upon entering/leaving the page append a string in the url. Is this possible?

Question

Is there a way to append a string in the url upon leaving/entering?

Say the default url is www.foo.com

Then upon entering/leaving, it becomes www.foo.com?param=1 without clicking to something?

Just using javascript.

Any help would be much appreciated. Thanks!

Answer 1

Here is one possible method to do that. This is using jQuery, and only adds the parameter on page entry (on page leave, it's kind of pointless; also, that would trigger on addition for the first case as well) -

<script src="http://code.jquery.com/jquery-1.11.1.min.js"></script>
<script>
$( window ).load(function() {
        if (! window.location.href.contains("param=0")) {
                window.location.href = window.location.href+"?param=0";
        }
});
</script>

Answer 2

The easiest ways to do this would be to change document.location.search (which targets parameters) like this:

    if (document.location.search != ("?param=1")) {
        document.location.search = "?param=1";
    }

note that this essentially triggers a page reload though.