Add a JavaScript display to the Home page to count down from 140 characters. (Rails Tutorial, 2nd Ed, Chapter 10, Exercise 7)

Question

This exercise was a bit tricky. Figured I\'d post my solution to see if anyone did it differently or if there\'s anyone who knows a better way.

I\'m not sure on best pra

Answer 1

Here's my coffeescript version based on Adriano's solution. This ignores whitespace, doesn't involve adding empty divs into the view, and also adds an error class once you get to minus numbers.

updateCountdown = ->
  text =  jQuery('#micropost_content').val()
  text = text.replace(/\s/g, '');   
  remaining = 140 - text.length
  jQuery('.countdown').text remaining + ' characters remaining'
  jQuery('.countdown').addClass 'alert alert-error' if remaining < 0
  jQuery('.countdown').removeClass 'alert alert-error' if remaining > 0

jQuery(document).ready ->
  jQuery('#new_micropost').append '<span class="countdown">140 characters remaining</span>'
  jQuery('#micropost_content').change updateCountdown
  jQuery('#micropost_content').keyup updateCountdown
  return