An error of Missing template

I use observe_form to monitor a form, whenever a field changed in this form, an (Missing template builder/update_make_view_info.js.erb...) error will be thrown. I don't want to use js format. I want to use html.erb format. How can I avoid it and why it looks for update_make_view_info.js.erb? This is my action code:

def update_make_view_info     ...     render :patial=>'project_version' end

I would be interested in running a template engine to create output in any xml-format from Ruby/JRuby. I think using the <%..%> notation of rails would do, but I don't want this to go to the web, but rather keep it in the file system as output.

Best regards

Karl