event-emitter-lite

npm install event-emitter-lite

use

import to use

let eventemitter = require("event-emitter-lite");

API

let onTest = new eventemitter.EventEmitter();

subscribe

onTest.subscribe(msg => console.log(msg));

once

onTest.once(msg => console.log(`One more time: ${msg}`));

cancel the next call

let egoistSubscribe = onTest.subscribe(msg =>{
    console.log(`the Dalek sad: ${msg}`);
    onTest.cancel();
});

onTest.subscribe(msg => console.log(`Im not a Dalek: ${msg}`));

emit

onTest.emit('go go go!!!');

unsubscribe

onTest.unsubscribe(egoistSubscribe);

cancel a event

onTest.cancel();

cancel a subscribe

egoistSubscribe.cancel();

emit again and again ....

onTest.emit('go go go!!!');

getting emitted value

onTest.emit('last chance...');
console.log(`Would it recieve the last msg? ${onTest.emittedValue}`); 
//yes :)

working with errors

with javascript

let onTest = new eventemitter.EventEmitter();
onTest.subscribe(
    msg => console.log(msg)
    , err => console.log(err)
);

onTest.error('It´s is a multiverse erro!');

with typescript

let onTest = new EventEmitter<string,string>();
onTest.subscribe(
    msg => console.log(msg)
    , err => console.log(err)
);

onTest.error('It´s is a multiverse erro!');

emiting a value (can do a promise) after a emit

onTest.subscribe(msg => 'finished!');

let afterEmit = onTest
    .emit('its ok');
    // ['finished!']

with promise

onTest.subscribe(msg => {
    //...do any thing with 'msg';
    return new Promise(sucess => {
        setTimeout(() => sucess('finished!'),2000);
    });
});

Promise.all(
    onTest
        .emit('its ok')
)    
.then(() => console.log('finish!!!'));