Rails ActiveAdmin. How to set default value?
<p>I have code like this:</p>

<pre><code>ActiveAdmin.register Post do

form do |f|
  f.inputs "Post Details" do
    f.input :title
    f.input :body
    f.input :published_at, :as =&gt; DateTime.now
  end
  f.actions
end
</code></pre>

<p>I want the field <code>:published_at</code> (which is t.datetime) to be set to the current date and time by default. My example doesn't work. How can I achieve this?</p>