How to pass a Javascript variable to Rails Controller?

Question

Inside my index.html.erb

i need pass this var msg to

Answer 1

Try this

<%= link_to_remote, 'Message', :url=>{:controller=>'controller_name', :action=>'method_name'}, :with=> "'msg='+msg" %>

controller_name.rb

def method_name
  @message= params[:msg]
  puts @message # >> should be print "Hello World"

end

EDITED

<%= link_to_remote, 'Message', :url=>{:controller=>'controller_name', :action=>'method_name'}, :with=> "'msg='+msg" %>
<div id ='show_message'></div>

controller_name.rb

def method_name
  @message= params[:msg]
  render :update do|page|
    page.replace_html 'show_message', @message
  end
end