Add xml string gen

histories/models.py

@@ -136,6 +136,10 @@ class History(models.Model):
         if standalone:
             return xml_root
 
+    def to_xml_string(self):
+        xml = self.to_xml()
+        return ET.tostring(xml)
+
     @staticmethod
     def from_xml(xml_root):
         ''' Loads an history from an XML file '''