dynamic_layout_selection

🧩 Dynamic Layout Selection

You can choose layouts at runtime by passing a symbol or lambda to layout. This enables context-aware layouts (e.g., mobile vs. desktop) without cluttering the controller. Use a lambda that receives the controller instance to decide the layout dynamically.

class ApplicationController < ActionController::Base
  layout ->(controller) {
    if controller.request.format.json?    
      false   # No layout for JSON
    elsif controller.request.user_agent =~ /Mobile/
      "mobile"
    else
      "application"
    end
  }
end

This approach centralizes layout logic and adapts to different request properties seamlessly.