Adding proper breadcrumb support.

IPython/html/templates/tree.html

@@ -47,8 +47,9 b' data-base-kernel-url="{{base_kernel_url}}"'
           <div id="notebook_list_header" class="row-fluid list_header">
               <div id="project_name">
                 <ul class="breadcrumb">
-                    {% for component in tree_url_path.strip('/').split('/') %}
-                        <li>{{component}} <span>/</span></li>
+                    <li><span><a href="{{breadcrumbs[0][0]}}">/</a></span></li>
+                    {% for crumb in breadcrumbs[1:] %}
+                        <li><a href="{{crumb[0]}}">{{crumb[1]}}</a> <span>/</span></li>
                     {% endfor %}
                 </ul>
               </div>

IPython/html/tree/handlers.py

@@ -29,6 +29,16 b' from ..utils import url_path_join, path2url, url2path, url_escape'
 class TreeHandler(IPythonHandler):
     """Render the tree view, listing notebooks, clusters, etc."""
 
+    def generate_breadcrumbs(self, path):
+        breadcrumbs = [(url_escape(url_path_join(self.base_project_url, 'tree')), '')]
+        comps = path.split('/')
+        ncomps = len(comps)
+        for i in range(ncomps):
+            if comps[i]:
+                link = url_escape(url_path_join(self.base_project_url, 'tree', *comps[0:i+1]))
+                breadcrumbs.append((link, comps[i]))
+        return breadcrumbs
+
     @web.authenticated
     def get(self, path='', name=None):
         path = path.strip('/')
@@ -44,10 +54,12 b' class TreeHandler(IPythonHandler):'
             if not nbm.path_exists(path=path):
                 # no such directory, 404
                 raise web.HTTPError(404)
+            breadcrumbs = self.generate_breadcrumbs(path)
             self.write(self.render_template('tree.html',
                 project=self.project_dir,
                 tree_url_path=path,
                 notebook_path=path,
+                breadcrumbs=breadcrumbs
             ))