fix: return early if $data is empty

boot.php

@@ -9,4 +9,9 @@
     \rex_extension::register('YFORM_DATA_LIST_LINKS', 'YFormExport\ExtensionPoints::YFORM_DATA_LIST_LINKS');
 
     new Export();
+
+    /**
+     * register EP, attach messages.
+     */
+    \rex_extension::register('YFORM_MANAGER_DATA_PAGE_HEADER', 'YFormExport\ExtensionPoints::YFORM_MANAGER_DATA_PAGE_HEADER');
 }

lang/de_de.lang

@@ -0,0 +1 @@
+yform_export_data_empty = Es wurde keine Daten zum Exportieren gefunden.

lang/en_gb.lang

@@ -0,0 +1 @@
+yform_export_data_empty = No data found to export.

lib/Export.php

@@ -143,7 +143,10 @@ private function setRelations(): void
 
         if ($tableRelations) {
             foreach ($tableRelations as $column => $field) {
-                $relations[$column] = rex_yform_value_be_manager_relation::getListValues($field->getElement('table'), $field->getElement('field'));
+                $relations[$column] = rex_yform_value_be_manager_relation::getListValues(
+                    $field->getElement('table'),
+                    $field->getElement('field'),
+                );
             }
 
             $i = 2;
@@ -190,6 +193,12 @@ private function exportTableSet(): void
         /** set column types to format cells */
         $this->setColumnTypes();
 
+        /** exit early if $data is empty */
+        if (empty($data)) {
+            rex::setProperty('yform_export_data_empty', true);
+            return;
+        }
+
         /** set header labels */
         $this->setHeader($data[0]);
 
@@ -281,7 +290,11 @@ private function exportTableSet(): void
 
         $writer = new Xlsx($this->spreadsheet);
         header('Content-Type: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet');
-        header('Content-Disposition: attachment; filename="' . urlencode(time() . '_' . $this->table->getTableName() . '.xlsx') . '"');
+        header(
+            'Content-Disposition: attachment; filename="' . urlencode(
+                time() . '_' . $this->table->getTableName() . '.xlsx',
+            ) . '"',
+        );
         $writer->save('php://output');
         exit;
     }

lib/ExtensionPoints.php

@@ -2,10 +2,12 @@
 
 namespace YFormExport;
 
+use rex;
 use rex_exception;
 use rex_extension_point;
 use rex_i18n;
 use rex_url;
+use rex_view;
 use rex_yform_manager_table;
 
 class ExtensionPoints
@@ -23,6 +25,7 @@ public static function YFORM_DATA_LIST_LINKS(rex_extension_point $ep): void // p
         $linkParams = [
             'func' => 'yform_table_export',
             'table' => $table->getTableName(),
+            'table_name' => $table->getTableName(),
         ];
 
         $item = [];
@@ -36,4 +39,23 @@ public static function YFORM_DATA_LIST_LINKS(rex_extension_point $ep): void // p
         $linkSets['table_links'][] = $item;
         $ep->setSubject($linkSets);
     }
+
+    /**
+     * add messages.
+     * @throws rex_exception
+     */
+    public static function YFORM_MANAGER_DATA_PAGE_HEADER(rex_extension_point $ep): void // phpcs:ignore
+    {
+        $tableHeader = $ep->getSubject();
+        $message = '';
+
+        /**
+         * show message if no data is available.
+         */
+        if (rex::hasProperty('yform_export_data_empty')) {
+            $message = rex_view::error(rex_i18n::msg('yform_export_data_empty'));
+        }
+
+        $ep->setSubject($tableHeader . $message);
+    }
 }

package.yml

@@ -1,14 +1,15 @@
 package: yform_export
-version: '0.0.1'
+version: '0.0.11'
 author: eaCe
 supportpage: https://github.com/eaCe/yform_export
 
 requires:
     packages:
         yform: '^4.0.0'
-    redaxo: '^5.10.0'
+    redaxo: '^5.12.0'
     php:
-        version: '>=7.4'
+        version: '>=8.0'
+
 installer_ignore:
     - node_modules
     - .git