Question

I have a JavaScript variable:

var selectValUser = $('.select_user :selected').val();

I need to use this variable in erb code on the same page, i.e

<%= get_free_hours_for_user(selectValUser) %>

How can I do it?

Answer 1

You cannot do it because javascript run on client side while the code in ERB file runs at server side, you can send the value using ajax request,
Plus here is an awsome rails cast

Here is an example to send message from javascript to controller; When user click on apply we have an action ‘set_id’ in controller, it get the power, do the validations etc, the show the message in ‘id_message’ div in views.

  $('#apply').live('click', function(event, data, status, xhr) {
    event.preventDefault();
    return $.ajax({
      url: '/users/registrations/set_id',
      type: 'GET',
      data: {
        code: $('#user_id').val()
      },
      success: function(data, event, status, xhr) {
        $('#id_message').html(response);
        return $("#id_message").show();
      },
      error: function(event, data, status, xhr) {
        $('#id_message').html(response);
        return $("#id_message").show();
      }
    });
  });

Hope it would answer your question