How to pass a variable to a layout?

Question

I have a two versions of my application layout, which are differs only in a few lines. Consider following example:

!!!    
%html
    %head
        # a lot of cod         


        

Answer 1

There is two another option to do, what actually the OP asked:

#1

in your layout:

- if flag ||= false
  # variant 1
- else
  # variant 2

in your application controller (this is the trick):

layout 'application' # or whatever

in any kind of controller:

render :locals => { :flag => true }

My guess would be, the layout processing is happening later cause of the "dynamic" (not really) layout definition and that generates the necessary methods for all the keys inside of local_assigns. So maybe the instance variable is a performanter solution. Any thoughts about that? Please leave a comment.

#2

You could just use the local_assigns variable like:

- if local_assigns[:flag] ||= false
  # variant 1
- else
  # variant 2

and then in any of your controller:

render :locals => { :flag => true }