ISTWCMS-4704: fixing error of null array and updating tags in footer to use proper format

src/Service/UWService.php

@@ -480,6 +480,11 @@ class UWService implements UWServiceInterface {
    */
   public function uwGetHeaderData(Node $node): array {
 
+    // Array to hold the header data, need to set to
+    // null in case there are no header data to be
+    // returned.
+    $header_data = [];
+
     // Get the header data, depending on the content type.
     switch ($node->getType()) {
 
@@ -525,7 +530,7 @@ class UWService implements UWServiceInterface {
     switch ($node->getType()) {
       case 'uw_ct_blog';
         $footer_data = [
-          'tags' => $this->uwGetTerms($node->get('field_uw_blog_tags')->getValue(), 'tags'),
+          'tags' => [$this->uwGetTerms($node->get('field_uw_blog_tags')->getValue(), 'tags')],
         ];
         break;
     }