Is there a cross-browser onload event when clicking the back button?

Guys, I found that JQuery has only one effect: the page is reloaded when the back button is pressed. This has nothing to do with “ready“.

How does this work? Well, JQuery adds an onunload event listener.

// http://code.jquery.com/jquery-latest.js
jQuery(window).bind("unload", function() { // ...

By default, it does nothing. But somehow this seems to trigger a reload in Safari, Opera and Mozilla — no matter what the event handler contains.

[edit(Nickolay): here’s why it works that way: webkit.org, developer.mozilla.org. Please read those articles (or my summary in a separate answer below) and consider whether you really need to do this and make your page load slower for your users.]

Can’t believe it? Try this:

<body onunload=""><!-- This does the trick -->
<script type="text/javascript">
    alert('first load / reload');
    window.onload = function(){alert('onload')};
</script>
<a href="http://stackoverflow.com">click me, then press the back button</a>
</body>

You will see similar results when using JQuery.

You may want to compare to this one without onunload

<body><!-- Will not reload on back button -->
<script type="text/javascript">
    alert('first load / reload');
    window.onload = function(){alert('onload')};
</script>
<a href="http://stackoverflow.com">click me, then press the back button</a>
</body>

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