@alwatr/observable

Flux: Observable

A lightweight and flexible TypeScript library for implementing the observer pattern (similar to signals) with events, subscriptions, and convenient features.

Features

• Simple and Intuitive: Easy-to-use API for subscribing to and emitting events.
• TypeScript Support: Written in TypeScript with full type definitions for improved code quality and developer experience.
• Flexible Options: Control subscription behavior with options like once, priority, and receivePrevious.
• Asynchronous Support: Handle asynchronous events with Promise-based callbacks.
• Built-in Logging: Integrated logging for debugging and monitoring.

Installation

npm install @alwatr/observable

API

AlwatrObservable

• constructor(config: {name: string; loggerPrefix?: string}): Creates a new AlwatrObservable instance.

  • config.name: The name of the signal (used for logging).
  • config.loggerPrefix: Optional prefix for log messages.

• subscribe(listenerCallback: ListenerCallback<this, T>, options: SubscribeOptions = {}): SubscribeResult: Subscribes to the signal.

  • listenerCallback: The function to be called when an event is emitted.
  • options:
    • once: If true, the listener will be automatically unsubscribed after the first event.
    • priority: If true, the listener will be executed before other listeners.
    • receivePrevious: If true, the listener will be immediately called with the last emitted event (if available).
    • disabled: If true, the listener will not be executed.

• unsubscribe(listenerCallback: ListenerCallback<this, T>): Unsubscribes a listener from the signal.

• notify_(message: T): Emits an event to all subscribers.

  • message: The data to be sent to the subscribers.

• clearMessage_(): Clears the current message without notifying subscribers.

• untilNewNotify_(): Returns a Promise that resolves with the next emitted event.

Sponsors

The following companies, organizations, and individuals support flux ongoing maintenance and development. Become a Sponsor to get your logo on our README and website.

Contributing

Contributions are welcome! Please read our contribution guidelines before submitting a pull request.

License

This project is licensed under the AGPL-3.0 License.

Changelog

4.0.0 (2024-11-06)

⚠ BREAKING CHANGES

• fsm: all name of type ActionName in class actionRecord_ changed
• fsm: event 'reset' fired on calling resetToInitialState and the first time in class constructor
• fsm: initialState remove from AlwatrFetchStateMachineConfig

Bug Fixes

• fsm: remove initialState from AlwatrFetchStateMachineConfig (fcb9541) by @AliMD
• fsm: run postTransition__ in resetToInitialState_ and constructor (00ca9c1) by @AliMD
• observable: add AlwatrLogger type to logger_ property (f21b562) by @AliMD

Code Refactoring

• fsm: update action naming conventions and enhance event handling in state transitions (c3a4094) by @AliMD

Dependencies update

• update (a0c4014) by @AliMD