Custom Code Handlers

Custom code handlers are included in all Rierino platform versions, providing ability to incorporate highly customized logic and actions

Custom code handlers support dynamic scripts, runtime-loaded Java code, hot-swapped packages, and Python procedures.

Use this page for handler-level details:

• Class names

• Handler parameters

• Runtime dependencies

• Built-in runtime behavior

Use Custom Code Actions for action-level saga step fields and parameters.

Run Scripts

Class: com.rierino.handler.ScriptLoadedEventHandler

Executes stored scripts through Javax scripting engines.

Handler parameters

Parameter	Definition	Example	Default
code.state	State manager storing code definitions	customJSCodes	handler_code
code.domain	Code category allowed for this handler	custom_calculation	-

Action details: Run Scripts

Run Java Code

Class: com.rierino.handler.OpenHFTEventHandler

Loads and executes dynamic Java handler code during runtime.

Handler parameters

Parameter	Definition	Example	Default
code.state	State manager storing code definitions	customCodes	handler_code
code.domain	Code category allowed for this handler	basket_operations	-
code.local.dir	Local directory used to store dynamic code	/tmp	java.io.tmpdir

Action details: Run Java Code

Run Java Package

Class: com.rierino.handler.JarLoadedEventHandler

Loads and executes packaged Java handlers during runtime.

Handler parameters

Parameter	Definition	Example	Default
jar.state	State manager storing jar definitions	customJars	handler_jar
jar.domain	Jar category allowed for this handler	basket_operations	-
jar.local.dir	Local directory used to store jars	/tmp	java.io.tmpdir

Action details: Run Java Package

Run Python Procedure

Class: com.rierino.handler.py4j.Py4JEventHandler

Calls Python code through Py4J for runtime event processing.

Handler parameters

This handler has no special parameters.

Runtime dependency

implementation (group:'com.rierino.custom', name: 'py4j', version:"${rierinoVersion}")

Runtime note

This handler typically requires an extra container alongside the runner, such as ghcr.io/rierino-open/py-runner.

Action details: Run Python Procedure