如果选中则更改文本-复选框

Question

I have a checkbox with a explanatory Text:

<%= f.label :is_company do %>
  <%= f.check_box :is_company %>&nbsp;&nbsp; <span>Are you Representing a Company / Organization ?</span>
<% end %> 

I need to change the text (if checkbox is triggered) from Are you Representing a Company / Organization ? to I'm representing a Company / Organization !

Can anyone help me out ?

HTML Output :

<label for="user_is_company">
  <input name="user[is_company]" type="hidden" value="0">
  <input id="user_is_company" name="user[is_company]" type="checkbox" value="1">&nbsp;&nbsp; 
  <span>Are you Representing a Company / Organization ?</span>
</label>

I work in coffeescript

So i made this abomination:

$(document).on "ready page:load", ->
  check = ->
    if input.checked
      document.getElementById("label_cmp").innerHTML = "I am representing a Company / Organization !"
    else
      document.getElementById("label_cmp").innerHTML = "Are you representing a Company / Organization ?"
  input = document.querySelector("input[type=checkbox]")
  input.onchange = check
  check()

but i think its a lot of code, for nothing...

Answer 1

Something like this should work. If it doesn't, have a play and tweak, then come back if you still have trouble.

$(document).on "ready page:load", ->
  $("input#user_is_company").on 'change', ->
    if $(this).is(":checked")
      $("#label_cmp").text("I'm representing a Company / Organization !")
    else
      $("#label_cmp").text("Are you Representing a Company / Organization ?")

Note: there is possibly an even shorter way to do this with jQuery toggle , but I have limited knowledge of JS.

Answer 2

$ ->
  $("#user_is_company").on 'change', ->
      $("#label_cmp").text if $(this).is(":checked") then "I am representing a Company / Organization !" else "Are you representing a Company / Organization ?"

Compiles to...

$(function() {
  return $("#user_is_company").on('change', function() {
    return $("#label_cmp").text($(this).is(":checked") ? "I am representing a Company / Organization !" : "Are you representing a Company / Organization ?");
  });
});

Demo: http://jsfiddle.net/VcFCL/

Some comments on my code choices...

# jquery shorthand form for on-ready wrapper function
# ensures DOM is loaded before executing inner function
$ ->
  # identify elements by ID alone, as ID should be unique on the page
  # listen for `change` event on selected element, and run callback
  $("#user_is_company").on 'change', ->
    # set the text of the label conditionally by the `checked` status of the selected element
    $("#label_cmp").text if $(this).is(":checked") then "I am representing a Company / Organization !" else "Are you representing a Company / Organization ?"