data model: transformation is called by alarm, not by interaction workflow

Interaction workflow could still be used to call the alarm right after appending to data stream

bt5/erp5_wendelin/WorkflowTemplateItem/portal_workflow/data_stream_interaction_workflow/scripts/DataStream_appendData.py

 """
-  Handle appended data chunks.
+  This script could be used to call Alarm to handle transformation right after
+  appending to data stream.
 """
-data_stream = state_change['object']
-argument_list = state_change['kwargs']['workflow_method_args']
-
-# call you own script to handle newly appended data which 
-# is not processed yet, pass data stream start end offset only
-end_offset = data_stream.getSize()
-packet_size = len(argument_list[0])
-start_offset = end_offset - packet_size
-data_stream.activate().DataStream_transformTail(start_offset, end_offset)
+pass