levit_reactive 0.0.5

Pure Dart reactive state management primitives. The engine of the Levit framework.

levit_reactive

A pure Dart reactive engine. Deterministic. Fine-grained. Dependency-free.

levit_reactive is the foundational reactivity layer of the Levit ecosystem. It provides a high-performance, zero-boilerplate way to model state, derived values, and asynchronous data flows in any Dart environment.

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Purpose & Scope

levit_reactive manages reactive state and its derivation graph. It is responsible for:

• Zero-Boilerplate Reactivity: Create reactive state via simple .lx extensions.
• Automatic Dependency Tracking: Computed values track their sources automatically.
• Async Status Modeling: Type-safe LxStatus hierarchy for async operation states.
• Reactive Collections: LxList, LxMap, and LxSet for collection-level reactivity.
• Middleware Interception: Global hooks for logging, undo/redo, and diagnostics.

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Core Abstractions

Type	Description
LxReactive<T>	Base interface for all reactive objects
LxVar<T>	Mutable reactive variable
LxComputed<T>	Derived state with automatic dependency tracking
LxAsyncComputed<T>	Async derived state returning LxStatus<T>
LxStatus<T>	Sealed hierarchy: LxIdle, LxWaiting, LxSuccess, LxError
LxList<E>, LxMap<K,V>, LxSet<E>	Reactive collections
LxWorker<T>	Side-effect observer with monitoring
Lx	Static entry point for batching and configuration

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Getting Started

Basic Reactivity

final count = 0.lx;
count.addListener(() => print('Count: ${count.value}'));
count.value++;

Computed Values

final firstName = 'John'.lx;
final lastName = 'Doe'.lx;
final fullName = LxComputed(() => '${firstName.value} ${lastName.value}');
print(fullName.value); // John Doe

Async State

final user = LxAsyncComputed(() => fetchUser(123));

if (user.isWaiting) {
  print('Loading...');
}

Batching

Lx.batch(() {
  count.value = 1;
  name.value = 'Updated';
}); // Single notification

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Design Principles

Transparent Reactivity

Reactivity is achieved by simply reading values. No manual subscription management, annotations, or code generation required.

Determinism

Notifications are synchronous and topologically sorted. A single state change never results in inconsistent derived values or redundant updates.

Pure Dart

Zero dependencies and no platform-specific requirements, making it suitable for backend services, CLI tools, and complex UIs.