Configure Bliss Objects for Online Data Processing#

A Bliss object is an instance of a python class that is instantiated when starting the Bliss terminal for a specific Bliss session.

All classes in blissoda that manage data processing with Ewoks derive from blissoda.automation.BlissAutomationObject which allows these classes to be used for Bliss objects.

Bliss objects are configured in Beacon. The Beacon configuration is expected to use the generic plugin. For example:

- name: my_processor
  plugin: generic
  class: MyProcessor
  package: blissoda.mycategory.my_processor
  default_parameters:
    param1: value1
    param2: value2
  shared: false
  singleton: true

  • default_parameters: Initial values for parameters stored in Redis.

  • shared: If True, parameters are shared between Bliss sessions. Default: false.

  • singleton: If True, parameters are a singleton for the Bliss session (shared=False)

    or globally (shared=True). Default: true.

Hint

Singleton means that all Bliss objects instantiated from the same class, regardless of their names, refer to the same underlying Redis hash. They therefore share the same persistent parameter set.

Then add it to the objects of any Bliss session configuration in Beacon:

- class: Session
  name: eh1
  setup-file: ./eh1_setup.py
  config-objects:
    - my_processor

Depending on the implementation of MyProcessor, the parameters in default_parameters are typically only used when they do not exist in Redis yet for the Bliss session in which the object is used. So after the first time the value from Redis is used and can be changed from the Bliss terminal as follows

DEMO_SESSION [3]: my_processor
        Out [3]:
                Parameters:
                param1   'value1'
                param2   'value2'
DEMO_SESSION [4]: my_processor.param1 = "CHANGED"
DEMO_SESSION [5]: my_processor
        Out [5]:
                Parameters:
                param1   'CHANGED'
                param2   'value2'

To copy and remove the values of another instance, most often after changing the Beacon configuration parameters shared, singleton or name

DEMO_SESSION [3]: my_processor.copy_and_remove_parameters(shared=True, name="old_my_processor")