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)