Question

I am running a web page from a server using webrick. How can I capture an event from the web browser? I do not want to do it through JavaScript, but I want to get a response through webrick, and process it in ruby, perhaps using one of the do_... methods. If JavaScript is minimally needed, that is okay. I do not want to redirect to a different page.
I do not know what to put in the value for an event (like onclick).

<input type=button onclick="..." value="Press Me">

Answer 1

After struggling, with the help of this page, I seem to have gotten close to what I wanted:

xxx.html

<input type="button" value="Click me" onclick="onclick('value to pass');" />

xxx.js

function onclick(v){
  e=new XMLHttpRequest();
  e.open("GET", "http://localhost:3000?t=0&"+v, true);
  e.onreadystatechange=function(){if (e.readyState==4 && e.status==200){
    // some code to rewrite if necessary
  };};
  e.send();
}

xxx.rb

class WEBrick::HTTPServlet::AbstractServlet
  def do_GET request, response
    # some code to process the request
    response.body = a_return_string_for_rewriting
    response.status = 200
  end
end