Strongly Typed Events 0.3.0 – now with Signals
Turns out that I needed an even smaller type of event: the signal. It is an event that has no data; it just fires. The Strongly Typed Events project started with the IEvent that was styled after the way .Net does event handling. Then the ISimpleEvent was added in 0.2.0, for scenarios when no sender is necessary. Now I've added the ISignal to version 0.3.0.
Why would we need another event type?
While programming a new TypeScript project, I got the need for a timer mechanism. I only need an event without data - much like a simple egg-timer. Implementing those events as an ISimpleEvent looks ridiculous, that's why I created the ISignal and its counterparts.
Traffic light example
Its usage is best illustrated with a piece of example code. Let's create a somewhat static traffic light that will switch colors based on time. Remember: I'm Dutch, so the middle color will be orange!
class TrafficLight {
private _signals = new SignalList();
private _color = 'red';
public constructor(
public greenMs: number,
public orangeMs: number,
public redMs: number
) {
this.onSwitchToGreen.subscribe(() => this._color = 'green');
this.onSwitchToOrange.subscribe(() => this._color = 'orange');
this.onSwitchToRed.subscribe(() => this._color = 'red');
this.internalStart();
}
public get color(): string {
return this._color;
}
public get onSwitchToGreen(): ISignal {
return this._signals.get('green').asEvent();
}
public get onSwitchToRed(): ISignal {
return this._signals.get('red').asEvent();
}
public get onSwitchToOrange(): ISignal {
return this._signals.get('orange').asEvent();
}
private internalStart(): void {
window.setTimeout(() => {
this._signals.get('green').dispatch();
window.setTimeout(() => {
this._signals.get('orange').dispatch();
window.setTimeout(() => {
this._signals.get('red').dispatch();
this.internalStart();
}, this.orangeMs);
}, this.greenMs)
}, this.redMs)
}
}You can subscribe and unsubscribe from the signals in the usual way:
var light = new TrafficLight(5000, 1500, 10000);
light.onSwitchToGreen.subscribe(() => console.log('Light is green.'));
light.onSwitchToOrange.subscribe(() => console.log('Light is orange.'));
light.onSwitchToRed.subscribe(() => console.log('Light is red.'));The usual suspects
All of the usual suspects are present:
Other changes
I've removed the version numbers from the file names which makes updating easier. The tests are now wrapped in modules and have a string comment attached to them.