SpiffWorkflow 1.0.0

A workflow framework and BPMN/DMN Processor

SpiffWorkflow

Spiff Workflow is a workflow engine implemented in pure Python. It is based on the excellent work of the Workflow Patterns initiative. In 2020 and 2021, extensive support was added for BPMN / DMN processing.

Motivation

We created SpiffWorkflow to support the development of low-code business applications in Python. Using BPMN will allow non-developers to describe complex workflow processes in a visual diagram, coupled with a powerful python script engine that works seamlessly within the diagrams. SpiffWorkflow can parse these diagrams and execute them. The ability for businesses to create clear, coherent diagrams that drive an application has far reaching potential. While multiple tools exist for doing this in Java, we believe that wide adoption of the Python Language, and it's ease of use, create a winning strategy for building Low-Code applications.

Build status

Code style

Screenshots

Dependencies

We've worked to minimize external dependencies. We rely on lxml for parsing XML Documents, and there is some legacy support for Celery, but it is not core to the implementation, it is just a way to interconnect these systems. Built with

• lxml
• celery

Features

• BPMN - support for parsing BPMN diagrams, including the more complex components, like pools and lanes, multi-instance tasks, sub-workflows, timer events, signals, messages, boudary events and looping.
• DMN - We have a baseline implementation of DMN that is well integrated with our Python Execution Engine.
• Forms - forms, including text fields, selection lists, and most every other thing you can be extracted from the Camunda xml extension, and returned as json data that can be used to generate forms on the command line, or in web applications (we've used Formly to good success)
• Python Workflows - We've retained support for building workflows directly in code, or running workflows based on a internal json data structure.

A complete list of the latest features is available with our release notes for version 1.0.

Code Examples and Documentation

Detailed documentation is available on ReadTheDocs Also, checkout our example application, which we reference extensively from the Documentation.

Installation

pip install spiffworkflow

Tests

cd tests
./run_suite.sh

Contribute

Pull Requests are and always will be welcome!

Please check your formatting, assure that all tests are passing, and include any additional tests that can demonstrate the new code you created is working as expected. If applicable, please reference the issue number in your pull request.

Credits and Thanks

Special Thanks: Sartography (Sartography.com) undertook these efforts to support the development of a custom web application for the University of Virginia. We would like to thank UVA for their support and trust in allowing us to take on the mammoth task of building a general-purpose workflows system, and contributing something back to the open source community.

Bruce Silver, the author of BPMN Quick and Easy Using Method and Style, whose work we referenced extensively as we made implementation decisions and educated ourselves on the BPMN and DMN standards.

Samuel Abels (@knipknap) for keeping SpiffWorkflow alive for the past few years, and offering us commit access to make these contributions, and Matthew Hampton for kicking this project off and giving us sound footing on which to build.

The BPMN.js library, without which we would not have the tools to effectively build out our models, embed an editor in our application, and pull this mad mess together.

Kelly McDonald (@w4kpm) who dove deeper into the core of SpiffWorkflow than anyone else, and was instrumental in helping us get some of these major enhancements working correctly.

We would like to thank Denny Weinberg for his early contributions to DMN support, which we used as a baseline and then extended.

License

GNU LESSER GENERAL PUBLIC LICENSE