documenting functions javascript
/**
* Toggle visibility of a content tab
* @param {String} selector Selector for the element
* @param {Node} toggle The element that triggered the tab
*/
var toggleVisibility = function (selector, toggle) {
if (!selector) return;
var elem = document.querySelector(selector);
if (!elem) return;
elem.classList.add('active');
if (toggle) {
toggle.classList.add('active');
}
elem.focus()
if (document.activeElement.matches(selector)) return;
elem.setAttribute('tabindex', '-1');
elem.focus();
};