diff --git a/hw6/Claudio_Maggioni/app.js b/hw6/Claudio_Maggioni/app.js
index b9367aa..0ccd0e7 100644
--- a/hw6/Claudio_Maggioni/app.js
+++ b/hw6/Claudio_Maggioni/app.js
@@ -39,7 +39,8 @@ app.use(express.static('public'));
 // Initialize routers here
 const routers = require('./routes/routers');
 app.use('/', routers.root);
-app.use('/favorites', routers.favourites_db);
+// app.use('/favorites', routers.favourites_db);
+app.use('/favorites', routers.favourites_db_promises);
 app.use('/bookmarked', routers.bookmarked);
 
 module.exports = app;
diff --git a/hw6/Claudio_Maggioni/routes/favourites_db/router.js b/hw6/Claudio_Maggioni/routes/favourites_db/router.js
index efc3cd9..cb1d70b 100644
--- a/hw6/Claudio_Maggioni/routes/favourites_db/router.js
+++ b/hw6/Claudio_Maggioni/routes/favourites_db/router.js
@@ -7,7 +7,17 @@ const express = require('express');
 const router = express.Router();
 const mongoose = require('mongoose');
 const Favorite = mongoose.model('Favorite');
-const { error, renderFav } = require('../utils');
+const { error, renderFav, parseId, notFound } = require('../utils');
+
+function findAndRender(filter, req, res) {
+  Favorite.find(filter, (err, favs) => {
+    if (err) {
+      return error(err, res);
+    }
+
+    renderFav(req, res, favs);
+  });
+}
 
 router.post('/', (req, res) => {
   if (!req.body.name || !req.body.dataURL) {
@@ -25,6 +35,8 @@ router.post('/', (req, res) => {
 
   if (req.body._id) {
     favourite._id = req.body._id;
+  } else {
+    favourite._id = mongoose.Types.ObjectId();
   }
 
   favourite.save((err, fav) => {
@@ -39,13 +51,7 @@ router.post('/', (req, res) => {
 });
 
 router.get('/', (req, res) => {
-  Favorite.find({}, (err, favs) => {
-    if (err) {
-      return error(err, res);
-    }
-
-    renderFav(req, res, favs);
-  });
+  findAndRender({}, req, res);
 });
 
 router.get('/search', (req, res) => {
@@ -53,25 +59,20 @@ router.get('/search', (req, res) => {
   delete filter['dataURL'];
   delete filter['_method'];
 
-  Favorite.find(filter, (err, favs) => {
-    if (err) {
-      return error(err, res);
-    }
-
-    renderFav(req, res, favs);
-  });
+  findAndRender(filter, req, res);
 });
 
 router.get('/:id', (req, res) => {
-  Favorite.findById(req.params.id, (err, fav) => {
+  Favorite.findById(parseId(req), (err, fav) => {
     if (err) {
       return error(err, res);
-    } else if (!fav) {
-      res.writeHead(404, {'Content-Type': 'text/plain'});
-      res.end('Not found');
-    } else {
-      renderFav(req, res, fav, false);
     }
+
+    if (notFound(fav, res)) {
+      return;
+    }
+
+    renderFav(req, res, fav, false);
   });
 });
 
@@ -90,10 +91,10 @@ function handleUpdate(partial = false) {
     }
 
     if (req.body.bookmarked !== undefined) {
-      edit.bookmarked = !!req.body.bookmarked;
+      edit.bookmarked = req.body.bookmarked;
     }
 
-    Favorite.findByIdAndUpdate(req.params.id, { $set: edit }, {
+    Favorite.findByIdAndUpdate(parseId(req), { $set: edit }, {
       new: true,
       upsert: true,
       setDefaultsOnInsert: true,
@@ -112,18 +113,16 @@ function handleUpdate(partial = false) {
 }
 
 router.put('/:id', handleUpdate());
+
 router.patch('/:id', handleUpdate(true));
 
-
 router.delete('/:id', (req, res) => {
-  Favorite.findByIdAndDelete(req.params.id, (err, fav) => {
+  Favorite.findByIdAndDelete(parseId(req), (err, fav) => {
     if (err) {
       return error(err, res);
     }
 
-    if (fav == null) {
-      res.writeHead(404, { 'Content-Type': 'text/plain' });
-      res.end('Favourite not found');
+    if (notFound(fav, res)) {
       return;
     }
 
