Connect middleware to handle web based OAuth authorization

lib/dropbox-node.js

@@ -3,7 +3,8 @@ var querystring = require('querystring')
   , stringifyParams = require('./util/stringify-params')
   , OAuth = require('oauth').OAuth
   , API_URI = 'http://api.dropbox.com/0'
-  , CONTENT_API_URI = 'https://api-content.dropbox.com/0';
+  , CONTENT_API_URI = 'https://api-content.dropbox.com/0'
+  , AUTHORIZE_URI = 'http://www.dropbox.com/0/oauth/authorize';
 
 
 // Returns a Dropbox Client, through which API calls can be made.
@@ -42,6 +43,88 @@ DropboxClient.prototype.getAccessToken = function(email, pwd, cb) {
                  });
 }
 
+// Connect middleware to provide OAuth based authorization to Dropbox
+// on the specified path. Requires connect-session middleware.
+// After successful authorization, user's session will contain
+// access_token and access_token_secret
+DropboxClient.prototype.login = function(mount, success) {
+  var self = this
+    , url = require('url')
+    , mount = mount || '/dbauth';
+
+  return function handle(req, res, next) {
+    var path = url.parse(req.url, true);
+
+    // Only handle requests to the exact path
+    if(path.pathname !== mount) return next();
+
+    // Set the oauth_callback based on this request if we don't have it
+    if(!self.oauth._authorize_callback) {
+      var scheme = req.socket.secure ? "https://" : "http://"
+        , callback_uri = url.parse(scheme + req.headers.host + req.url, true);
+      self.oauth._authorize_callback = callback_uri.href;
+    }
+
+    // Get the info in the user's session
+    var dbauth = req.session.dbauth;
+
+    // User is already authenticated, but in the wrong place
+    if(dbauth && dbauth.access_token_secret) {
+      res.writeHead(302, {'Location': success || '/'});
+      res.end();
+      return;
+
+    // User is returning from Dropbox with oauth_token
+    } else if(path.query && path.query.oauth_token && path.query.uid
+              && dbauth && dbauth.oauth_token_secret) {
+      self.oauth.getOAuthAccessToken(
+              path.query.oauth_token, dbauth.oauth_token_secret
+            , path.query.oauth_verifier
+            , function(error, access_token, access_token_secret, params) {
+              if(error) {
+                return next(error);
+              } else {
+                req.session.dbauth = {
+                  uid: path.query.uid,
+                  access_token: access_token,
+                  access_token_secret: access_token_secret
+                };
+                res.writeHead(302, {'Location': success || '/'});
+                res.end();
+                return;
+              }
+            })
+    // Begin OAuth transaction if we have no session or access_token_secret
+    } else if(!(dbauth && dbauth.access_token_secret)) {
+      self.oauth.getOAuthRequestToken(
+              function(error, oauth_token, oauth_token_secret, params) {
+                if(error) {
+                  return next(error);
+                } else {
+                  req.session.dbauth = {
+                    oauth_token: oauth_token,
+                    oauth_token_secret: oauth_token_secret
+                  };
+                  res.writeHead(302, {
+                    'Location': AUTHORIZE_URI + '?'
+                      + stringifyParams({
+                        oauth_token: oauth_token,
+                        oauth_callback: self.oauth._authorize_callback
+                      })
+                  });
+                  res.end();
+                  return;
+                }
+              });
+    // Invalid data in session, clear session data and restart process
+    } else {
+      delete req.session.dbauth;
+      res.writeHead(302, {'Location': mount});
+      res.end();
+      return;
+    }
+  }
+}
 
 // Retrieves information about the user's account as a JSON response.
 DropboxClient.prototype.getAccountInfo = function(optargs, cb) {