Checkbox -> hide/show element


this is probably an easy question: I have a checkbox and a datetime
field in a form. This is what I want to achieve:

1) in default mode the checkbox is unchecked and the datetime field is
2) when the user marks (clicks) the checkbox (so it is checked) the
datetime field is shown

This is what I have in my view (very close to it):

<% form_for(logentry, :url => @url, :method => @method) do |f| %>
  <%= f.error_messages %>
    <tr><td class="key"><%= f.label :mycheckbox, "Remind me?"
%></td><td><%= f.check_box :mycheckbox %></td></tr>
   <tr id="hideshow"><td class="key"><%= f.label :remind_when,
"Date"%></td><td><%= datetime_select "logentry","remind_when", :default
=> %></td></tr>
    <%= f.submit submit_name %>
<% end %>

Where should I sprinkle the javascript? Do I need to create another
action in my controller (show_element/hide_element) with rjs code? Or is
there something like onclick => "show element hideshow"?



I don't like self-answered posts...

I've found a solution. I have created a simple javascript:

<script type="text/javascript">
  function switchvisibility(el) {
    if (document.getElementById(el).checked) {
      document.getElementById('wvdatetime').style.display = "table-row";
    } else {
      document.getElementById('wvdatetime').style.display = "none";

my checkbox in the form has
:id => "thiselement", :onchange => "switchvisibility('thiselement')"

and the table row I want do hide has:
<tr id="wvdatetime" style="display: none;"> ....</tr>

That's it. I hope the solution is not too stupid.


That's fine, but Rails normally includes the prototype libs, so you
could have done it in one line:

:onclick => "ELEMENT_NAME.hide();return false"