Strongly Typed Events
Add the power of events to your projects. We even have 3 flavors for you.
Event types
This project gives you the following event types:
- Events - styled after the way .Net implements events. With each event you'll get a
sender and an argument object. If you use typescript, you can implement them using generics.
- Simple events - basically the same thing, with only 1 argument.
- Signals - for when no data is needed, just the firing of the event is enough.
Subscription made easy
An example says more than a 1000 words. Imagine if you have events like this on your class:
let clock = new Clock("Smu", 1000);
//log the ticks to the console - this is a signal event
clock.onTick.subscribe(() => console.log("Tick!"));
//log the sequence parameter to the console - this is a simple event
clock.onSequenceTick.subscribe(s => console.log(`Sequence: ${s}`));
//log the name of the clock and the tick argument to the console - this is an event
clock.onClockTick.subscribe((c, n) =>
console.log(`${c.name} ticked ${n} times.`)
);
Events made easy
So let's look at the implementation from a TypeScript perspective. (Do you program NodeJs without typescript? Check this)
import { SignalDispatcher, SimpleEventDispatcher, EventDispatcher } from "strongly-typed-events";
class Clock {
private _onTick = new SignalDispatcher();
private _onSequenceTick = new SimpleEventDispatcher<number>();
private _onClockTick = new EventDispatcher<Clock, number>();
private _ticks: number = 0;
constructor(public name: string, timeout: number) {
setInterval(() => {
this._ticks += 1;
this._onTick.dispatch();
this._onSequenceTick.dispatch(this._ticks);
this._onClockTick.dispatch(this, this._ticks);
}, timeout);
}
public get onTick() {
return this._onTick.asEvent();
}
public get onSequenceTick() {
return this._onSequenceTick.asEvent();
}
public get onClockTick() {
return this._onClockTick.asEvent();
}
}
Stopping events
You can stop events from being propagated.
let dispatcher = new SignalDispatcher();
let a = 0;
dispatcher.sub(ev => {
a++;
if (a > 2) {
ev.stopPropagation();
}
});
let b = 0;
dispatcher.sub(() => { b++; });
dispatcher.dispatch();
dispatcher.dispatch();
dispatcher.dispatch();
dispatcher.dispatch();
// a should be 4, because 4 dispatches are done.");
// b should be 2, because events after the 2nd dispatch are stopped."
Packages
The project is separated into multiple packages, so you only need
to include what you need. We have the following packages:
Documentation
This project will help you to add events, event handling en event dispatching to your classes. To get you started, check:
Check the documentation or the examples for more information.
History
The change history can be found here.
Maintenance
This project is maintained by Kees C. Bakker.
