Redmine/app/views/projects/list_documents.rhtml

<div class="contextual">
<%= link_to_if_authorized l(:label_document_new),
                          {:controller => 'projects', :action => 'add_document', :id => @project},
                          :class => 'icon icon-add',
                          :onclick => 'Element.show("add-document"); return false;' %>
</div>

<div id="add-document" style="display:none;">
<h2><%=l(:label_document_new)%></h2>
<% form_tag({:action => 'add_document', :id => @project}, :class => "tabular", :multipart => true) do %>
<%= render :partial => 'documents/form' %>
<div class="box">
<%= render :partial => 'common/attachments_form'%>
</div>
<%= submit_tag l(:button_create) %>
<%= link_to l(:button_cancel), "#", :onclick => 'Element.hide("add-document")' %>
<% end %>
</div>

<h2><%=l(:label_document_plural)%></h2>

<% if @documents.empty? %>
<p class="nodata"><%= l(:label_no_data) %></p>
<% end %>

<% documents = @documents.group_by {|d| d.category } %>
<% documents.each do |category, docs| %>
    <h3><%= category.name %></h3>
    <%= render :partial => 'documents/document', :collection => docs %>
<% end %>