Rails Render of Partial and Layout in Controller

Render :partial with :layout don't work in view

Instead of using

<%= render :partial => 'partial_test', :layout => 'partial_test' %>

what i needed to use was

<%= render :partial => 'partial_test', :layout => 'layouts/partial_test' %>

Rails render of partial and layout in controller

Partial rendering in a controller is most commonly used together with Ajax calls that only update one or a few elements on a page without reloading. Rendering of partials from the controller makes it possible to use the same partial template in both the full-page rendering (by calling it from within the template) and when sub-page updates happen (from the controller action responding to Ajax calls). By default, the current layout is not used.

This may be the reason your code is not working you can use rendering template.

Template rendering works just like action rendering except that it takes a path relative to the template root. The current layout is automatically applied.

if resource.company_form
   render :template => "shared/company_signup_form"
else
   render :template => "shared/individual_signup_form"   
end

** REMOVE UNDERSCORE from your partail name because you are using this as a template.

Hope this works !

Render a partial layout in rails

First of all - always downcase on file names! Never use Design or MyCoolStory, in rails we use convention over configuration and that means snake_case which is everything downcased and separated with _under_scores

To your render issues:
There is a great documentation where you'll find anything you need: http://guides.rubyonrails.org/layouts_and_rendering.html

Let me help you a little.

Rails is looking for a Layout. By default it will be expected in /app/views/layouts/application.html.erb (there is nothing wrong with keeping it named as application). A Layout is the whole HTML Frame you will need. Within the Layout there (should) always be a yieldblock.
A YieldBlock in rails is where your templates are rendered into.

so basically a layout-file can look like this (i use haml for easier reading)

%html
  %head
    =render "shared/head"
  %body
    .wrapper
      %nav.navigation=render "shared/navigation"
      .main_content
        =yield
      %footer.foot=render "shared/footer"

This means you are having 3 partial-templates in /app/views/shared named _head.html.erb, _navigation.html.erb and _footer.html.erb

That's the rails way.

Further informations

If you are planning to have a multi-design app, you should structure your views in total like

/app/views/design1
/app/views/design2
/app/views/design3
/app/views/shared

and set the lookup path in your controller like this

prepend_view_path "#{Rails.root}/app/views/#{design_path}"
def design_path
  current_page.design_name
end

By then, all views will be looked up into their specified folder (Spree multi_store engine, is doing like this, for an example)

Rails render partial from controller

The better way would be to call the partials from index.html.erb

<% unless params[:check].nil? %>
  <%= render :partial => '/layout/check' %>
<% else %>
  <%= render :partial => '/layout/not_check' %>
<% end %>

so your def index would look like this

def index
  respond_to do |format|
    format.html
  end
end

I did not understand what you are trying to do but partial which are related to controller/actions should not be in layout unless they are serving some layout.

Render :layout is searching for partial instead of layout

render works differently in controllers than it does in views. In controllers, it's primarily for rendering action templates, while in views, it's primarily for rendering partial templates. When you want to render a specific layout for an action, you have a few options, but all of them are in the controller.

If you want every action in a particular controller to use that layout, you can either specify layout 'something' in that controller (usually near the top) or for a ApplesController, you can create a new layout in app/views/layouts/apples.html.erb and this will automatically be used as the default layout for the ApplesController.

If you want just a single action in a controller to use that layout, you can use your render layout: 'something' inside of a controller action, where the action to render is implied to be the current action.

Links from the Rails docs:

Action Rendering
Partial Rendering
Nested Layouts

how to render partial on everything except a certain action

Replace your render with this:

<%= render 'layouts/header' unless @disable_nav %>

Then you can simply set disable_nav to true in any controller action you like:

def landing_page
  @disable_nav = true
end

As a before_filter, which I'd encourage over the above:

application_controller.rb

def disable_nav
  @disable_nav = true
end

my_controller

before_filter :disable_nav, only: [:landing_page]

Rendering a partial in rails, in two separate places, from two different controllers

Should be with an equal sign: <%= render ... %>.

<% %> executes Ruby code, but does not render a result. Whereas <%= %> executes and renders.

Rails 5: Rendering a partial to the application layout

(migrating from comments)

What if you created a show.html.erb for that controller and placed render :partial there? It should work.

Explanation: Partials are to be used from "big" views. So, they are not wrapped in the layout on purpose!