<!-- Prevent accidentally leaving 'New Post' and 'Edit Post' page. -->  
<script type="text/javascript">  
window.addEventListener('beforeunload',  
function(event) {  
    const url = window.location.href;  
    const body_content = document.getElementById("body_content");  
    // Make sure we're on the NEW POST / EDIT POST page.  
    if (!url.includes('/dashboard/posts/')  
       ||body_content == null) {  
        //console.log("url not match or body_content null");  
        return null;  
    }  

    const target = event.originalTarget.activeElement;  
     
    // If you're submitting or deleting, we allow page exit  
    if (target.getAttribute('type') == 'submit'  
       || target.innerText == 'Delete') {  
        //console.log("is a submission or deletion");  
        return null;  
    }  

    //console.log("confirm exit");  
    // it's a new/edit post (or page), so let's confirm you want to leave  
    const msg = "Are you sure you want to leave this page?";  
    // the .returnValue approach "is consistent across modern versions of Firefox, Safari, and Chrome." according to mdn, but I leave the return msg as a fallback for niche browsers in case they do it wrong.  
    (event || window.event).returnValue = msg;  
    return msg;  
}  
);  

</script>