#125 Dynamic Layouts

Sep 01, 2008 | 11 minutes | Views, Controllers, Plugins

Discover how to dynamically change the layout using content in the database. Check out this episode for details.

Download:
source codeProject Files in Zip (113 KB)
mp4Full Size H.264 Video (18.9 MB)
m4vSmaller H.264 Video (12.7 MB)
webmFull Size VP8 Video (33 MB)
ogvFull Size Theora Video (26.3 MB)

Resources

          bash
        
script/generate migration add_layout_to_blogs layout_name:string custom_layout_content:text
rake db:migrate
gem install liquid

          controllers/application.rb
        
def load_blog
  @current_blog = Blog.find_by_subdomain(current_subdomain)
  if @current_blog.nil?
    flash[:error] = "Blog invalid"
    redirect_to root_url
  else
    self.class.layout(@current_blog.layout_name || 'application')
  end
end

          config/environment.rb
        
config.gem 'liquid'

          layouts/custom.html.erb
        
<%= Liquid::Template.parse(@current_blog.custom_layout_content).
      render('page_content' => yield, 'page_title' => yield(:title)) %>

          blogs/_form.html.erb
        
<p>
  <%= f.label :layout_name %><br />
  <%= f.select :layout_name, [["Standard", 'application'], ["Plain", 'plain'], ["Custom", 'custom']] %>
</p>
<p>
  <%= f.label :custom_layout_content %><br />
  <%= f.text_area :custom_layout_content, :rows => 12 %>
</p>

Full Source Code

UPDATE: As Pratik mentioned in the comments, the above code is not thread safe. Here is a better way to handle the layout which is thread safe.

          application.rb
        
layout :set_layout

def load_blog
  @current_blog = Blog.find_by_subdomain(current_subdomain)
  if @current_blog.nil?
    flash[:error] = "Blog invalid"
    redirect_to root_url
  end
end

def set_layout
  (@current_blog && @current_blog.layout_name) || 'application'
end