async_script.html

<script type='text/javascript'>// <![CDATA[
  (function(){
      var e = document.createElement('script'); e.type = 'text/javascript'; e.async = true;
      e.src = "//www.pagebox.es/assets/embeds/parent.js";
      (document.getElementsByTagName('head')[0] || document.getElementsByTagName('body')[0]).appendChild(e);
  })();
// ]]></script>

<iframe src="//www.pagebox.es/embeds/e8a63cb2f8ef466d7dbae65fa5ac4f1190151189" data-pagebox-id='e8a63cb2f8ef466d7dbae65fa5ac4f1190151189' frameborder='0' scrolling="no" style="width:100%; overflow:hidden;"></iframe>

helper.rb

module CollectionsHelper
  def html_embed_code(node)
    <<-EOS
    <script type='text/javascript'>// <![CDATA[
      (function(){
          var e = document.createElement('script'); e.type = 'text/javascript'; e.async = true;
          e.src = "//#{default_host_with_port}#{asset_path('embeds/parent.js', :digest => false)}";
          (document.getElementsByTagName('head')[0] || document.getElementsByTagName('body')[0]).appendChild(e);
      })();
    // ]]></script>
    <iframe src="//#{default_host_with_port}/embeds/#{node.token}" data-pagebox-id='#{node.token}' frameborder='0' scrolling="no" style="width:100%; overflow:hidden;"></iframe>
    EOS
  end
end

other_async_script.html

<script type='text/javascript'>// <![CDATA[
  (function(){
      var window.Pagebox ={};
      Pagebox.id = 'e8a63cb2f8ef466d7dbae65fa5ac4f1190151189';
      
      var e = document.createElement('script'); e.type = 'text/javascript'; e.async = true;
      e.src = "//www.pagebox.es/assets/embeds/parent.js";
      (document.getElementsByTagName('head')[0] || document.getElementsByTagName('body')[0]).appendChild(e);
  })();
// ]]></script>

view.haml

%textarea.disabled.form-control.mb30{readonly:"readonly", onclick:"this.select()", rows:3}
  = html_embed_code(@node)