Handle possible None values for obj when the element is optional

ChangeLog

@@ -1,3 +1,8 @@
+2010-02-04 Ozan Çağlayan <ozan@pardus.org.tr>
+		* pisi/pxml/autoxml.py (format): Some optional elements may be None
+		during formatting, handle those situations. We still have a formatting
+		issue caused by the automagical output representation of autoxml.
+
 2010-02-02 Ozan Çağlayan <ozan@pardus.org.tr>
 		* pisi/component.py(Maintainer): Add Maintainer tag to components.xml.
 

pisi/pxml/autoxml.py

@@ -727,11 +727,16 @@ class autoxml(oo.autosuper, oo.autoprop):
             return obj.errors(where)
 
         def format(obj, f, errs):
-            try:
-                obj.format(f, errs)
-            except Error:
+            if obj:
+                try:
+                    obj.format(f, errs)
+                except Error:
+                    if req == mandatory:
+                        errs.append(_('Object cannot be formatted'))
+            else:
                 if req == mandatory:
                     errs.append(_('Mandatory argument not available'))
+
         return (init, decode, encode, errors, format)
 
     def gen_list_tag(cls, tag, spec):
@@ -841,9 +846,13 @@ class autoxml(oo.autosuper, oo.autoprop):
             return obj.errors(where)
 
         def format(obj, f, errs):
-            try:
-                obj.format(f, errs)
-            except Error:
+            if obj:
+                try:
+                    obj.format(f, errs)
+                except Error:
+                    if req == mandatory:
+                        errs.append(_('Object cannot be formatted'))
+            else:
                 if req == mandatory:
                     errs.append(_('Mandatory argument not available'))