BusinessTemplate: don't export in a different file for missing attribute case.

Only xml metadata should be exported in this case.
In the previous version the check of hasattr could pass
if attribute is defined as an attribute of the class and not of the instance,
causing also AttributeError later when the code tries to invoke delattr.

Also, restructure export. First try to delete property and then
export as separate file.

Test also added.

product/ERP5/Document/BusinessTemplate.py

@@ -857,39 +857,47 @@ class ObjectTemplateItem(BaseTemplateItem):
         if property_and_extension_exported_separately_dict:
           for record_id, record in property_and_extension_exported_separately_dict.iteritems():
             extension = record
-            exported_property_type = record_id
-            if hasattr(obj, exported_property_type):
-              exported_property = getattr(obj, exported_property_type)
+            # we copy the object from the context. Sometimes this changes
+            # output_encoding, so we keep it here to restore.
+            reset_output_encoding = False
+            if hasattr(obj, 'output_encoding'):
+              reset_output_encoding = True
+              output_encoding = obj.output_encoding
+            obj = obj._getCopy(context)
+            try:
+              exported_property = getattr(obj, record_id)
+              # Delete this attribute from the object.
+              # in case the related Portal Type does not exist, the object may be broken.
+              # So we cannot delattr, but we can delete the key of its its broken state
+              if isinstance(obj, ERP5BaseBroken):
+                del obj.__Broken_state__[record_id]
+                obj._p_changed = 1
+              else:
+                delattr(obj, record_id)
+            except (AttributeError, KeyError):
+              # property was not set on instance,
+              # do nothing, only .xml metadata will be exported
+              pass
+            else:
+              # export a separate file with the data
               if isinstance(exported_property, unicode):
                 exported_property = str(exported_property.encode('utf-8'))
               elif not isinstance(exported_property, str):
                 exported_property = str(exported_property)
-
-              reset_output_encoding = False
-              if hasattr(obj, 'output_encoding'):
-                reset_output_encoding = True
-                output_encoding = obj.output_encoding
-              obj = obj._getCopy(context)
-
               f = StringIO(exported_property)
               bta.addObject(f, key, path=path, ext=extension)
 
-              # since we get the obj from context we should
-              # again remove useless properties
-              obj = self.removeProperties(obj, 1, keep_workflow_history = True)
+            # since we get the obj from context we should
+            # again remove useless properties
+            obj = self.removeProperties(obj, 1, keep_workflow_history = True)
 
-              # in case the related Portal Type does not exist, the object may be broken.
-              # So we cannot delattr, but we can delet the het of its its broken state
+            if reset_output_encoding:
               if isinstance(obj, ERP5BaseBroken):
-                del obj.__Broken_state__[exported_property_type]
-                if reset_output_encoding:
-                  self._objects[obj_key].__Broken_state__['output_encoding'] = output_encoding
+                self._objects[obj_key].__Broken_state__['output_encoding'] = output_encoding
                 obj._p_changed = 1
               else:
-                delattr(obj, exported_property_type)
-                if reset_output_encoding:
-                  obj.output_encoding = output_encoding
-              transaction.savepoint(optimistic=True)
+                obj.output_encoding = output_encoding
+            transaction.savepoint(optimistic=True)
 
         f = StringIO()
         XMLExportImport.exportXML(obj._p_jar, obj._p_oid, f)

product/ERP5/tests/testBusinessTemplateTwoFileExport.py

@@ -1023,3 +1023,48 @@ AAAFCAYAAACNbyblAAAAHElEQVQI12P4//8/w38GIAXDIBKE0DHxgljNBAAO
     self.assertTrue(os.path.exists(os.path.join(self.export_dir, 'bt')))
     self.assertTrue(os.path.exists(test_component_path+'.xml'))
     self.assertTrue(os.path.exists(test_component_path+'.py'))
+
+  def test_twoFileImportExportForFileWithNoData(self):
+    """
+      Test Business Template Import And Export With File
+      that has no data attribute. Only .xml metadata is exported
+    """
+    file_title = "foo"
+
+    file_document_kw = {"title": file_title,
+                        "portal_type": "File"}
+
+    file_page = self.portal.document_module.newContent(**file_document_kw)
+
+    # 'data' is not in the __dict__ of the File instance
+    self.assertFalse('data' in file_page.__dict__)
+    # Nonetheless, 'data' is defined in File class as empty string
+    self.assertEquals(getattr(file_page, 'data'), '')
+
+    file_document_kw['id'] = file_id = file_page.getId()
+
+    self.template.edit(template_path_list=['document_module/'+file_id,])
+
+    file_document_path = os.path.join(self.cfg.instancehome, self.export_dir,
+                                     'PathTemplateItem', 'document_module',
+                                      file_id)
+
+    self.template.build()
+    self.tic()
+    self.template.export(path=self.export_dir, local=True)
+    self.tic()
+
+    self.assertTrue(os.path.exists(file_document_path+'.xml'))
+    # check that there is no other file exported
+    self.assertEqual(len(os.listdir(file_document_path.rsplit('/', 1)[0])), 1)
+
+    import_template = self._importBusinessTemplate()
+
+    self.portal.document_module.manage_delObjects([file_id])
+
+    import_template.install()
+
+    file_page = self.portal.document_module[file_id]
+
+    for property_id, property_value in file_document_kw.iteritems():
+      self.assertEqual(getattr(file_page, property_id), property_value)