Rails conditional sidebar in application layout

Question

The following is my application layout file

  .container_12.clearfix
  = render :partial => 'shared/flashes'

  .grid_8
    = render :partial => 'shared/search'        
    = yield
  .grid_4
    = yield(:sidebar)

It has to grids, one for content and another for sidebar. Now I'm creating a login page in which I don't want to show my sidebar(just the single grid. I can simply create new layout with the .grid_12 div as the single grid.

But this leaves me with 2 app layouts. How can I make the same application layout conditional to yield sidebar?

If with sidebar, it would be same as above else just a single .grid_12 like the one below

  .container_12.clearfix
  = render :partial => 'shared/flashes'      
  .grid_12
    = render :partial => 'shared/search'        
    = yield

Answer 1

Why not use an if condition based on an instance variable set in you controller. Your default looks like it should render with sidebar. So the following code will only render without sidebar, if you've set @disable_sidebar to anything but false or nil.

.container_12.clearfix
= render :partial => 'shared/flashes'
- unless @disable_sidebar
  .grid_8
    = render :partial => 'shared/search'        
    = yield
  .grid_4
    = yield(:sidebar)
- else
  .grid_12
  = render :partial => 'shared/search'        
  = yield

Answer 2

You can check if a content for :sidebar exists and render the sidebar if true. Rails 2.3.5 will have a content_for? method. In the meantime, you can use my Helperful Gem.

- if has_content?(:sidebar)
  .grid_8
    = render :partial => 'shared/search'        
    = yield
  .grid_4
    = yield(:sidebar)
- else
  .grid_12
  = render :partial => 'shared/search'        
  = yield

Otherwise, you can assume if :sidebar == false then no sidebar.

  def sidebar(enable = true, &block)
    if enable
      content_for :sidebar, &block
    else
      @fullpage = true
    end
  end

  def fullpage?
    !!@fullpage
  end

- if fullpage?
  .grid_12
  = render :partial => 'shared/search'        
  = yield
- else
  .grid_8
    = render :partial => 'shared/search'        
    = yield
  .grid_4
    = yield(:sidebar)