'onChange' callback delayed until user stops changing value of input

wait_for_it.coffee

# Calls callback function if value of given element stops changing
#
# elem - element which's value we're watching
# callback - anonymous method or callback fuction name
# (delay) - delay before callback 
wait_for_it = (elem, callback, delay = 750) ->
  old_val = elem.val()

  setTimeout ( ->
    if elem.val() == old_val
      callback()
    ), delay
    
# Usage example:
$('input').change ->
  wait_for_it($(this), ->
    alert('foo!')
  )