draxtor / workflow-core

Lightweight workflow engine for .NET Standard

Workflow Core

Workflow Core is a light weight workflow engine targeting .NET Standard. Think: long running processes with multiple tasks that need to track state. It supports pluggable persistence and concurrency providers to allow for multi-node clusters.

Documentation

See Tutorial here.

Fluent API

Define your workflows with the fluent API.

public class MyWorkflow : IWorkflow
{
    public void Build(IWorkflowBuilder<MyData> builder)
    {    
        builder
           .StartWith<Task1>()
           .Then<Task2>()
           .Then<Task3>;
    }
}

JSON Workflow Definitions

Define your workflows in JSON

{
  "Id": "HelloWorld",
  "Version": 1,
  "Steps": [
    {
      "Id": "Hello",
      "StepType": "MyApp.HelloWorld, MyApp",
      "NextStepId": "Bye"
    },        
    {
      "Id": "Bye",
      "StepType": "MyApp.GoodbyeWorld, MyApp"
    }
  ]
}

Sample use cases

• New user workflow

public class MyData
{
	public string Email { get; set; }
	public string Password { get; set; }
	public string UserId { get; set; }
}

public class MyWorkflow : IWorkflow
{
    public void Build(IWorkflowBuilder<MyData> builder)
    {    
        builder
            .StartWith<CreateUser>()
                .Input(step => step.Email, data => data.Email)
                .Input(step => step.Password, data => data.Password)
                .Output(data => data.UserId, step => step.UserId);
           .Then<SendConfirmationEmail>()
               .WaitFor("confirmation", data => data.UserId)
           .Then<UpdateUser>()
               .Input(step => step.UserId, data => data.UserId);
    }
}

• Saga Transactions

public class MyWorkflow : IWorkflow
{
    public void Build(IWorkflowBuilder<MyData> builder)
    {    
        builder
            .StartWith<CreateCustomer>()
            .Then<PushToSalesforce>()
                .OnError(WorkflowErrorHandling.Retry, TimeSpan.FromMinutes(10))
            .Then<PushToERP>()
                .OnError(WorkflowErrorHandling.Retry, TimeSpan.FromMinutes(10));
    }
}

builder
    .StartWith<LogStart>()
    .Saga(saga => saga
        .StartWith<Task1>()
            .CompensateWith<UndoTask1>()
        .Then<Task2>()
            .CompensateWith<UndoTask2>()
        .Then<Task3>()
            .CompensateWith<UndoTask3>()
    )
    .OnError(Models.WorkflowErrorHandling.Retry, TimeSpan.FromMinutes(10))
    .Then<LogEnd>();

Persistence

Since workflows are typically long running processes, they will need to be persisted to storage between steps. There are several persistence providers available as separate Nuget packages.

• MemoryPersistenceProvider (Default provider, for demo and testing purposes)
• MongoDB
• SQL Server
• PostgreSQL
• Sqlite
• Redis (coming soon...)

Extensions

• User (human) workflows
• HTTP wrapper for Workflow Host Service

Samples

• Hello World

• Multiple outcomes

• Passing Data

• Parallel ForEach

• While Loop

• If Statement

• Events

• Parallel Tasks

• Saga Transactions (with compensation)

• Scheduled Background Tasks

• Recurring Background Tasks

• Dependency Injection

• Deferred execution & re-entrant steps

• Looping

• Exposing a REST API

• Human(User) Workflow

• Testing

Contributors

• Daniel Gerlag - Initial work
• Jackie Ja
• Aaron Scribnor
• Roberto Paterlini

Ports

• JWorkflow (Java)
• workflow-es (Node.js)
• workflow_rb (Ruby)

License

This project is licensed under the MIT License - see the LICENSE.md file for details