Select checkbox pass array in ruby on rails

Question

How can I pass the value of array? of the selected checkbox.

In View:

= check_box_tag 'user_message_ids[]', user_message.id, false

= link_to "<button>Bulk Delete</button>".html_safe, profile_message_path(user_message), :id => 'user_message_ids', :confirm => "Are you sure?", :method => :delete

and can I place the submit button in any of this area.

like this one:

= form_tag checked_messages_path do
  = check_box_tag 'user_message_ids[]', user_message.id, false
--------objects---------------------------------------------
--------objects---------------------------------------------
--------objects---------------------------------------------
--------objects---------------------------------------------
= submit_tag "Delete Checked"

Answer 1

Use a form_tag block

<% form_tag delete_mutiple_items_path do %>
  <table>
    <thead>
      <tr>
        <th></th>
      </tr>
    </thead>
    <tbody>
      <% @items.each do |item| %>
      <tr>
        <td><%= check_box_tag "items[]", item.id %></td>
      </tr>
      <% end %>
    </tbody>
  </table>
  <%= submit_tag "delete Checked" %>
<% end %>

It will pass an array of ids to controller, like {"item_ids[]" => ["1", "2", "3"]}

So you can do anything with these ids

FYI: http://railscasts.com/episodes/165-edit-multiple?view=asciicast

Updated (One Small Gotcha)

From here: http://railscasts.com/episodes/17-habtm-checkboxes?view=asciicast

There is still one small problem with our update method. If we uncheck all of the checkboxes to remove a product from all categories then the update fails to remove any categories the product was in. This is because a checkbox on an HTML form will not have its value sent back if it is unchecked and therefore no category_ids will appear in the product’s parameters hash, meaning that the category_ids are not updated.

To fix this we have to modify our products controller to set the category_ids parameter to be an empty array if it is not passed to the update action. We can do this using Ruby's ||= operator and add the following like at the top of the update action.

params[:product][:category_ids] ||= []

This will ensure that if none of the checkboxes are checked then the product is updated correctly so that it is in no categories.