Hello!

I have watched Railscast about strong_parameters,
http://railscasts.com/episodes/371-strong-parameters (sorry, for
subscribers only), and implemented that solution.

Author suggested to filter out forbidden attributes. And it is really
needed, because strong_parameters will not raise exception on attempt to
change forbidden attribute. Success message will be displayed to user, but
attribute will stay unchanged. It is expected behaviour
(https://github.com/rails/strong_parameters/issues/54#issuecomment-977...)

So, that Railscast's code to filter out forbidden attribute is:

<% if permitted_params.topic_attributes.include? :sticky %>
<div class="field">
  <%= f.check_box :sticky %>
  <%= f.label :sticky %>
</div>
<% end %>

Using simple_form it can be written like this:

<%= f.input :sticky, :as => :boolean if
permitted_params.topic_attributes.include?(:sticky) %>

It's already too much I think. But it is only one attrbute. For five
attributes it will be five permitted_params.topic_attributes.include?()

It probably can be shortened, but still there is a need to specify some
condition for each attribute to filter out forbidden ones.

So maybe simple_form gem is the right place to auto-apply strong_parameters
permissions? Or there is another way to do it?