Customize FullCalendar Event Display

override.site-fullcalendar-default.min.js

(function (document, Joomla) {
    document.addEventListener('DOMContentLoaded', function () {
        var calendarEl = document.getElementById('eb_full_calendar');
        var calendarOptions = Joomla.getOptions('calendarOptions');

        calendarOptions['eventDidMount'] = function (arg) {
            if (arg.event.extendedProps.tooltip) {
                var element = jQuery(arg.el);
                element.tooltip({
                    title: arg.event.extendedProps.tooltip,
                    trigger: 'hover',
                    placement: 'top',
                    container: 'body',
                    html: true,
                    sanitize: false
                });
            }

            // Location
            if (arg.event.extendedProps.location_name) {
                var eventContainerEl = arg.el.querySelector('.fc-event-title');

                eventContainerEl.insertAdjacentHTML('beforeend', '<br><span class="fc-event-title eb-fullcalendar-location-name"> ' + arg.event.extendedProps.location_name + '</span>');
            }

            // Thumb
            if (arg.event.extendedProps.thumb) {
                var eventContainerEl = arg.el.querySelector('.fc-event-title-container');

                eventContainerEl.insertAdjacentHTML('afterend ', '<div class="eb-fullcalendar-event-thumb"><img src="' + arg.event.extendedProps.thumb + '" /></div>');
            }
        }

        var calendar = new FullCalendar.Calendar(calendarEl, calendarOptions);
        calendar.render();
    });
})(document, Joomla);