Unable to To Create Custom Condition

Hi,

I am trying to create custom condition when there is url in custom attribute.

However it is always showing the condition.

I am not sure where has gone wrong.

This is my code:

function filterEventOutputCondition($replacement, $condition, $match, $EM_Event){
    if (is_object($EM_Event)) {
        switch ($condition) {
            // #_ATT{buy_link}
            case 'has_buy_link':
                if (is_array($EM_Event->event_attributes) && !empty($EM_Event->event_attributes['buy_link']))
                    $replacement = preg_replace('/\{\/?has_buy_link\}/', '', $match);
                else
                    $replacement = '';
                break;
        }
    }
    return $replacement;
}
add_filter('em_event_output_condition', 'filterEventOutputCondition', 10, 4);

I can use this custom attribute just fine #_ATT{buy_link} but I want to hide it when the field empty.

Here is the code that I intend to use at the format page:
{has_buy_link}<p><a hre="#_ATT{buy_link}" target="_blank">Buy</a></p>{/has_buy_link}

Suggestion?

https://www.ads-software.com/plugins/events-manager/