To check the condition whether the module is installed or uninstalled

To check the condition whether the module is installed or uninstalled to display particular block in tpl file

{if Module::isInstalled("productcomments")}
<div>This block is to be displayed only when module is installed</div>
{/if}

I got PHP notices in Stats tab

Notice: Use of undefined constant _PS_CREATION_DATE_ - assumed '_PS_CREATION_DATE_' in /www/modules/statsforecast/statsforecast.php on line 85


Go to line no:85

Instead of

$from = max(strtotime(_PS_CREATION_DATE_.' 00:00:00'), strtotime($employee->stats_date_from.' 00:00:00')); 

Replace this below code

$from = max(strtotime('_PS_CREATION_DATE_'.' 00:00:00'), strtotime($employee->stats_date_from.' 00:00:00'));