, the express app will be attached to APP.express, the HTTP server to APP.httpServer, and the HTTPS server to APP.httpsServer.

module.exports = function() {
  this.runlevel('running')
    // use all defaults
    .use('express')

    // listen on port 8000 and execute scripts server/initialize.js, server/middleware.js, server/router.js
    .use('express', {
      port: 8000,
      root: 'server'
    })

    // use port and ssl settings from config
    // specify custom scripts to execute before listening, which are located in the server directory
    .use('express', {
      port: '$server.port',
      ssl: '$server.ssl',
      root: 'server',
      execute: [
        'middleware',
        'internal-router',
        'external-router'
      ]
    })
};

Options

root - directory to find execute scripts in (defaults to the project root)

execute - string or array of scripts to run, in order, to setup the express server (defaults to initialize, middleware, router)

port - port for the HTTP server to listen on (defaults to process.env.PORT or 3000)

SSL Options

An HTTPS server will be started if you include either a key and cert, or a pfx file.

ssl.port - port for the HTTPS server to listen on (defaults to process.env.HTTPS_PORT or port + 1)

ssl.key, ssl.cert - path of the key and certificate files relative to project root

ssl.pfx - path of the pfx file relative to project root

Discussion

The express initializer takes 3 distinct steps.

• Create express app and assign it to context.express (or APP.express).
• Load and execute the scripts listed in the execute option in order, passing the express app and current context into each script. Missing scripts will be ignored.
• Create HTTP and optionally HTTPS servers and tell each to listen on their respective ports.

Steps 1 and 3 are simple enough. Step 2 needs a little more detail. This is where the main separation and structure is created, by separating the steps in which you configure your server.

Each script in the execute list is expected to export a method that takes an express app and optionally the current context. The app is the app created by the initializer and the context is the current app-context instance (also accessible via APP).

module.exports = function(app, context) {

};

You can decide which scripts to execute to customize your process by specifying either a single filename or an array of filenames.

The default execute behavior

By default a preset list of scripts will be used. These are initialize, middleware, and router. Additionally, if no middleware file is found, a default set of middleware will be configured for you. The default middleware.js file is:

module.exports = function(app, context) {
  var morgan = require('morgan');
  var bodyParser = require('body-parser');
  var methodOverride = require('method-override');

  app.use(morgan('dev'));
  app.use(bodyParser.urlencoded({extended: false}));
  app.use(bodyParser.json());
  app.use(methodOverride('X-HTTP-Method-Override'));
  app.use(methodOverride('_method'));
  app.use(methodOverride(function(req, res) {
    if (req.body && typeof(req.body) === 'object' && '_method' in req.body) {
      var method = req.body._method;
      delete req.body._method;
      return method;
    }
  }));
};