strong-event v1.0.2
strong-event
a powerful event
quick start
const event = new Event()
event.on(data => console.log(data, 'index'), 1)
const subscriber = event.on(data => {
console.log(data)
subscriber.off()
})
event.pipe(filter(data => data > 1))
.on(data => console.log(data, 'filter'))
event.pipe(timer(10))
.on(data => {
Promise.resolve('same timer is sync').then(console.log)
console.log(data, 'timer1')
})
event.pipe(timer(10))
.on(data => {
console.log(data, 'timer2')
})
event.emit(1)
event.emit(2)
// 1
// 1 index
// 2 filter
// 2 index
/* delay 10 ms */
// 1 timer1
// 2 timer2
// same timer is sync
/* delay 20 ms */
// 1 timer1
// 2 timer2
// same timer is sync
api
Event instance
can add subscribers for a event & dispatch data by event
Event & ShareDataEvent extends BaseEvent.
when you call pipe will return a ShareDataEvent instance.
BaseEvent's prototype has pipe
on
emit
error
& complete
methods.
BaseEvent.prototype.on
return a subscriber instance & you can call off to unsubscribe this event
first argument is callback or option, second argument is index of this callback (sort for subscriber's callbacks, every index saved in a array)
BaseEvent.prototype.emit
dispatch event for subscribers, you can emit a value
BaseEvent.prototype.error & complete
call it & all subscribers will not accept new event
BaseEvent.prototype.pipe
return a ShareDataEvent instance, & share subscribers info with event instance
argument is scheduler. like timer, filter, scan and so on. it can control subscribe(callback) how to work
you can call event or shareDataEvent emit & all of event's subscribers and all of shareDataEvent's subscribers will accept
Event
methods | arguments | description | other |
---|---|---|---|
useServer | Server | Server for scheduler | see scheduler |
extendEventServer | Event instance | assign Servers from event | see scheduler |
scheduler
builtIn schedulers
map
filter
debounceTime
timer
async
scan
you can write a scheduler, it is a simple higher-order function. but some time scheduler need a control too
// filter
function filter(fn) {
return (data, next) => {
fn(data) && next(data)
}
}
// timer
function timer(time) {
return (data, next, {timerServer}) {
timerServer(() => next(data), time)
}
}
so you can see same timer subscriber can call sync, becaseof Server
how to write a Server
you need use Server ?
how it work?
class BaseEvent {
emit(data) {
const servers = serverFactory.create() // return all Servers of event & new them
subscribers.forEach(subscriber => exector(data, servers))
}
}
// ServerFactory
class ServerFactory {
create() {
return new ServerInstance(this.servers);
}
}
class ServerInstance {
constructor(servers) {
Object.keys(servers).forEach((key) => {
this[key] = (new servers[key]()).init();
});
}
}
so every time you emit, will provid servers instance.
ServerClass must extends Server, if not useServer will not work.
export class TimerServer extends Server {
constructor() {
super();
this.data = {};
this.id = 1;
this.isUpdate = false;
}
add(cb, time) {
if (this.isUpdate === false) {
this.isUpdate = true;
Promise.resolve().then(() => {
this.isUpdate = false;
delete this.data[this.id];
this.id++;
});
}
if (!this.data[this.id] || !this.data[this.id][time]) {
if (!this.data[this.id]) this.data[this.id] = {};
this.data[this.id][time] = [cb];
const list = this.data[this.id][time];
setTimeout(() => list.forEach(fn => fn()), time);
} else {
this.data[this.id][time].push(cb);
}
return this.data[this.id];
}
init() {
return (cb, time) => this.add(cb, time);
}
}
name is class name but initial replaceto lowercase
about global Server
some time most of event instances need same Servers
ServerFactory.install(Server)
about defaultServers
builtIn TimerServer
new Event(false) // will not support defaultServers(TimerServer)