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Plugin Development

Turing-workflow can be extended through a plugin architecture. This document explains plugin types, design principles, loading mechanisms, and available system resources.

Plugin Types​

Turing-workflow has two types of plugins.

General Plugin​

A plugin that provides arbitrary functionality. It is called during workflow execution and can implement any processing such as data transformation, external service integration, or custom logic.

SectionBuilder (Report Section Builder)​

A specialized plugin for generating report sections. It builds each section of the report from workflow execution results. It implements the SectionBuilder interface and defines the section's title, content, and display order.

POJO + IIAR Architecture Principles​

Plugins follow the POJO-actor framework's IIAR (Input-Input-Action-Response) pattern.

  • POJO (Plain Old Java Object): Plugins minimize dependencies on special framework classes, ensuring testability
  • IIAR: A message-passing pattern based on the actor model where each plugin operates as an independent actor
  • Immutability: Messages are designed as immutable objects to ensure thread safety
  • Single Responsibility: Each plugin focuses on one clear function

Plugin Loading​

Plugins are dynamically loaded through the loader actor.

loadJar - Loading JAR Files​

The loader actor's loadJar method adds plugin classes from external JAR files to the classpath.

loader.loadJar("path/to/my-plugin.jar")

createChild - Creating Plugin Actors​

The createChild method creates plugin actors from loaded classes. The generated actors are managed as child actors of the actor system.

loader.createChild("com.example.MyPlugin")

This two-step process allows the actor system to centrally manage plugin lifecycles.

Available System Resources​

The following system resources are available to plugins.

DB Connection (DistributedLogStore)​

Database connections to H2 can be obtained through the DistributedLogStore interface. It is used for reading and writing workflow execution logs and persisting custom data. For details, see database-connection.

Session ID​

A unique ID that identifies the current workflow execution session. It is used for log association and session-specific data management.

Actor System (IIActorSystem)​

A reference to the POJO-actor framework's actor system. It provides access to actor model features such as sending messages to other actors and creating new actors.

Reference Implementation​

A basic report section builder implementation is provided as a reference for plugin development.

com.scivicslab.turingworkflow.plugins.report.sections.basic

This package contains standard section builders such as:

  • Summary Section: Generates a workflow execution overview
  • Node Status Section: Lists execution results for each node
  • Timeline Section: Visualizes execution time

Use these implementations as references for developing your own SectionBuilders. General Plugins can be implemented following similar patterns.