Question

I am writing a script where it checks for an updated version from an external server. I use this code in the config.php file to check for latest version.

$data = get_theme_data('http://externalhost.com/style.css');
$latest_version = $data['Version'];
define('LATEST_VERSION', $latest_version);

This is fine and I can fetch the latest version (get_theme_data is WordPress function) but the problem is that it will be executed on every single load which I do not want. I also do not want to only check when a form is submitted for example. Alternatively I was looking into some sort of method to cache the result or maybe check the version every set amount of hours? Is such thing possible and how?

Answer 1

Here, gonna make it easy for you. Store the time you last checked for the update in a file.

function checkForUpdate() {
    $file = file_get_contents('./check.cfg', true);
    if ($file === "") {
        $fp = fopen('./check.cfg', 'w+');
        fwrite($fp, time() + 86400);
        fclose($fp);
    }
    if ((int)$file > time()) {
        echo "Do not updatE";
    } else {
        echo "Update";
        $fp = fopen('./check.cfg', 'w+');
        fwrite($fp, time() + 86400);
        fclose($fp);
    }
}

You can obviously make this much more secure/efficient if you want to.

Edit: This function will check for update once every day.