passing javascript variable to ruby function call in javascript HAML

Question

I'm using Sinatra, Ruby, HAML, and JavaScript

So I figured out how to call a ruby function in HAML JavaScript

@@layout
%html
    %head
        %title #{@title}
          :javascript
              var retval
              function diff_by_company_id() {
                 retval = "#{ruby_function()}";
              }

However I now need to pass the ruby function a javascript variable and I'm not sure how do it. This is what I tried that obviously doesn't work.

def test(input)
    return "Output Number: "+input.to_s + "!"
end

@@layout
%html
    %head
        %title #{@title}
          :javascript
              var retval
              function diff_by_company_id() {
                 var input = 1;
                 retval = "#{ruby_function("input")}";
              }

instead of passing the value of input, 1, it passes in the string input.

So what i get is: retval = Output Number: input!

What I want is: retval = Output Number: 1!

Any help on how to pass this correctly would be appreciated.

Answer 1

Ruby executes on the server side, javascript executes on the client side. The reason this is working now is that the ruby code is executed when the page is loaded.

It is not possible to "pass a javascript variable to ruby" without making an AJAX request to the server.