Navigational History Problem: JavaScript Ceases to Execute After Using Firefox Back Button

Firefox users may encounter an issue where JavaScript scripts fail to run upon returning to a previously visited page via the back button. This problem does not occur in other browsers like Chrome and Internet Explorer.

Cause and Solution:

This behavior is caused by the browser caching JavaScript resources. To resolve this issue and ensure scripts execute on subsequent page visits, Firefox users should set an empty function to be called on window.onunload event.

Implementation:

<pre>
<script type="text/javascript">
window.onload = function() { alert('window.onload alert'); };
window.onunload = function(){}; // Empty function to resolve issue
alert('inline alert');
</script>
</pre>

Explanation:

The window.onunload event is triggered when a page is unloaded or navigated away from. By setting an empty function to this event, Firefox will perform a cleanup action, causing JavaScript resources to be re-loaded when the page is visited again.

Source:

• http://www.firefoxanswer.com/firefox/672-firefoxanswer.html (Archived Version)