USA phone formating

phone.coffee

format_phone = (phone, convert, trim) ->
  convert = true  if typeof convert is "undefined"
  trim = true  if typeof trim is "undefined"
  
  # Strip out any extra characters that we do not need only keep letters and numbers
  phone = phone.replace(/[^0-9A-Za-z]/, "")
  
  # Do we want to convert phone numbers with letters to their number equivalent?
  if convert is true and phone.match(/[a-zA-Z]/)
    replace =
      2: ["a","b","c"]
      3: ["d","e","f"]
      4: ["g","h","i"]
      5: ["j","k","l"]
      6: ["m","n","o"]
      7: ["p","q","r", "s"]
      8: ["t", "u","v"]
      9: ["w","x","y","z"]

    
    # Replace each letter with a number
    # Notice this is case insensitive with the str_ireplace instead of str_replace 
    for digit of replace
      regex = new RegExp("[" + replace[digit].join("") + "]", "ig")
      phone = phone.replace(regex, digit)
  
  # If we have a number longer than 11 digits cut the string down to only 11
  # This is also only ran if we want to limit only to 11 characters
  phone = phone.substr(0, 11)  if trim is true and phone.length > 11
  
  # Perform phone number formatting here
  if phone.length is 7
    return phone.replace(/([0-9a-zA-Z]{3})([0-9a-zA-Z]{4})/, "$1-$2")
  else if phone.length is 10
    return phone.replace(/([0-9a-zA-Z]{3})([0-9a-zA-Z]{3})([0-9a-zA-Z]{4})/, "($1) $2-$3")
  else return phone.replace(/([0-9a-zA-Z]{1})([0-9a-zA-Z]{3})([0-9a-zA-Z]{3})([0-9a-zA-Z]{4})/, "$1($2) $3-$4")  if phone.length is 11
  
  # Return original phone if not 7, 10 or 11 digits long
  phone