delay.js

delay.js

var _log_start = Date.now();

/**
 * Helper for logging which prepends a time-offset
 */
function log()
{
  console.log.apply(console, ["["+(Date.now()-_log_start)+"]"].concat(args(arguments)));
}

/**
 * Helper for converting `arguments` object in functions into an Array
 * @param  {arguments} argu
 * @return {Array}
 */
function args(argu)
{
  var args = [];
  for (var i = 0; i < argu.length; i++)
    args.push(argu[i.toString()]);

  return args;
}

/**
 * A wrapper for delaying calls to functions.
 * @param  {function} fn     The function to be called after the delay
 * @param  {integer} timeout The delay timeout
 * @param  {object} obj      [optional] The object that the function is called on
 */
function delay(fn, timeout, obj)
{
  if (obj && typeof fn == "string")
    fn = obj[fn];

  return function() {
    var argv = args(arguments);
    setTimeout(function() {
      fn.apply(obj || null, argv);
    }, timeout);
  }
}

/**
 * This is our target function: the one that we want invoked upon a particular
 * event occuring, such as a client connecting or a HTTP request completing.
 */
function ding()
{
  log("Ding!");
}

/**
 * This is the entry function which will set up the event-triggering mechanisms.
 * In this instance, there event is the function itself being fired, so we
 * simply invoke the callback immediately.
 */
function main() {
  // Something will eventually happen, at which point we want to trigger the callback
  ding();
}


/*
 * Here we optionally add in some delays
 */

var arg = process.argv[2];
if (arg == "debug") {
  ding = delay(ding, 1000);
}

// GOGOGO
main();