Writing Async code in event driven way

Question

I am programminfg in node.js sometimes async functions become really incredibly dirty. I want to write async code but retrieve data as an event happens i am aware of promises but it is not exactly what i want simply what i ask is something like this

asyncFunc(error,dt,ld){
//some async code such as db operations
}

then i want to fetchj the data in event way

asyncFunc.on("dt",function(dt){do something});
asyncFunc.on("error",function(err){i have an error object});
asyncFunc.on("ld",function(ls){loading});

is there any way to do this i know promises and some 3rd party libraries against callback hell but my question is especially in that way i wrote how i can design my code ?

Answer 1

Use nodejs events

var asyncFunc = function(error,dt,ld){
    var events = require('events');
    var eventEmitter = new events.EventEmitter();

    //emit error
    eventEmitter.emit('error', new Error('some error'));
    //emit dt
    eventEmitter.emit('dt', 'some data for dt');
    //emit dld
    eventEmitter.emit('ld', {message: 'some details for ld', ld: ld});
    return eventEmitter;
}

//then
asyncFunc.on("dt",function(dt){/*do something*/});
asyncFunc.on("error",function(err){/*i have an error object*/});
asyncFunc.on("ld",function(ls){/*loading*/});

Great article here
Official nodejs event docs