StateMachine Library

Overview

The StateMachine Library is a flexible, extendable, and fluent .NET library for managing state transitions, evaluating conditions, and triggering actions based on the state of an object. The library supports dynamic state transitions, condition evaluations, and trigger-based mechanisms for automating workflows.

Key Features

• Manage state transitions with conditions stored in a database or defined in code.
• Evaluate object conditions dynamically using expressions.
• Trigger actions based on conditions with automatic logging and notification support.
• Fluent API for easy configuration and extension.
• Support for complex workflows with multiple transition options (e.g., Approve, Reject, Cancel, Void).

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Installation

1. Clone the repository:

   git clone https://github.com/your-repo-url.git

2. Add the library project to your solution.
3. Reference the library in your main project.

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Getting Started

Define a State Transition

Use the StateMachine class to define a state transition:

var stateMachine = new StateMachine();

stateMachine.AddTransition("Pending", "Approved")
            .WithCondition(obj => obj.Amount > 100)
            .WithTrigger(obj => obj.Status = "Approved");

Evaluate Triggers

To evaluate a set of triggers:

var triggerManager = new TriggerManager();

triggerManager.AddTrigger(
    obj => obj.Status == "Pending" && obj.Amount > 100,
    obj => obj.Status = "Approved"
);

triggerManager.EvaluateTriggers(myObject);

Get Previous State

Use the GetPreviousState method to retrieve the previous state of a record:

var previousState = stateMachine.GetPreviousState(myObject);

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Fluent API Usage

The library provides a fluent API for configuring transitions and triggers:

var stateMachine = new StateMachine()
    .AddTransition("Draft", "Submitted")
        .WithCondition(obj => obj.IsComplete)
        .WithTrigger(obj => obj.Message = "Submission successful")
    .AddTransition("Submitted", "Approved")
        .WithCondition(obj => obj.ReviewScore > 80)
        .WithTrigger(obj => obj.Status = "Approved");

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Advanced Features

TODO: Notifications

You can add notifications that will be triggered when a condition is met:

triggerManager.AddTrigger(
    obj => obj.Status == "Pending",
    obj => obj.Notification = "Your request is pending approval."
);

Automatic Logging

Enable automatic logging of state transitions and actions:

stateMachine.EnableLogging(log => Console.WriteLine(log));

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Customization

You can extend the library by:

• Adding custom conditions.
• Creating custom triggers.
• Implementing additional logging mechanisms.
• Supporting different object types and properties dynamically.

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Example Workflow

Here’s an example of using the library to manage a bid evaluation workflow:

var stateMachine = new StateMachine();

stateMachine.AddTransition("EOI Sent", "Bid Received")
    .WithCondition(obj => obj.BidEvaluationTypeId == BidEvaluationTypeCodes.DIRECT_CONTRACTING)
    .WithTrigger(obj => ViewBag.allowEOI = true);

stateMachine.AddTransition("Bid Received", "Bids Evaluated")
    .WithCondition(obj => obj.EOISent && obj.Bids.Count > 0)
    .WithTrigger(obj => ViewBag.Eoi = true);

stateMachine.EvaluateTriggers(bidObject);

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Best Practices

• Use meaningful state names and conditions to ensure clarity in your workflows.
• Utilize logging to track state changes and triggers for debugging purposes.
• Keep triggers modular and reusable.

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Contributing

Contributions are welcome! Please follow these steps:

1. Fork the repository.
2. Create a new branch for your feature or bugfix.
3. Submit a pull request for review.

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License

This project is licensed under the MIT License.

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Contact

For any questions or feedback, please contact [your-email@example.com].