1 files changed, 11 insertions, 8 deletions
diff --git a/Param/String/__init__.py b/Param/String/__init__.py
index fe6b6c1..df65c9d 100644
--- a/Param/String/__init__.py
+++ b/Param/String/__init__.py
@@ -1,13 +1,16 @@
 from Param import Param
+import re
 
-def ParamString(Param):
+class ParamString(Param):
   def __init__(self, value, classname=""):
-    self._classname = classname
-    super(ParamString).__init__()
-    try:
-      self.value = self.sanitize(value)
-    except Exception as e:
-      self.err_warn("Unable to sanitize: %s" % str(value))
-      self.err_warn(str(e))
+    super(ParamString, self).__init__(classname=classname)
+    if value:
+      try:
+        self.value = self.sanitize(value)
+      except Exception as e:
+        self.err_warn("Unable to sanitize: %s" % str(value))
+        self.err_warn(str(e))
+    else:
+      self.value = ""
   def sanitize (self, s):
     return re.sub(r'\W+', '', s)