Node Types Overview

The Vyuh Workflow Engine provides a rich vocabulary of node types for modeling any business process.

Node Type Summary

Type	Builder Method	Description
Start	.start()	Entry point for workflow
End	.end()	Terminal point
Task	.task()	Automated work execution
User Task	.userTask()	Human task (inbox item)
Signal Wait	.signalWait()	Wait for external signal
Exclusive Gateway	.oneOf()	Route to ONE path (XOR)
Race Gateway	.anyOf()	Race paths, first wins (OR)
Parallel Gateway	.allOf()	Route to ALL paths (AND)

Basic Flow Example

final workflow = WorkflowBuilder('BASIC', 'Basic Flow')
    .start('begin')
    .task('processData', ...)
    .userTask('review', ...)
    .oneOf('decide', [...])
    .end('success')
    .end('failure')
    .connect('begin', 'processData')
    .connect('processData', 'review')
    .connect('review', 'decide')
    .build();

Node Categories

Control Flow Nodes

• Start - Single entry point
• End - Terminal points (can have multiple)

Activity Nodes

• Task - Automated tasks
• User Task - Human interaction tasks

Wait Nodes

• Signal Wait - Wait for external signals

Gateway Nodes

• Exclusive (oneOf) - Route to exactly ONE path
• Race (anyOf) - Race paths, first to complete wins
• Parallel (allOf) - Fork/join for concurrent execution

Node Structure

All nodes share common properties via WorkflowNode:

class WorkflowNode {
  final String id;                      // Unique identifier
  final String name;                    // Human-readable name
  final NodeType type;                  // Node type enum
  final NodeConfiguration? config;      // Type-safe configuration
}

Node configurations are type-safe with specific classes for each node type:

switch (node.config) {
  case TaskNodeConfiguration config:
    print('Task executor: ${config.schemaType}');
  case UserTaskNodeConfiguration config:
    print('User task title: ${config.title}');
  case GatewayNodeConfiguration config:
    print('Gateway branches: ${config.branches.length}');
  // ... other configuration types
}

Next Steps

• Start & End - Entry and terminal points
• Task Nodes - Automated work
• User Tasks - Human tasks
• Signal Wait - External triggers
• Gateways - Routing and parallelism