ruby-on-rails - If yield is a closure inside a layout, then how does layouts are rendered within?

Question

In Rails, if yield is a closure inside a layout, then how does controller can dictate which layout to render?

layout :render => "myLayout"

Answer 1

控制器中的layout命令也可以接受一个符号，它将它链接到一个方法。像这样：

class ApplicationController < ActionController::Base

  layout :layout_by_resource

  protected

  def layout_by_resource
    if devise_controller? && resource_name == :admin_user
      "devise_admin"
    else
      "application"
    end
  end

end

因此，您可以使用它从控制器中切换出要使用的布局。

Answer 2

如果要为控制器设置布局

class YourController < ApplicationController
  before_filter :set_layout

  protected

  def set_layout
    render :layout => 'Your-layout'
  end
end