seng-event

Provides Classes and utilities for dispatching and listening to events.

Provides an EventDispatcher base class that adds the ability to dispatch events and attach handlers that should be called when such events are triggered. New event classes can be created by extending the AbstractEvent class provided in this module. This module also provides basic event classes BasicEvent and CommonEvent that are ready to be used with EventDispatcher.

seng-event also supports event capturing and bubbling phases, heavily inspired by existing event dispatching systems like the functionality described in the DOM Event W3 spec

Installation

yarn add seng-event

npm i -S seng-event

Basic usage

import EventDispatcher, {AbstractEvent} from 'seng-event';
import {generateEventTypes, EVENT_TYPE_PLACEHOLDER} from 'seng-event/lib/util/eventTypeUtils';

// extend EventDispatcher
class Foo extends EventDispatcher {
  ...
}

// Create your own event class
class FooEvent extends AbstractEvent {
   ...
   public static COMPLETE:string = EVENT_TYPE_PLACEHOLDER;
   ...
}
generateEventTypes({FooEvent});

// listener for events
const foo = new Foo();
const exampleHandler = (event:FooEvent) => 
{
  console.log('Handler called!', event.type, event.target);
}
foo.addEventListener(FooEvent.COMPLETE, exampleHandler);

// dispatch an event (will execute exampleHandler and log 'Handler called!')
foo.dispatchEvent(new FooEvent(FooEvent.COMPLETE));  

Documentation

View the generated documentation.

Building

In order to build seng-event, ensure that you have Git and Node.js installed.

Clone a copy of the repo:

git clone https://github.com/mediamonks/seng-event.git

Change to the seng-event directory:

cd seng-event

Install dev dependencies:

yarn

Use one of the following main scripts:

yarn build            # build this project
yarn dev              # run compilers in watch mode, both for babel and typescript
yarn test             # run the unit tests incl coverage
yarn test:dev         # run the unit tests in watch mode
yarn lint             # run eslint and tslint on this project
yarn doc              # generate typedoc documentation

When installing this module, it adds a pre-commit hook, that runs lint and prettier commands before committing, so you can be sure that everything checks out.

Contribute

View CONTRIBUTING.md

Changelog

View CHANGELOG.md

Authors

View AUTHORS.md

LICENSE

MIT © MediaMonks