Add a function to clean the xml string

This is added because the other parts of the xml are generated
without formating.

Author: ecarreras

libcomxml/core/__init__.py

@@ -17,6 +17,7 @@
         import xml.etree.cElementTree as etree
     except ImportError:
         import xml.etree.ElementTree as etree
+import re
 
 
 def get_xml_default_encoding():
@@ -25,6 +26,10 @@ def get_xml_default_encoding():
     return xml_enc
 
 
+def clean_xml(xml_string):
+    return re.sub('\s+<', '<', xml_string)
+
+
 class Field(object):
     """Base Field class
     """
@@ -249,7 +254,7 @@ def build_tree(self):
                                 continue
                             self.doc_root.append(item.doc_root)
                         elif isinstance(item, str):
-                            ele = etree.fromstring(item)
+                            ele = etree.fromstring(clean_xml(item))
                             self.doc_root.append(ele)
                         item = None
                 elif (field.parent or self.root.name) == self.root.name: