Pass variable from JavaScript to Ruby session

Question

I have a simple input text field:

<input type="text" id="master_password" size="20" placeholder="Master Password" />
<a class="btn btn-default" id="master_submit" href="#">Submit</a>

And some javascript listening:

$(document).ready(function() {
 $('#master_submit').click(function() {
 alert("sometext");
 });
});

The alert works, obviously. I want to store the text field (#master_password) in session[:master_pass] as I will be using it to decrypt many passwords stored in the database. I'm pretty sure I have to use some AJAX, but not familiar with it at all. What code would I replace the alert with in the js file (or view, or controller, of course) to store the data as a Ruby variable?

• Jordan Running: I have edited your question to say "JavaScript" instead of "Java." Java is a completely different programming language and the names cannot be used interchangeably. As a cleverer person than me once said, "Java is to JavaScript as ham is to hamster."
• Cameron Aziz: Yes, aware. My mistake. Nice quote.

Answer 1

Assuming you're using Rails, you could use javascript to make an AJAX request to the Rails app, and then in Rails, you could set the session value.

In Javascript (jQuery):

var data = "password=" + encodeURIComponent($('#master_password').val());
$.ajax({
 url: '/my_controller/action',
 data: data,
 type: 'post'
})
.done(function(response) {
 // Do something with the response
})
.fail(function(error) {
 // Do something with the error
});

And in Rails, setup a controller with the appropriate route, and in the action:

class MyController < ApplicationController
 ...
 def action # << name whatever you like
 session[:password] = params[:password]
 end
 ...
end