ruby - Globally accessible variable in rails -

i want variable globally accessible whole app. user fill single input field form. saved database , variable accessible anywhere. here have done far.

    class applicationcontroller < actioncontroller::base   # prevent csrf attacks raising exception.   # apis, may want use :null_session instead.   protect_from_forgery with: :exception   before_action :save_page    def save_page     @page_name = params[:page_name ]     test_page_name = pagename.new     test_page_name.name = @page_name     if test_page_name.save       redirect_to(controller: 'template',action: 'templates')     end   end  end 

the form submitted save_page method in applicaitoncontroller , after being saved redirected. because method redirect in case of saved database, giving me problem. how can fix this?

i tried no luck

    class applicationcontroller < actioncontroller::base   # prevent csrf attacks raising exception.   # apis, may want use :null_session instead.   protect_from_forgery with: :exception   before_action :page_name    def save_page     @page_name = params[:page_name ]     test_page_name = pagename.new     test_page_name.name = @page_name     if test_page_name.save       redirect_to(controller: 'template',action: 'templates')     end   end    def page_name     @user_page_name = @page_name   end  end 

but when tried print value of @user_page_name in view got nothing.

class applicationcontroller < actioncontroller::base  # prevent csrf attacks raising exception. # apis, may want use :null_session instead.  protect_from_forgery with: :exception  before_action :page_name  def param_page   @page_name=params[:page_name]  end  def save_page   param_page   test_page_name = pagename.new   test_page_name.name = @page_name   if test_page_name.save     redirect_to(controller: 'template',action: 'templates')   end  end   def page_name    param_page    @user_page_name = @page_name   end  end