Checkboxes on Rails

问题

What's the correct way of making checkboxes that are related to a certain question in Ruby on Rails? At the moment I have:

<div class="form_row">
    <label for="features[]">Features:</label>
    <br><%= check_box_tag 'features[]', 'scenarios' %> Scenarios
    <br><%= check_box_tag 'features[]', 'role_profiles' %> Role profiles
    <br><%= check_box_tag 'features[]', 'private_messages' %> Private messages
    <br><%= check_box_tag 'features[]', 'chatrooms' %> Chatrooms
    <br><%= check_box_tag 'features[]', 'forums' %> Forums
    <br><%= check_box_tag 'features[]', 'news' %> News
    <br><%= check_box_tag 'features[]', 'polls' %> Polls
</div>

I also want to be able to automatically check the previously selected items (if this form was re-loaded). How would I load the params into the default value of these?

回答1:

You are looking at the following:

<div class="form_row">
    <label for="features[]">Features:</label>
    <% [ 'scenarios', 'role_profiles', ... , 'polls' ].each do |feature| %>
      <br><%= check_box_tag 'features[]', feature,
              (params[:features] || {}).include?(feature) %>
      <%= feature.humanize %>
    <% end %>
</div>

Although if you already have a Feature model, with a features table and a has_many :features relationship, you probably want this:

<div class="form_row">
    <label for="feature_ids[]">Features:</label>
    <% for feature in Feature.find(:all) do %>
      <br><%= check_box_tag 'feature_ids[]', feature.id,
              @model.feature_ids.include?(feature.id) %>
      <%= feature.name.humanize %>
    <% end %>
</div>

来源：https://stackoverflow.com/questions/621340/checkboxes-on-rails