Ruby On Rails, client side validation, does not work with form_tag

Question

My client side validation doesnt work somehow.

My html.erb:

 <%= form_tag what_to_do_file_path, method: :get do %>
                          <%= submit_tag "Delete selected", :commit =>"delete" %>
                          <%= submit_tag "Pictures/Info/Raw Int", :commit =>"pictures" %>
                          <%= submit_tag "File normalize", :commit =>"pictures" %>

                          <%= form_for Group.new, :validate => true do |f| %>
                             <div class="field_label">
                             <%= f.label :group_name%>:
                             </div>
                             <div class="field">
                             <%=f.text_field :group_name %>
                             </div>
                          <%end%>
         <% @files.each do |file| %>

         <p><td> <%= check_box_tag "files[]", file.id %></td><%= file.file_name %></p>
        <%=end%>
<%=end%>

My controller:

class Group< ActiveRecord::Base
  include ActiveRecord::Validations
   attr_accessible  :group_name
   validates :group_name,                   
                                     :uniqueness => { :case_sensitive => false}

end

I what_to_do action I catch the ids of the files, that I want to group and params[:commit], meaning what I want to do with the files in this group.
Example
File 1, File 2, File 3. I select all those Files and type a group name "Tripple" and select what I want to do with this group (either File normalize or whatever..) (The name of the group should be validated in case this group already exists, in what_to_do I want to catch the ids of the files, params[commit] and the group name)

The validation works if I put a form_for outside form_tag, but I need to have it in form_tag because I want to catch in what_to_do action the name of the group.
How can I do it?

Answer 1

why aren't you using

form_for :something, url: what_to_do_file_path, method: :get  

it is always encouraged to use form_for for this kinda tasks