@@ -136,20 +135,18 @@ router.delete('/:id', (req, res) => {
 });
 
 router.put('/:id/bookmarked', (req, res) => {
-  Favorite.findByIdAndUpdate(req.params.id, {
-    $set: { bookmarked: !!req.body.bookmarked }
+  Favorite.findByIdAndUpdate(parseId(req), {
+    $set: { bookmarked: req.body.bookmarked }
   }, { new: true }, (err, fav) => {
-    if (false) {
-      res.writeHead(404, { 'Content-Type': 'text/plain' });
-      res.end('Favourite to bookmark not found');
-    } else if (!req.body.bookmarked) {
+    if (notFound(fav, res)) {
+      return;
+    }
+
+    if (!req.body.bookmarked) {
       res.writeHead(400, { 'Content-Type': 'text/plain' });
       res.end('Bad PUT bookmark form parameters');
     } else {
-      res.format({
-        html: () => renderFav(req, res, fav, false),
-        json: () => res.json(fav)
-      });
+      renderFav(req, res, fav, false);
     }
   });
 });
diff --git a/hw6/Claudio_Maggioni/routes/favourites_db_promises/router.js b/hw6/Claudio_Maggioni/routes/favourites_db_promises/router.js
new file mode 100644
index 0000000..3139d2f
--- /dev/null
+++ b/hw6/Claudio_Maggioni/routes/favourites_db_promises/router.js
@@ -0,0 +1,136 @@
+/** @module root/router */
+'use strict';
+// vim: set ts=2 sw=2 et tw=80:
+
+const fs = require('fs');
+const express = require('express');
+const router = express.Router();
+
+const mongoose = require('mongoose');
+const Favorite = mongoose.model('Favorite');
+
+const { error, catchErrs, renderFav, parseId, notFound } = require('../utils');
+
+function findAndRender(filter, req, res) {
+  catchErrs(Favorite.find(filter), res).then(favs => {
+    renderFav(req, res, favs);
+  });
+}
+
+router.post('/', (req, res) => {
+  if (!req.body.name || !req.body.dataURL) {
+    res.writeHead(400, { 'Content-Type': 'text/plain' });
+    res.end('Bad create form parameters');
+    return;
+  }
+
+  const data = {
+    name: req.body.name,
+    dataURL: req.body.dataURL,
+    bookmarked: req.body.bookmarked,
+  };
+  const favourite = new Favorite(data);
+
+  if (req.body._id) {
+    favourite._id = req.body._id;
+  } else {
+    favourite._id = mongoose.Types.ObjectId();
+  }
+
+  catchErrs(favourite.save(), res).then(fav => {
+    res.status = 201;
+    const _id = fav._id;
+    renderFav(req, res, Object.assign({ _id }, data), false);
+  });
+});
+
+router.get('/', (req, res) => {
+  findAndRender({}, req, res);
+});
+
+router.get('/search', (req, res) => {
+  const filter = Object.assign({}, req.query);
+  delete filter['dataURL'];
+  delete filter['_method'];
+
+  findAndRender(filter, req, res);
+});
+
+router.get('/:id', (req, res) => {
+  catchErrs(Favorite.findById(parseId(req)), res).then(fav => {
+    if (notFound(fav, res)) {
+      return;
+    }
+
+    renderFav(req, res, fav, false);
+  });
+});
+
+function handleUpdate(partial = false) {
+  return (req, res) => {
+    const edit = {};
+    for (const key of ['dataURL', 'name']) {
+      if (req.body[key]) {
+        edit[key] = req.body[key];
+      } else if (!partial) {
+        res.writeHead(400, { 'Content-Type': 'text/plain' });
+        res.end('Bad PUT form parameters');
+        return;
+      }
+    }
+
+    if (req.body.bookmarked !== undefined) {
+      edit.bookmarked = req.body.bookmarked;
+    }
+
+    catchErrs(Favorite.findByIdAndUpdate(parseId(req), { $set: edit }, {
+      new: true,
+      upsert: true,
+      setDefaultsOnInsert: true,
+    }), res).then(fav => {
+      console.log(arguments);
+
+      // FIXME: return 201 on creation
+      res.status = 200;
+      renderFav(req, res, fav, false);
+    });
+  };
+}
+
+router.put('/:id', handleUpdate());
+
+router.patch('/:id', handleUpdate(true));
+
+router.delete('/:id', (req, res) => {
+  catchErrs(Favorite.findByIdAndDelete(parseId(req)), res).then(fav => {
+    if (notFound(fav, res)) {
+      return;
+    }
+
+    res.format({
+      json: () => res.writeHead(204),
+      html: () => res.writeHead(302, { 'Location': '/favorites' })
+    });
+    res.end();
+  });
+});
+
+router.put('/:id/bookmarked', (req, res) => {
+  catchErrs(Favorite.findByIdAndUpdate(parseId(req), {
+    $set: { bookmarked: req.body.bookmarked }
+  }, { new: true }), res).then(fav => {
+    if (notFound(fav, res)) {
+      return;
+    }
+
+    if (!req.body.bookmarked) {
+      res.writeHead(400, { 'Content-Type': 'text/plain' });
+      res.end('Bad PUT bookmark form parameters');
+    } else {
+      renderFav(req, res, fav, false);
+    }
+  });
+});
+
+/** router for /root */
+module.exports = router;
diff --git a/hw6/Claudio_Maggioni/routes/utils.js b/hw6/Claudio_Maggioni/routes/utils.js
index f62be29..215c1d7 100644
--- a/hw6/Claudio_Maggioni/routes/utils.js
+++ b/hw6/Claudio_Maggioni/routes/utils.js
@@ -1,8 +1,16 @@
+// vim: set ts=2 sw=2 et tw=80:
+
+const mongoose = require('mongoose');
+
+function catchErrs(promise, res) {
+  return promise.catch(err => error(err, res));
+}
+
 function error(err, res) {
   console.error(err);
   res.status = 500;
   res.format({
-    json: () => res.json({error: err}),
+    json: () => res.json({ error: err }),
     html: () => res.render('500.dust', { err: JSON.stringify(err, null, 2) }),
   });
   res.end();
@@ -18,15 +26,16 @@ function renderFav(req, res, favs, list = true) {
     }
   };
 
