Issue #2946641: Support date_recur field type.

I will comment on the issue with a description of the changes.

src/CalendarProperty/CalendarPropertyProcessor.php

@@ -128,10 +128,11 @@ class CalendarPropertyProcessor {
    */
   private function processDateList(ContentEntityInterface $contentEntity) {
 
-    $calendarProperties = [];
+    $datesList = [];
     if (!empty($this->dateFieldReference)) {
       foreach ($contentEntity->get($this->dateFieldReference)
-                             ->getValue() as $dateVal) {
+                             ->getValue() as $key => $dateVal) {
+        // Add start date.
         $date = NULL;
         if (isset($dateVal['value'])) {
           $date = $dateVal['value'];
@@ -142,11 +143,31 @@ class CalendarPropertyProcessor {
         }
 
         if ($date) {
-          $calendarProperties[] = date("Y-m-d\TH:i:s", strtotime($date));
+          $datesList[$key]['startdate'] = date("Y-m-d\TH:i:s", strtotime($date));
+        }
+
+        // Add end date.
+        if (isset($dateVal['end_value'])) {
+          $date = $dateVal['end_value'];
+
+          // TODO: Remove the check for DrupalDateTime,should be a string-ed date.
+          if ($date instanceof DrupalDateTime) {
+            $date = $dateVal['end_value']->render();
+          }
+
+          if ($date) {
+            $datesList[$key]['enddate'] = date("Y-m-d\TH:i:s", strtotime($date));
+          }
+        }
+
+        // Add RRULE.
+        // This will only be set if the field is a date_recur field.
+        if (isset($dateVal['rrule'])) {
+          $datesList[$key]['rrule'] = $dateVal['rrule'];
         }
       }
     }
-    return $calendarProperties;
+    return $datesList;
   }
 
   /**