diff -r 80ce81208b08 -r 3051b847c124 server/python/django2/renkanmanager/utils.py
--- a/server/python/django2/renkanmanager/utils.py	Tue Jun 21 10:30:08 2016 +0200
+++ b/server/python/django2/renkanmanager/utils.py	Tue Jun 21 17:53:06 2016 +0200
@@ -10,6 +10,7 @@
 from django.shortcuts import get_object_or_404
 from django.utils.encoding import smart_str
 from renkanmanager.models import Renkan
+import distutils
 import math
 import hashlib
 import re
@@ -29,12 +30,12 @@
 
 
 class NodePlacer():
-    
+
     cat_nb_nodes = {}
-    
+
     def init(self, cat_nb_nodes_initial):
         raise NotImplementedError( "Should have implemented init" )
-    
+
     def get_place(self, category):
         if not category or category not in self.cat_nb_nodes:
             raise Http404
@@ -43,9 +44,9 @@
 
 
 class LineNodePlacer(NodePlacer): #vertical lines
-    
+
     max_length = 0
-    
+
     def init(self, cat_nb_nodes_initial):
         for c in cat_nb_nodes_initial:
             nb = cat_nb_nodes_initial[c]
@@ -67,9 +68,9 @@
 
 
 class HorLineNodePlacer(NodePlacer): #horizontal lines
-    
+
     max_length = 0
-    
+
     def init(self, cat_nb_nodes_initial):
         for c in cat_nb_nodes_initial:
             nb = cat_nb_nodes_initial[c]
@@ -93,7 +94,7 @@
                         self.cat_nb_nodes[c].append({ "x": 100*(i+offset), "y": order*450 })
 
 class CircleNodePlacer(NodePlacer):
-    
+
     def init(self, cat_nb_nodes_initial):
         for i_cat,c in enumerate(cat_nb_nodes_initial):
             self.cat_nb_nodes[c] = []
@@ -133,4 +134,8 @@
         raise ValidationError("You are not allowed to remove this renkan")
 
 
-
+def parse_bool(value):
+    try:
+        return bool(value and distutils.util.strtobool(value.lower()))
+    except ValueError:
+        return False