Add cookie and session support to Dropbox file browser example.

app-configure-block.js

app.configure(function() {
  app.use(express.logger());
  app.use(express.bodyDecoder());
  app.use(express.cookieDecoder()); // Cookie-decoding.
  app.use(express.session());       // Session-handling.
});

app-sessions-final.js

var sys = require('sys'),
    http = require('http'),
    OAuth = require('oauth').OAuth,
    DropboxClient = require('dropbox').DropboxClient,
    express = require('express'),
    app = express.createServer();

// Initialize OAuth object.
var API_URI = 'http://api.dropbox.com/',
    API_VERSION = '0',
    consumer_key = 'your_consumer_key',
    consumer_secret = 'your_consumer_secret',
    oauth = new OAuth(
      API_URI + API_VERSION + '/oauth/request_token',
      API_URI + API_VERSION + '/oauth/access_token',
      consumer_key, consumer_secret,
      '1.0', null, 'HMAC-SHA1');

app.configure(function() {
  app.use(express.logger());
  app.use(express.bodyDecoder());
  app.use(express.cookieDecoder());
  app.use(express.session());
});

// CSS file request.
app.get('/*.css', function(req, res) {
  res.render(req.params[0] + '.sass', { layout: false });
});

// Login page.
app.get('/', function(req, res) {
  res.render('login.jade', {
    locals: {
      title: 'Dropbox File Browser'
    }
  });
});

// Dropbox credential processing.
app.post('/process_creds', function(req, res) {
  // Get access token.
  var client = http.createClient(80, 'www.dropbox.com'),
      request = client.request('GET', API_URI + API_VERSION +
                               '/token?oauth_consumer_key=' + consumer_key +
                               '&email=' + req.body.email +
                               '&password=' + req.body.password,
                               {'host': 'www.api.dropbox.com'});
  request.end();

  // Upon response, extract access token/secret and redirect to file_browser.
  request.on('response', function(token_res) {
    token_res.setEncoding('utf8');
    token_res.on('data', function(chunk) {
      var token_res = JSON.parse(chunk),
          access_token = token_res['token'],
          access_token_secret = token_res['secret'];
      req.session.dropbox = new DropboxClient(oauth, access_token,
                                              access_token_secret);

      res.redirect('/file_browser');
    });
  });
});

// File browser page.
app.get('/file_browser(/*)?', function(req, res) {
  // Fetch target metadata and render the page.
  if (req.session.dropbox) {
    req.session.dropbox.getMetadata(req.params[1] || '',
                                    function(err, metadata) {
      if (err) console.log('Error: ' + sys.inspect(err));
      else {
        // NOTE: Use this to strip leading path(s): str.replace(/^.*\//g, '');
        res.render('file_browser.jade', {
          locals: {
            title: 'Dropbox File Browser',
            current_dir: (metadata.path.length > 0) ? metadata.path : 'root',
            items: metadata.contents
          }
        });
      }
    });
  } else res.redirect('home');
});

app.listen(3000);

file_browser-route.js

// File browser page.                                                                   
app.get('/file_browser(/*)?', function(req, res) {
  // Fetch target metadata and render the page.                                         
  if (req.session.dropbox) {
    req.session.dropbox.getMetadata(req.params[1] || '',
                                    function(err, metadata) {
      if (err) console.log('Error: ' + sys.inspect(err));
      else {
        // NOTE: Use this to strip leading path(s): str.replace(/^.*\//g, '');          
        res.render('file_browser.jade', {
          locals: {
            title: 'Dropbox File Browser',
            current_dir: (metadata.path.length > 0) ? metadata.path : 'root',
            items: metadata.contents
          }
        });
      }
    });
  } else res.redirect('home');
});

process_creds.js

// Upon response, extract access token/secret and redirect to file_browser.
request.on('response', function(token_res) {
  token_res.setEncoding('utf8');
  token_res.on('data', function(chunk) {
    var token_res = JSON.parse(chunk),
        access_token = token_res['token'],
        access_token_secret = token_res['secret'];
    req.session.dropbox = new DropboxClient(oauth, access_token,
                                            access_token_secret);
    res.redirect('/file_browser');
  });
});

remove-persistant-var-init.js

// Set up persistent variables.
// Delete this section or comment out the following line.
//var access_token = '', access_token_secret = '', dropbox = null;