NestedLayouts

Plugin allows to specify outer layouts for particular layout thus creating nested layouts.

Wrapping layout into another layout

Let’s assume you have controller which action ‘hello’ just was called. Controller was set up to use ‘inner’ layout:

  app/controllers/hello_controller.rb

    class HelloController < ApplicationController
      layout 'inner'

      def hello
        render :text => 'Hello, world!'
      end
    end

  app/views/layouts/inner.rhtml

    <% inside_layout 'outer' do -%>
      <div class="hello">
        <h1>Greetings</h1>
        <%= yield %>
      </div>
    <% end -%>

  app/views/layouts/outer.rhtml

    <html>
    <body>
      <div class="content">
        <%= yield %>
      </div>
    </body>
    </html>

Result will look like this (formatted for better reading):

    <html>
    <body>
      <div class="content">
        <div class="hello">
          <h1>Greetings</h1>
          Hello, world!
        </div>
      </div>
    </body>
    </html>

Concept

Concept of layout nesting here is based on the assumption that every inner layout is used only to customize it’s outer layout and thus every inner layout is used only with one specific outer layout. With this in mind we can conclude that every layout must know it’s outer layout and thus information about outer layout must be embeded directly into inner layout. Controller doesn’t need to know about the whole stack of layouts, so you should just specify the most inner layout in it.

Passing data

You can pass data from inner layout to outer one, e.g.:

  layouts/inner.rhtml

    <% content_for 'menu' do -%>
      <ul>
        <li><a href="about_us">About Us</a></li>
        <li><a href="products">Products</a></li>
      </ul>
    <% end -%>

    <% inside_layout 'outer' do -%>
      <% @other_data_for_outer_layout = 'foo' -%>
      <%= yield %>
    <% end -%>

  layouts/outer.rhtml

    <%= yield 'menu' %>
    <br/>
    The data was: <%= @other_data_for_outer_layout %>
    <br/>
    <%= yield %>

Download

Download it from rubyforge.org/projects/nested-layouts/ or install it via Rails plugin script:

  ./script/plugin install svn://rubyforge.org/var/svn/nested-layouts/trunk/nested_layouts

Bugs & Feedback