Ideas on simple 'Hello World' Rails-Ajax Example?

Learning/re-learning ajax using rails. I think rails-ajax has changed a lot in last few years so have not found a very simple 'Hello World' type ajax example (w/o resources, w/o records).

This is an attempt (below) at a simple rails ajax example based on references 开发者_Go百科I could find. It works -- however, it seems a bit cumbersome (ie one-to-one .js file to ajax request action). Does anyone have thoughts on an improved (more elegant) rails ajax 'Hello World'?

---------------------
View - 'edit.html.erb' 


 <div id="div_msg">
 <%= link_to "Wow",
  {:controller=>"rectangle_set_model" , :action=>'ajax_msg' , :id=>'1'},
  :remote => true,
  :class => 'link1',
  :update => "div_hello",
  :id => 'link1'
 %>
 </div>

 <div id="div_hello">
 </div>

--------------------- 
Controller - 'rectangle_set_model_controller.rb' 

 def ajax_msg
  @msg1 = "Buenos Dias!"
  respond_to do
   |format|
   format.html
   format.js
   format.xml
  end
 end


--------------------- 
Javascript (corresponding to ajax_msg format.js in controller)
- 'ajax_msg.js' 

$('#div_hello').html("<%= controller.msg1 %>");

--------------------- 

Why do you have to render a JS view ?

Just use UJS and a standard Ajax call. You Rails action can render JSON :

format.js { render :json => { :text => "Hello the world" } }

// application.js
// jQuery
// in $(document).ready(function()...) or $("#my_button").click(function()...)
//
$.ajax({
  url: "/home/hello",
  success: function(response) {
    $("#div_hello").html(response.text);
  }
});

Thanks guys

Samuel - not quite working for some reason

Whenever I enable this line

format.js {render :json => { :text => "Hello the world" }}

I then get error in browser (on action link)

browser popup error --------> Expected ';'

is