X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=sfa%2Futil%2Fnamespace.py;h=cc140d5a409db88c20fa699baf960320d3265e20;hb=5a7686e2e17d6dd86c13895ea2876a31f09bc4a2;hp=61b05b9142747eda430a19dc30cc75589abf6f59;hpb=3d7237fa0b5f2b4a60cb97c7fb3b6aecfd94558a;p=sfa.git

diff --git a/sfa/util/namespace.py b/sfa/util/namespace.py
index 61b05b91..cc140d5a 100644
--- a/sfa/util/namespace.py
+++ b/sfa/util/namespace.py
@@ -57,8 +57,9 @@ def urn_to_hrn(urn):
     """
 
     # if this is already a hrn dont do anything
-    if not urn.startswith(URN_PREFIX):
+    if not urn or not urn.startswith(URN_PREFIX):
         return urn, None
+
     name = urn[len(URN_PREFIX):]
     hrn_parts = name.split("+")
     
@@ -71,7 +72,7 @@ def urn_to_hrn(urn):
     # join list elements using '.'
     hrn = '.'.join([part.replace(':', '.') for part in hrn_parts if part]) 
    
-    return hrn, type 
+    return str(hrn), str(type) 
     
     
 def hrn_to_urn(hrn, type=None):
@@ -79,7 +80,7 @@ def hrn_to_urn(hrn, type=None):
     convert an hrn and type to a urn string
     """
     # if  this is already a urn dont do anything 
-    if hrn.startswith(URN_PREFIX):
+    if not hrn or hrn.startswith(URN_PREFIX):
         return hrn
 
     authority = get_authority(hrn)