source/app/views/versions/diff.rhtml

<% @heading = 'Compare Versions' %>
<% @overview =  "This page shows changes between versions of #{link_to_page(@version.page)} in #{link_to_site(@wiki)}" %>


<% tabular_form_for :version, nil, :html => {:method => 'get'} do |f| %>
    <tr><th>Source Version</th><td><%= f.select :version_id, @versions.collect { |v| [ v.version_text, v.id ] } %></td></tr>
    <tr><th>Target Version</th><td><%= f.select :id, @versions.collect { |v| [ v.version_text, v.id ] } %></td></tr>
    <tr><th></th><td><input type="submit" value="Compare"></td></tr>
<% end %>

   <div class="sectionHeading">Differences Analysis</div>
    <div class="sectionContent">
      <table cellpadding="0" cellspacing="0" border="0"
      class="sectionTable">
        <tr valign="top">
          <th scope="row" class="sectionTableHeading">
            Old Version
          </th>
          <td class="sectionTableCell">
           <%= link_to_version2 @version.source_version %> 
          </td>
        </tr>              
        <tr valign="top">
          <th scope="row" class="sectionTableHeading">
            New Version
          </th>
          <td class="sectionTableCell">
            <%= link_to_version2 @version %> 
          </td>
        </tr>
        <tr valign="top">
          <th scope="row" class="sectionTableHeading">
            Differences
          </th>
          <td class="sectionTableCell">
            <p><a href="<%= @version.relpath_to_diff(@version.source_version) %>" target="_blank">Open in a new window</a></p>
            <iframe 
            height = "600"
            src ="<%= @version.relpath_to_diff(@version.source_version) %>"
            width="100%">
            </iframe>
          </td>
        </tr>
      </table>
   </div>
   
<%= render :partial => 'pages/relationships'%>