Package: swf

Simple linear, human-driven workflow engine for Go.

Repository: https://github.com/dracory/swf

Overview

The workflow package allows you to create and manage linear, sequential workflows driven by human interaction. It provides functionality to:

• Create and manage steps in a sequential workflow
• Track the current step and who is responsible for it
• Determine if steps are complete
• Calculate workflow progress
• Store and retrieve metadata for steps
• Serialize and deserialize workflow state
• Visualize the workflow as a DOT graph

Note: This is a simple linear workflow system. It does not support branching/DAGs or parallel execution.

When to Use

Ideal for:

• Document approval workflows
• Employee onboarding
• Manual reviews
• Form completion wizards
• Business process checklists
• Project stage gates

Not suitable for:

• Automated or DAG/branching workflows
• Parallel processing
• Conditional branching
• Automated task execution

Components

Step

A Step represents a single step in a workflow. Each step has:

• Name: unique identifier
• Type: type (default "normal")
• Title: display title
• Description: what the step does
• Responsible: person/role responsible

Workflow

A Workflow manages multiple steps and tracks state. It can:

• Add steps in sequence
• Get and set the current step
• Check if a step is current or complete
• Calculate progress
• Store/retrieve per-step metadata
• Serialize/deserialize state
• Visualize as DOT graph

Usage

package main

import (
    "fmt"
    workflow "github.com/dracory/swf"
)

func main() {
    // Create a new linear workflow
    wf := workflow.NewWorkflow()

    // Create steps in sequence
    step1 := workflow.NewStep("step1")
    step1.Title = "Document Review"
    step1.Description = "Review the submitted document"
    step1.Responsible = "John Doe"

    step2 := workflow.NewStep("step2")
    step2.Title = "Manager Approval"
    step2.Description = "Manager approval of the document"
    step2.Responsible = "Jane Smith"

    // Add steps to the workflow in sequence
    wf.AddStep(step1)
    wf.AddStep(step2)

    // Get the current step
    current := wf.GetCurrentStep()
    fmt.Printf("Current step: %s\n", current.Name)

    // Move to the next step
    wf.SetCurrentStep(step2)

    // Check if a step is complete
    isComplete := wf.IsStepComplete(step1)
    fmt.Printf("Is step1 complete? %v\n", isComplete)

    // Progress
    p := wf.GetProgress()
    fmt.Printf("Progress: %d/%d steps completed (%.2f%%)\n", p.Completed, p.Total, p.Percents)

    // Visualize (DOT)
    dot := wf.Visualize()
    fmt.Println(dot)
}

Visualization

The DOT graph:

• Boxes for steps with titles
• Colors:
  • White: pending
  • Blue (#2196F3): current
  • Green (#4CAF50): completed
• Edges:
  • Gray (#9E9E9E): default
  • Green (#4CAF50): completed path
• Tooltips include step descriptions
• Left-to-right layout

Render with Graphviz:

• dot -Tpng workflow.dot -o workflow.png
• Or use an online Graphviz tool.