Bugfixes in XmlFile translator & in base_classes datahandlers

lodel/editorial_model/translator/xmlfile.py

     for opt in elem:
         if (opt.tag == 'allowed_classes'):
             classes = list()
-            clss = opt.text.split(',')
-            for classe in clss:
-                if classe in model.all_classes():
-                    classes.append(model.all_classes_ref(classe))
-                else:
-                    new_cls = model.add_class(EmClass(classe))
-                    classes.append(new_cls)
+            if opt.text is not None:
+                clss = opt.text.split(',')
+                for classe in clss:
+                    if classe in model.all_classes():
+                        classes.append(model.all_classes_ref(classe))
+                    else:
+                        new_cls = model.add_class(EmClass(classe))
+                        classes.append(new_cls)
             dhdl_options['allowed_classes'] = classes
         elif (opt.tag == 'back_reference'):
             dhdl_options['back_reference'] = tuple(opt.text.split(','))

lodel/leapi/datahandlers/base_classes.py

     def __init__(self, allowed_classes = None, back_reference = None, internal=False, **kwargs):
         self.__allowed_classes = [] if allowed_classes is None else set(allowed_classes)
         logger.warning("We're going to inialize an temporary attribute, don't forget to fix this issue")
-        self.allowed_classes = None if allowed_classes is None else allowed_classes.pop() ## WARNING : just here for step over the issue with __allowed_classes
         if back_reference is not None:
             if len(back_reference) != 2:
                 raise ValueError("A tuple (classname, fieldname) expected but got '%s'" % back_reference)

plugins/webui/templates/listing/show_object.html

                     <li>{{ fieldname }}
                         <ul>
                     {% for rel in obj.data(fieldname) %}
-                            {% set l_classe = fieldvalue.allowed_classes %}
+                            {% set l_classe = fieldvalue.linked_classes() %}
                             <li><a href="show_object?classname={{ l_classe.__name__ }}&lodel_id={{ rel|int }}" target="_blank">{{ rel|int }}</a></li>
                     {% endfor %}
                         </ul></li>
         {% endif %}
     {% endfor %}
 </ul>
-{% endblock %}
+{% endblock %}