https://trinityloft.com/includes/knock-availability.js

1// Capture availability clicks before the legacy menu's onclick handler.
2(function () {
3  var waitingForKnock = false;
4  document.addEventListener('click', function (event) {
5    var link = event.target;
6    while (link && link !== document) {
7      if (link.getAttribute && link.getAttribute('data-knock-availability') !== null) break;
8      link = link.parentNode;
9    }
10    if (!link || link === document) return;
11    event.preventDefault();
12    var doorway = window.knockDoorway;
13    if (doorway && typeof doorway.openAvailabilities === 'function') {
14      doorway.openAvailabilities();
15    } else if (doorway && typeof doorway.addOnLoadHandler === 'function' && !waitingForKnock) {
16      waitingForKnock = true;
17      doorway.addOnLoadHandler(function () {
18        waitingForKnock = false;
19        if (typeof doorway.openAvailabilities === 'function') doorway.openAvailabilities();
20      });
21    }
22  }, true);
23}());