Question

In the following code, I’m trying to get mydata passed to the callback. This is a sample problem from a bigger problem I’m having. I’m assuming this is a scope issue. What is wrong with my code and/or what should I do?

var EventEmitter = require('events').EventEmitter;
var myevent      = new EventEmitter();
var mydata       = 'my data!';

function myfunc (data, mydata) {
  console.log(data);
  console.log(mydata);
};

myevent.on('data', function(data, mydata) {myfunc(data,mydata)});

myevent.emit('data', "data!");

returns:

data!
undefined

I’d like it to return:

data!
my data!

Answer 1

i’m going to make a wild guess (since i am not familiar with EventEmitter) and say that emit‘s first parameter is the name of the event, and the remaining parameters are passed to the handler.

if that is the case, you’re not passing anything to the second callback parameter, which is why it comes in as undefined. try this instead:

myevent.emit('data', "data!", "mydata!");

note: i am ignoring your shadowing issue as it is not related to the problem, just a bad practice.