Creates a debounced function that delays invoking func until after wait milliseconds have elapsed since the last time the debounced function was invoked. The debounced function comes with a cancel method to cancel delayed func invocations and a flush method to immediately invoke them. Provide an options object to indicate that func should be invoked on the leading and/or trailing edge of the wait timeout. Subsequent calls to the debounced function return the result of the last func invocation.

Note: If leading and trailing options are true, func is invoked on the trailing edge of the timeout only if the the debounced function is invoked more than once during the wait timeout.

See David Corbacho's article for details over the differences between _.debounce and _.throttle.

// avoid costly calculations while the window size is in flux
jQuery(window).on('resize', _.debounce(calculateLayout, 150));

// invoke `sendMail` when the click event is fired, debouncing subsequent calls
jQuery('#postbox').on('click', _.debounce(sendMail, 300, {
  'leading': true,
  'trailing': false
}));

// ensure `batchLog` is invoked once after 1 second of debounced calls
var source = new EventSource('/stream');
jQuery(source).on('message', _.debounce(batchLog, 250, {
  'maxWait': 1000
}));

// cancel a debounced call
var todoChanges = _.debounce(batchLog, 1000);
Object.observe(models.todo, todoChanges);

Object.observe(models, function(changes) {
  if (_.find(changes, { 'user': 'todo', 'type': 'delete'})) {
    todoChanges.cancel();
  }
}, ['delete']);

// ...at some point `models.todo` is changed
models.todo.completed = true;

// ...before 1 second has passed `models.todo` is deleted
// which cancels the debounced `todoChanges` call
delete models.todo;