Creating Callbacks for required modules in node.js

Question

Is there any possibilitie for creating some kind of a callback within a module created by my own?

My problem is that I have written a module for my application. With

Answer 1

The call back syntax:

function start(callback)
{


    //do some tasks

    callback(data);
}

exports.start = start;

Anywhere you require your module:

var mymod = require("./mymod.js");

mymod.start(function(data) {
   //do some tasks , process data

});

Answer 2

Yes, you can have a callback from your module.

It's as simple as

function funcWithCallback(args, callback){
    //do stuff

    callback();
}

While I don't know what you are trying to accomplish, the while loop looks suspicious. You probably should invest in the async package from npm.

async on github

EDIT: I felt the need to clarify something. While the above function does in fact intend the callback is used instead of the return value, it's not exactly async.

The true async approach is to do something like this:

function funcWithCallback(args, callback){      
    process.nextTick(function() {
        //do stuff
        callback();
    });     
}

This allows the called function to exit and defers the execution of the logic of that function until the next tick.