module-and-template-store/app/views/extensions/_form.html.erb

<%= form_for(@extension) do |f| %>
  <% if @extension.errors.any? %>
    <div id="error_explanation">
      <h2><%= pluralize(@extension.errors.count, "error") %> prohibited this extension from being saved:</h2>

      <ul>
      <% @extension.errors.full_messages.each do |msg| %>
        <li><%= msg %></li>
      <% end %>
      </ul>
    </div>
  <% end %>

  <div class="field">
    <%= f.label :title %><br>
    <%= f.text_field :title %>
  </div>
  <div class="field">
    <%= f.label :author %><br>
    <%= f.text_field :author %>
  </div>

  <div class="field">
    <%= f.label :description %><br>
    <%= f.text_area :description %>
  </div>

  <label>Preview</label>
    <%= f.file_field :preview %>
    <%= f.hidden_field :preview_cache %>
  </p>

  <p>
  <label>Module</label>
    <%= f.file_field :extension %>
    <%= f.hidden_field :extension_cache %>
  </p>

  <div class="actions">
    <%= f.submit %>
  </div>
<% end %>