WebFund 2013F: Tutorial 9

In this tutorial you will be modifying adventure-ajax-demo, an updated version of Simple Adventure that now uses asynchronous background requests (AJAX) to navigate between rooms and update the page.

First, grab the code, either with modules or without. Then unzip it and get it running as usual. (If you download the version with modules, you shouldn't need to run npm install.)

Do the following:

• Create a room, the Holodeck, which is just connected to sick bay.
• Get to the secret room by editing and re-sending a post request.
• Modify the server code so that attempts to get to non-existent rooms instead send you to the Void.
• Modify the server code so that if the password "openSesame" is included in the post request, it allows users to enter the secret room. If users give the wrong password or no password at all, they should get redirected to the void.
• [BONUS] Modify the server so only allows users to exit using valid exits for the current room.

Code

package.json

{
  "name": "application-name",
  "version": "0.0.1",
  "private": true,
  "scripts": {
    "start": "node app.js"
  },
  "dependencies": {
    "express": "3.4.0",
    "jade": "*",
    "stylus": "*",
    "validator": "*"
   }
}

app.js

/**
 * Module dependencies.
 */

var express = require('express');
var routes = require('./routes');
var http = require('http');
var path = require('path');

var app = express();

// all environments
app.set('port', process.env.PORT || 3000);
app.set('views', __dirname + '/views');
app.set('view engine', 'jade');
app.use(express.favicon());
app.use(express.logger('dev'));
app.use(express.bodyParser());
app.use(express.methodOverride());
app.use(express.cookieParser('COMP2406 rules!'));
app.use(express.session());
app.use(app.router);
app.use(require('stylus').middleware(__dirname + '/public'));
app.use(express.static(path.join(__dirname, 'public')));


// development only
if ('development' == app.get('env')) {
  app.use(express.errorHandler());
}

app.get('/', routes.index);
app.get('/game', routes.game);
app.get('/getContents', routes.getContents);
app.post('/start', routes.start);
app.post('/quit', routes.quit);
app.post('/doAction', routes.doAction);

http.createServer(app).listen(app.get('port'), function(){
    console.log('Express server listening on port ' + app.get('port'));
});

routes/index.js

var sanitize = require('validator').sanitize;
var rooms = require('../rooms.js').rooms;

function index(req, res) {
    if (req.session.player) {
        res.redirect("/game");
    } else {
	res.render('index', { title: 'COMP 2406 Adventure Demo', 
			      error: req.query.error });
    }
}

function start(req, res) {
    var player = req.body.player;
    // Sanitize the player name as it may be displayed
    req.session.player = sanitize(player).escape();
    req.session.currentRoom = "bridge"; // We start on the bridge
    res.redirect("/game")
}

function quit(req, res) {
    req.session.destroy(function(err){
        if(err){
            console.log("Error: %s", err);
        }
    });
    res.redirect("/");
}

function game(req, res) {
    if (req.session.player) {
	res.render("room.jade", {title: "Adventure Demo"});
    } else {
        res.redirect("/");
    }
}

function doAction(req, res) {
    var action = req.body.action;
    var room = req.body.room;

    if (action === "move") {
	req.session.currentRoom = room;
	res.send("Success");
    } else {
	res.send("Error: InvalidAction");
    }
}

function getContents(req, res) {    
    res.send(rooms[req.session.currentRoom]);
}

exports.index = index;
exports.start = start;
exports.quit = quit;
exports.game = game;
exports.doAction = doAction;
exports.getContents = getContents;

public/javascripts/adventure.js

// adventure.js
// client-side code for adventure AJAX demo

(function() {  // setup local scope

    var getRoom = function() {
	$.getJSON("/getContents", function(room) {
	    var exits;
	    $('#title').replaceWith('<h1 id="title">'+room.title+'</h1>');
	    $('#description').replaceWith('<p id="description">' +
					  room.description + '</p>');
	    $('.exits').remove();
	    room.roomExits.forEach(function(theExit) {
		$('#exitList').append(
		    '<button type="button" id="' + theExit +
			'" class="btn btn-default exits">'
			+ theExit + '</button>');
		$('#'+theExit).on('click', function() {
		    $.post("/doAction", {action: "move",
					 room: theExit});
		    getRoom();
		});
	    });
	});	
    }

    $(window).load(getRoom());

})(); // finish setting up local scope (call function defined)

rooms.js

// rooms.js

var rooms = {
    bridge: {
	title: "Bridge",
	description: "You are on the Bridge.  There are big comfy chairs and a big screen here.",
	roomExits: ['sickbay'],
    },
    
    engineering: {
	title: "Engineering",
	description: "You are in Engineering.  There are lots of funny instruments, many smaller screens, and kind of uncomfortable chairs.",
	roomExits: ['sickbay'],
    },

    sickbay: {
	title: "Sickbay",
	description: "You are in Sickbay.  It is in the center of the ship, the safest place there is.  There are lots of comfy beds here and blinky lights.",
	roomExits: ['engineering','bridge'],
    },

    secret: {
	title: "Secret Room",
	description: "This is a secret room.  How did you get here?",
	roomExits: ['engineering', 'sickbay', 'bridge'],
    },

    TheVoid: {
	title: "The Void",
	description: "You are in the Void.  This is the fate of all cheaters.",
	roomExits: ['TheVoid'],
    },
};

exports.rooms = rooms;

views/index.jade

extends layout

block content
  h1= title
  p Welcome to the #{title}
  - if(error)
    div.alert-error #{error}
  p Please choose your player name
  div
    form(action="/start", method="post")
        div.control-group.input-append
            input(type="text", name="player")
            label.add-on(for="player") Player Name
        button(type="submit") Start

views/layout.jade

doctype 5
html
  head
    title= title
    script(src='/libs/jquery/jquery.min.js')
    link(rel='stylesheet', href='/libs/bootstrap/css/bootstrap.min.css')
    link(rel='stylesheet', href='/stylesheets/style.css')
  body
    block content