Disable appointment selection for holidays

src/calendar.js

@@ -1,7 +1,7 @@
  $(document).ready(function() {
     var queryString = window.location.search;
     var calendar = $('#calendar').fullCalendar({
-
+        selectable: true,
         editable: false,
 
         header: {
@@ -15,15 +15,31 @@
             "holiday_feed.php" + queryString
         ],
 
-        selectable: true,
-        selectHelper: true,
-
         select: function(start, end) {
             $("#dialog-form").dialog({ modal: true, width:450});
             var date = $.fullCalendar.formatDate(start, 'YYYY-MM-DD');
             $("#fecha").val(date);
         },
 
+        selectAllow: function(selectInfo){
+            var holidays = null;
+            $.ajax({
+                url: 'holiday_feed.php',
+                async: false,
+                dataType: 'json',
+                success: function (json) {
+                    holidays = json;
+                }
+            });
+            var date = selectInfo.start._d;
+            var formatted_date = date.toISOString().substr(0, 10);
+            var found = holidays.find(el => el.start === formatted_date);
+            if(found == null){
+                return true;
+            }
+            return false;
+        },
+
         eventClick: function(event) {
             var start = $.fullCalendar.formatDate(event.start, 'HH:mm');
             var end = $.fullCalendar.formatDate(event.end, 'HH:mm');