app/views/feedbacks/_feedback_form.html.erb
<%= bootstrap_form_for (@feedback) do |f| %>
<div class="form-group">
<%= f.hidden_field :channel_id, value: @channel.id %>
</div>
<div class="field">
<%= f.text_field :email, placeholder: "Your e-Mail" %>
</div>
<div class="field">
<%= f.text_field :name, placeholder: "Your Name" %>
</div>
<div class="field">
<%= f.text_area :content, placeholder: "Compose new feedback..." %>
</div>
<%= f.submit "Post", class: "btn btn-primary" %>
<% end %>