Auto refresh <div> without reload entire page - ruby-on-rails

Question

I'm trying to update the content of "mydiv" without refreshing the entire index page.
#mydata is given by mycontroller. I need to recalculate it every n seconds and pass it to "mydiv"
With "link_to" it works!
index.html.erb
<%=
link_to('refresh', '/mycontroller/index', :remote => true)
%>
<div id="mydiv">
<%=
#mydata
%>
</div>
index.js.erb
$('#mydiv').html('<%= escape_javascript(#mydata) %>')
Now I need to refresh the content of "mydiv" automatically every n seconds (so without click on the link). I have tried solutions from:
First Link
Second Link
but no luck.
In my application.js I have writed this:
function executeQuery() {
$.ajax({
//url: '/index',
success: function(data) {
$('#mydiv').html(data)
}
});
setTimeout(executeQuery, 500);
}
$(document).ready(function() {
setTimeout(executeQuery, 500);
});
For who is facing my same problem, I solved it by replacing
$('#mydiv').html(data)
with
$('#mydiv').load('/mycontroller/index #mydiv')

Answer 1

Use setInterval() instead of using setTimeout().
Ref: https://www.w3schools.com/jsref/met_win_setinterval.asp
function executeQuery() {
$.ajax({
type: 'GET',
url: 'example.com/url/', // Provide your response URL here.
success: function(data) {
$('#mydiv').html(data);
}
});
}
setInterval(executeQuery(), (n * 1000)); // Replace 'n' with how many seconds you want.
This code will run the executeQuery() method in every 'n' seconds interval. So that your requirement is accomplished.

Answer 2

Set layout to false in the action and just pass on the relevent content, not the entire page
def action1
<your code here>
end
def action2
<your code here>
render :layout => false
end
Your view for action2 should have content pertaining only to #mydiv.
A better solution would be to use a single action and change render options based on type of request. (Ajax or non ajax)