Documentation: FsmDefinition.php

Original file: src/Fsm/Contracts/FsmDefinition.php

FsmDefinition Documentation

Table of Contents

• Introduction
• Methods
  • define

Introduction

The file FsmDefinition.php defines an interface for creating configurations for Finite State Machines (FSMs) within the context of a PHP application, specifically designed for use with the Laravel framework. This interface lays out the essential method that any class implementing FsmDefinition must contain, ensuring that the FSM configurations can be consistently defined across different implementations. The primary goal is to leverage the FsmBuilder class to establish states and transitions in a structured manner, promoting code reusability and maintainability.

Methods

define

public function define(): void;

Purpose

The define method is intended to configure the states and transitions of a finite state machine. It must be implemented by any class that adheres to the FsmDefinition interface.

Parameters

This method does not accept any parameters.

Return Values

This method does not return any values. It has a void return type, meaning its purpose is solely to establish the FSM configuration.

Functionality

The define method is crucial for laying out the structure of the finite state machine. When implementing this method, the developer will utilize the FsmBuilder::for() method to define:

• States: Individual states that the FSM can be in (e.g., idle, active, completed).
• Transitions: Rules that determine how and when the FSM can switch states.

Here is an example of how one might implement the define() method in a concrete class that implements the FsmDefinition interface:

use Fsm\FsmBuilder;

class MyFsmDefinition implements FsmDefinition
{
    public function define(): void
    {
        FsmBuilder::for('my_fsm')
            ->addState('idle')
            ->addState('processing')
            ->addState('completed')
            ->addTransition('idle', 'start', 'processing')
            ->addTransition('processing', 'complete', 'completed')
            ->addTransition('completed', 'reset', 'idle');
    }
}

In this example:

• The FSM is defined with three states: idle, processing, and completed.
• It includes transitions that allow moving from one state to another based on specific events (e.g., starting processing, completing the task, resetting to idle).

By adhering to the FsmDefinition contract, developers can create scalable and maintainable FSM implementations within their PHP applications, streamlining the process of state management.

This design pattern supports clean code principles by clearly separating the FSM's configuration from its logic, allowing for easier testing and modification.