-  if (list) {
-    favs = favs.map(makeTestsPass);
-  } else {
-    favs = makeTestsPass(favs);
-  }
-
   if (req.accepts('html')) {
-    res.render(favs ? 'favourites.dust' : 'favourite.dust', list ? { favs } : favs);
+    res.render(list ? 'favourites.dust' : 'favourite.dust',
+      list ? { favs } : favs);
   } else if (req.accepts('json')) {
+    if (list) {
+      favs = favs.map(makeTestsPass);
+    } else {
+      favs = makeTestsPass(favs);
+    }
+
     res.json(favs);
   } else {
     res.writeHead(406);
@@ -34,6 +43,22 @@ function renderFav(req, res, favs, list = true) {
   }
 }
 
-module.exports = { error, renderFav };
+function parseId(req) {
+  if (typeof req.params.id === 'string' && req.params.id.length == 24) {
+    return mongoose.Types.ObjectId(req.params.id);
+  } else {
+    return req.params.id;
+  }
+}
+
+function notFound(e, res) {
+  if (e == null) {
+    res.writeHead(404, {'Content-Type': 'text/plain'});
+    res.end('Not found');
+    return true;
+  } else return false;
+}
+
+module.exports = { error, renderFav, catchErrs, parseId, notFound };
 
 
diff --git a/hw6/Claudio_Maggioni/views/favourite_partial.dust b/hw6/Claudio_Maggioni/views/favourite_partial.dust
index a431d83..703a421 100644
--- a/hw6/Claudio_Maggioni/views/favourite_partial.dust
+++ b/hw6/Claudio_Maggioni/views/favourite_partial.dust
@@ -16,13 +16,13 @@
   <input type="text" name="name" placeholder="Name" value="{name}"><br>
   <button>Update</button><br>
   <button formaction="/favorites/{_id}?_method=DELETE">Delete</button><br>
-  {?b}
+  {?bookmarked}
   <button name="bookmarked" value="false"
     formaction="/favorites/{_id}/bookmarked?_method=PUT">Remove bookmark</button>
   {:else}
   <button name="bookmarked" value="true"
     formaction="/favorites/{_id}/bookmarked?_method=PUT">Add bookmark</button>
-  {/b}
+  {/bookmarked}
 </form>
 <a href="/favorites">Favourites list</a>
 {/details}
diff --git a/hw6/Claudio_Maggioni/views/favourites.dust b/hw6/Claudio_Maggioni/views/favourites.dust
index 271d285..b8dc167 100644
--- a/hw6/Claudio_Maggioni/views/favourites.dust
+++ b/hw6/Claudio_Maggioni/views/favourites.dust
@@ -17,7 +17,7 @@
     {/bookmarked}
     {#favs}
     <div>
-      {>"favourite_partial" name=name dataURL=dataURL _id=_id b=b details="true" /}
+      {>"favourite_partial" name=name dataURL=dataURL _id=_id bookmarked=bookmarked details="true" /}
     </div>
     {:else}
     <strong>No favourites.</strong>
diff --git a/hw6/Claudio_Maggioni/views/index.dust b/hw6/Claudio_Maggioni/views/index.dust
index 02c3344..e7febfa 100644
--- a/hw6/Claudio_Maggioni/views/index.dust
+++ b/hw6/Claudio_Maggioni/views/index.dust
@@ -28,7 +28,7 @@
     <h2>Favourites</h2>
     <div id="favourites">
       {#favs}
-      {>"favourite_partial" name=name dataURL=dataURL _id=_id b=b details="true" /}
+      {>"favourite_partial" name=name dataURL=dataURL _id=_id bookmarked=bookmarked details="true" /}
       {/favs}
     </div>
     <script src="scripts/brushes.js"></script>