Most recent form

_form.html.erb

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

      <ul>
        <% @post.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 :content %>
    <br/>
    <%= f.text_area :content %>
  </div>
  <div class="field">
    <%= f.label :category %>
    <br/>
    <%= f.text_field :category %>
  </div>

  <div class="field">

    <%= f.fields_for :attachments do |attach| %> <br>
      <%= attach.file_field :photo %> <br>
      <%= attach.collection_select :category_id, AttachmentCategory.all, :id, :name %>
    <% end %>

    <br>
  </div>

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