State Machine

---

This package provides a generic implementation of the state machine pattern.

Real world examples

Article Lifecycle

Rules / Business process of an article lifecycle:

• A draft article can be submitted to get reviewed: Draft --Submit-> InReview
  • Guard: a draft article need to have all the required meta data
• The article in review can be approved so it will be scheduled for publication: InReview --Approve-> Scheduled
  • Guard: the published_at date has to be in the future or it gets published right away when it is null or in the past
• Scheduled articles gets published: Scheduled --Publish-> Published
  • Guard: published_at is now or in the past
• Updating draft articles or articles in review will get back into draft status : Draft/InReview --Update-> Draft
  • Guard: current acting user has to be the author of the article
• Already published articles can be archived: Published --Archive-> Archived
  • no guard

// ArticleState should be an Enum/BackedEnum or string constants
enum ArticleState {
    case Draft;
    case InReview;
    case Scheduled;
    case Published;
    case Archived;
}
// ArticleEvent should be an Enum/BackedEnum or string constants
enum ArticleEvent {
    case Submit;
    case Approve;
    case Publish;
    case Update;
    case Archive;
}

$article = new Article();// this is your context

$articleRegistry = new \Rokde\StateMachine\TransitionRegistry();
$articleRegistry->addTransition(
    ArticleState::Draft, ArticleEvent::Submit, ArticleState::InReview,
    guard: fn($article) => $article->hasRequiredMeta(),
)->addTransition(
    ArticleState::InReview, ArticleEvent::Approve, ArticleState::Scheduled,
    guard: fn($article) => $article->published_at > now(),
)->addTransition(
    ArticleState::Scheduled, ArticleEvent::Publish, ArticleState::Published,
    guard: fn($article) => $article->published_at === null || $article->published_at <= now(),
)->addTransition(
    ArticleState::Draft, ArticleEvent::Update, ArticleState::Draft,
    guard: fn($article) => $article->author_id === currentUserId(),
)->addTransition(
    ArticleState::InReview, ArticleEvent::Update, ArticleState::Draft,
    guard: fn($article) => $article->author_id === currentUserId(),
)->addTransition(
    ArticleState::Published, ArticleEvent::Archive, ArticleState::Archived,
);

$sm = new \Rokde\StateMachine\StateMachine($articleRegistry);
$nextStatus = $sm->apply($article->status, ArticleEvent::Submit, $article);
$article->status = $nextStatus;
$article->save();

If you want a diagram representation of your process workflow, then just transform the registry to mermaid:

$transformer = new Rokde\StateMachine\Transformers\RegistryMermaidTransformer();
$mermaidCode = $transformer->transform($articleRegistry);

This results in a diagramm like this:

stateDiagram-v2
  Draft --> InReview : Submit
  Draft --> Draft : Update
  InReview --> Scheduled : Approve
  InReview --> Draft : Update
  Scheduled --> Published : Publish
  Published --> Archived : Archive

Loading

The test can also be seen in ./tests/Feature/MermaidTest.php.

Order Lifecycle

This is built in the ./tests/Feature/TransitionTest.php.

Developer Happiness

🧹 Keep a modern codebase with Pint:

composer lint

✅ Run refactors using Rector

composer refactor

⚗️ Run static analysis using PHPStan:

composer test:types

✅ Run unit tests using PEST

composer test:unit

🚀 Run the entire test suite:

composer test