Addressing review comments.

* list_dirs and get_dir_model added to base NBM class.
* Calling of list_dirs moved to handler.
* type=notebook added to notebook model.

IPython/html/services/notebooks/filenbmanager.py

@@ -159,12 +159,17 b' class FileNotebookManager(NotebookManager):'
         """List the directories for a given API style path."""
         path = path.strip('/')
         os_path = self.get_os_path('', path)
+        if not os.path.isdir(os_path):
+            raise web.HTTPError(404, u'diretory does not exist: %r' % os_path)
         dir_names = os.listdir(os_path)
         dirs = []
         for name in dir_names:
             os_path = self.get_os_path(name, path)
             if os.path.isdir(os_path) and not name.startswith('.'):
+                try:
                 model = self.get_dir_model(name, path)
+                except IOError:
+                    pass
                 dirs.append(model)
         dirs = sorted(dirs, key=lambda item: item['name'])
         return dirs
@@ -206,16 +211,8 b' class FileNotebookManager(NotebookManager):'
         """
         path = path.strip('/')
         notebook_names = self.get_notebook_names(path)
-        index = []
-        notebooks = []
-        for name in notebook_names:
-            model = self.get_notebook_model(name, path, content=False)
-            if name.lower() == 'index.ipynb':
-                index.append(model)
-            else:
-                notebooks.append(model)
+        notebooks = [self.get_notebook_model(name, path, content=False) for name in notebook_names]
         notebooks = sorted(notebooks, key=lambda item: item['name'])
-        notebooks = index + self.list_dirs(path) + notebooks
         return notebooks
 
     def get_notebook_model(self, name, path='', content=True):
@@ -248,6 +245,7 b' class FileNotebookManager(NotebookManager):'
         model['path'] = path
         model['last_modified'] = last_modified
         model['created'] = created
+        model['type'] = 'notebook'
         if content:
             with io.open(os_path, 'r', encoding='utf-8') as f:
                 try:

IPython/html/services/notebooks/handlers.py

@@ -69,8 +69,18 b' class NotebookHandler(IPythonHandler):'
         nbm = self.notebook_manager
         # Check to see if a notebook name was given
         if name is None:
-            # List notebooks in 'path'
-            notebooks = nbm.list_notebooks(path)
+            # TODO: Remove this after we create the contents web service and directories are
+            # no longer listed by the notebook web service. This should only handle notebooks
+            # and not directories.
+            dirs = nbm.list_dirs(path)
+            notebooks = []
+            index = []
+            for nb in nbm.list_notebooks(path):
+                if nb['name'].lower() == 'index.ipynb':
+                    index.append(nb)
+                else:
+                    notebooks.append(nb)
+            notebooks = index + dirs + notebooks
             self.finish(json.dumps(notebooks, default=date_default))
             return
         # get and return notebook representation

IPython/html/services/notebooks/nbmanager.py

@@ -112,6 +112,26 b' class NotebookManager(LoggingConfigurable):'
         """
         return basename
 
+    # TODO: Remove this after we create the contents web service and directories are
+    # no longer listed by the notebook web service.
+    def list_dirs(self, path):
+        """List the directory models for a given API style path."""
+        raise NotImplementedError('must be implemented in a subclass')
+
+    # TODO: Remove this after we create the contents web service and directories are
+    # no longer listed by the notebook web service.
+    def get_dir_model(self, name, path=''):
+        """Get the directory model given a directory name and its API style path.
+        
+        The keys in the model should be:
+        * name
+        * path
+        * last_modified
+        * created
+        * type='directory'
+        """
+        raise NotImplementedError('must be implemented in a subclass')
+
     def list_notebooks(self, path=''):
         """Return a list of notebook dicts without content.
 

IPython/html/services/notebooks/tests/test_notebooks_api.py

@@ -24,7 +24,7 b' from IPython.utils.data import uniq_stable'
 # TODO: Remove this after we create the contents web service and directories are
 # no longer listed by the notebook web service.
 def notebooks_only(nb_list):
-    return [nb for nb in nb_list if 'type' not in nb]
+    return [nb for nb in nb_list if nb['type']=='notebook']
 
 
 class NBAPI(object):