Move tree node widget code to the widgets.py file and prettify a bit

apps/document_indexing/widgets.py

@@ -1,6 +1,8 @@
+# -*- coding: utf-8 -*-
 from __future__ import absolute_import
 
-from django.utils.safestring import mark_safe
+#from django.utils.safestring import mark_safe
+from django.utils.html import conditional_escape, mark_safe
 
 from .models import IndexInstanceNode
 
@@ -71,3 +73,18 @@ def get_breadcrumbs(index_instance, simple=False, single_link=False, include_cou
     else:
         output.insert(0, u' / '.join(result))
         return mark_safe(u' '.join(output))
+     
+
+def node_level(x):
+    """
+    Render an indented tree like output for a specific node
+    """
+    return mark_safe(
+        u''.join(
+            [
+                u'     ' * (getattr(x, x._mptt_meta.level_attr) - 1),
+                u'' if x.parent else u'',
+                unicode(x if x.parent else 'root')
+            ]
+        )
+    )