Resolve this promise when key on an object is truthy Public domain

whenTruthy.coffee

# Resolve this promise when key on an object is truthy
# Optionally you can pass a timeout when to give up and how frequently to check
# Returns a promise resolved or rejected with the value given
whenTruthy = (key, obj = mediator, timeout = 60000, frequency = 100) ->
  dfd = new $.Deferred

  if obj[key]
    dfd.resolve obj[key]
  else
    giveUp = setTimeout ->
      clearInterval checking
      dfd.reject obj[key]
    , timeout

    checking = setInterval ->
      if obj[key]
        clearInterval giveUp
        clearInterval checking
        dfd.resolve obj[key]
    , frequency

  dfd.promise()

whenTruthy.js

// Converted from CoffeeScript
var whenTruthy = function(key, obj, timeout, frequency) {
  var checking, dfd, giveUp;
  if (obj == null) {
    obj = mediator;
  }
  if (timeout == null) {
    timeout = 60000;
  }
  if (frequency == null) {
    frequency = 100;
  }
  dfd = new $.Deferred;
  if (obj[key]) {
    dfd.resolve(obj[key]);
  } else {
    giveUp = setTimeout(function() {
      clearInterval(checking);
      return dfd.reject(obj[key]);
    }, timeout);
    checking = setInterval(function() {
      if (obj[key]) {
        clearInterval(giveUp);
        clearInterval(checking);
        return dfd.resolve(obj[key]);
      }
    }, frequency);
  }
  return dfd.promise();
};