Clear Browser Cache Every Nth Day(s) in PHP

This code is useful when you are making a lot of changes to your styles and js scripts and you want your visitors / users to see the updated version page and not the old cached version.

The Process

Create a cookie variable where we will be storing the current time when user visits the website
Subtract current time to old time then get the result in days
Check if the result is greater or equal to the provided nth day(s) $no_of_days
If greater, execute our AJAX cache cleaner script with the help of location.reload(true) then set the cookie variable to the current time. Setting the parameter to true will prevent the browser from fetching the cached version of the page.

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$ajax_cache_cleaner = '
<script type = "text/javascript">
$.ajax({
url: window.location.href,
headers: {
"Pragma": "no-cache",
"Expires": -1,
"Cache-Control": "no-cache"
}
}).done(function () {
window.location.reload(true);
});
</script>';

if( isset( $_COOKIE['clear_browser_cache'] ) ) {
$old_time = $_COOKIE['clear_browser_cache'];
$current_time = time();
$secs = $current_time - $old_time; // seconds between the two times
$days = $secs / 86400;
if( $days >= $no_of_days ) {
setcookie('clear_browser_cache', time(), time() + 86400); // 86400 = 1 day
echo $ajax_cache_cleaner;

}
} else {
setcookie('clear_browser_cache', time(), time() + ( $no_of_days * 86400 ) ); // 86400 = 1 day
echo $ajax_cache_cleaner;
}

Function:

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/*
* Clears the browser cache everyday nth days.
*/
function clear_browser_cache( $no_of_days ) {

$ajax_cache_cleaner = '
<script type = "text/javascript">
$.ajax({
url: window.location.href,
headers: {
"Pragma": "no-cache",
"Expires": -1,
"Cache-Control": "no-cache"
}
}).done(function () {
window.location.reload(true);
});
</script>';

if( isset( $_COOKIE['clear_browser_cache'] ) ) {
$old_time = $_COOKIE['clear_browser_cache'];
$current_time = time();
$secs = $current_time - $old_time; // seconds between the two times
$days = $secs / 86400;
if( $days >= $no_of_days ) {
setcookie('clear_browser_cache', time(), time() + 86400); // 86400 = 1 day
echo $ajax_cache_cleaner;

}
} else {
setcookie('clear_browser_cache', time(), time() + ( $no_of_days * 86400 ) ); // 86400 = 1 day
echo $ajax_cache_cleaner;
}

}

Parameter equals the number of days before executing the cache cleaner script.

Note:

Make sure jQuery is loaded first before using the above function.
Run the function on the Head part of your HTML document.

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