Opengraph/custom field

libraries/src/Opengraph/MappableFieldInterface.php

@@ -0,0 +1,32 @@
+<?php
+
+/**
+ * Joomla! Content Management System
+ *
+ * @copyright  (C) 2025 Open Source Matters, Inc. <https://www.joomla.org>
+ * @license    GNU General Public License version 2 or later; see LICENSE.txt
+ */
+
+namespace Joomla\CMS\Opengraph;
+
+// phpcs:disable PSR1.Files.SideEffects
+\defined('_JEXEC') or die;
+// phpcs:enable PSR1.Files.SideEffects
+
+
+/**
+ * Interface for fields that can be mapped to OpenGraph groups.
+ *
+ * @since  __DEPLOY_VERSION__
+ */
+interface MappableFieldInterface
+{
+    /**
+     * Returns the OpenGraph group this field should be listed under.
+     *
+     * @return  OpengraphGroup  One of the enum cases defined in {@see OpengraphGroup}.
+     *
+     * @since   __DEPLOY_VERSION__
+     */
+    public static function getOpengraphGroup(): OpengraphGroup;
+}

libraries/src/Opengraph/OpengraphGroup.php

@@ -0,0 +1,36 @@
+<?php
+
+/**
+ * Joomla! Content Management System
+ *
+ * @copyright  (C) 2025 Open Source Matters, Inc. <https://www.joomla.org>
+ * @license    GNU General Public License version 2 or later; see LICENSE.txt
+ */
+
+namespace Joomla\CMS\Opengraph;
+
+// phpcs:disable PSR1.Files.SideEffects
+\defined('_JEXEC') or die;
+// phpcs:enable PSR1.Files.SideEffects
+
+/**
+ * Enumerates the logical OpenGraph groups that a custom field-type can
+ * register itself under.
+ *
+ * Third-party field-type plugins should return one of these cases from
+ * {@see MappableFieldInterface::getOpengraphGroup()} so the System – OpenGraph
+ * plugin knows how to categorise the field inside its mapping drop-down.
+ *
+ * @since  __DEPLOY_VERSION__
+ */
+enum OpengraphGroup: string
+{
+    /** Standard textual content (e.g. single-line, multi-line). */
+    case TEXT       = 'text-fields';
+
+    /** Image or media file (intro/full images, custom media fields, …). */
+    case IMAGE      = 'image-fields';
+
+    /** Alternate-text associated with an image (accessibility / SEO). */
+    case IMAGE_ALT  = 'image-alt-fields';
+}

plugins/system/opengraph/src/Extension/opengraph.php

@@ -25,6 +25,7 @@
 use Joomla\CMS\Uri\Uri;
 use Joomla\Component\Categories\Administrator\Model\CategoryModel;
 use Joomla\Component\Content\Administrator\Model\ArticleModel;
+use Joomla\Component\Fields\Administrator\Helper\FieldsHelper;
 use Joomla\Event\SubscriberInterface;
 use Joomla\Registry\Registry;
 
@@ -425,8 +426,10 @@ private function getMultipleArticleMenuParams(string $option, string $view, ?int
                     return $active->getParams();
                 }
             } elseif ($view === 'featured') {
+                // For featured view (no category ID)
                 return $active->getParams();
             } else {
+                // For other multi-article views, just return menu params
                 return $active->getParams();
             }
         }
@@ -511,6 +514,23 @@ private function getOgTagsFromCategoryMappings(Registry $categoryParams, object
      */
     private function getFieldValue(object $article, string $fieldName, array $articleImages): string
     {
+
+        // Check if it's a custom field
+        if (strpos($fieldName, 'field.') === 0) {
+            $customFieldName = substr($fieldName, 6);
+            // Load custom fields for the article
+            $customFields = FieldsHelper::getFields('com_content.article', $article, true);
+
+            foreach ($customFields as $field) {
+                if ($field->name == $customFieldName) {
+                    return $field->value ?? '';
+                }
+            }
+
+            return '';
+        }
+
+        // Handle standard article fields
         $value = '';
 
         switch ($fieldName) {

plugins/system/opengraph/src/Field/OpengraphField.php

@@ -10,10 +10,15 @@
 namespace Joomla\Plugin\System\Opengraph\Field;
 
 use Joomla\CMS\Factory;
+use Joomla\CMS\Fields\FieldsServiceInterface;
 use Joomla\CMS\Form\Field\GroupedlistField;
 use Joomla\CMS\HTML\HTMLHelper;
 use Joomla\CMS\Language\Text;
+use Joomla\CMS\Opengraph\MappableFieldInterface;
+use Joomla\CMS\Opengraph\OpengraphGroup;
 use Joomla\CMS\Opengraph\OpengraphServiceInterface;
+use Joomla\CMS\Plugin\PluginHelper;
+use Joomla\Component\Fields\Administrator\Helper\FieldsHelper;
 
 // phpcs:disable PSR1.Files.SideEffects
 \defined('_JEXEC') or die;
@@ -97,6 +102,81 @@ protected function getGroups()
         }
 
 
+
+        if (!$cmp instanceof FieldsServiceInterface) {
+            return $groups;
+        }
+
+        // Allowed field types for each OpenGraph group
+        $allowedFieldTypes = [
+            OpengraphGroup::TEXT->value      => ['text', 'textarea'],
+            OpengraphGroup::IMAGE->value     => ['media', 'imagelist'],
+            OpengraphGroup::IMAGE_ALT->value => ['text'],
+        ];
+
+        $nativeTypes = $allowedFieldTypes[$fieldType] ?? [];
+
+
+
+        $catId = (int) $this->form->getValue('id');        // editing existing cat
+        if (!$catId) {
+            // Creating a new category: use the chosen parent so assignments still work
+            $catId = (int) $this->form->getValue('parent_id');
+        }
+
+        // Dummy item with catid so FieldsService filters by assignment
+        $scopeItem = $catId ? (object) ['catid' => $catId] : null;
+
+        $customFields  = FieldsHelper::getFields('com_content.article', $scopeItem);
+        $customOptions = [];
+
+        foreach ($customFields as $field) {
+            $accept = \in_array($field->type, $nativeTypes, true);
+
+
+            // If not native-allowed, see if the field’s plugin implements our interface
+            if (!$accept) {
+                // Ensure the specific fields plugin is loaded
+                PluginHelper::importPlugin('fields', $field->type);
+
+                $ucType = ucfirst((string) $field->type);
+
+                // Candidate class names in priority order (modern first, then legacy)
+                $candidates = [
+                    "Joomla\\Plugin\\Fields\\{$ucType}\\Extension\\{$ucType}", // J4/5 namespaced
+                    "Joomla\\Plugin\\Fields\\{$ucType}\\Field\\{$ucType}Field", // some third-party patterns
+                    "PlgFields{$ucType}",                                      // legacy non-namespaced
+                ];
+
+                $implements = false;
+
+                foreach ($candidates as $fqcn) {
+                    if (class_exists($fqcn) && is_subclass_of($fqcn, MappableFieldInterface::class)) {
+                        $implements = ($fqcn::getOpengraphGroup()->value === $fieldType);
+                        if ($implements) {
+                            $accept = true;
+                            break;
+                        }
+                    }
+                }
+            }
+
+
+            if (!$accept) {
+                continue;
+            }
+
+
+
+            $label           = $field->title . ' (' . $field->name . ')';
+            $customOptions[] = HTMLHelper::_('select.option', 'field.' . $field->name, $label);
+        }
+
+        if (!empty($customOptions)) {
+            $groups['Custom Fields'] = $customOptions;
+        }
+
+
         return $groups;
     }
 }