title: How to pass extra parameter in rails form_for
body: <p>How I can get <code>redirect_id</code> from this form?</p>
  
  <pre><code>&lt;%= form_for(@category) do |f| %&gt;
   &lt;%= hidden_field_tag :redirect_id, :value=&gt;5 %&gt;
   &lt;%= f.text_field :text %&gt;
  &lt;% end %&gt;
  </code></pre>
  
  <p>In controller I can get only <code>category</code> params in my <code>params</code> array.</p>
  
  <p>Maybe because I'm using only this code to filter parameters in controller.</p>
  
  <pre><code>def panel_category_params
    params.require(:category).permit(:text)
  end
  </code></pre>