Trying to render a view from a different controller.But I get to the..

In my app, I have created a form to create new posts (Post is a model). I have a controller with the name posts. The form is located in the admins controller. The form use the form_for(@post). It post to the post controller. In this method, the post gets created successfully. But the problem is with failed submissions. In the form, I have added the code to show the errors

        <% if @post.errors.any? %>
          <div id="error_explanation">
              <div class="alert alert-error">
                The form contains <%= pluralize(@post.errors.count, "error") %>
              </div>
              <ul>
                <% @post.errors.full_messages.each do |msg| %>
                  <li> <%= msg %> </li>
                <% end %>
              </ul>
          </div>
        <% end %>

But in the post controller, if there's a failed submission, I have set it to redirect_to the newpost page in the admins controller. When redirecting, I will loose the error messages.

So, I added

    render 'dasharea/newpost'

localhost:3000/dasharea/newpost is the URL of the page that have the form. With this code, it say

    Missing template dasharea/newpost with {:locale=>[:en], :formats=>[:html], :handlers=>[:erb, :builder, :coffee]}.

But Im already in that page? Then I tried to add the controller and the action like this (note: im editing the create action of posts controller. I need to render the newpost action in admins controller) :

    render 'admins/newpost'

Then, it will direct me to the posts :

    http://localhost:3000/posts

But now, the form is there and I can see the errors. But I need to render the oroginal page which I have the form (dasharea/newpost)! How can I do this? What have I done wrong?