fix: resolve release blockers #97 (scalar JSON-LD 500) and #98 (no edit UI)

#97 — Fatal frontend 500 from scalar custom_schema:
- MokoOGContent::validateJson() now requires a JSON object/array (rejects
  scalars like 42/"x"/true that previously passed and were stored)
- MokoOG render path guards with is_array($decoded) so already-stored
  scalar payloads can no longer crash the public page

#98 — Missing single-tag create/edit admin UI:
- Add Controller/TagController (FormController), View/Tag/HtmlView, tmpl/tag/edit.php
- Link OG title in the list to the editor; add New/Edit toolbar buttons
- Declare tmpl/tag folder in the component manifest
- tag.xml: switch cross-package PLG_CONTENT_* labels to COM_MOKOOG_* keys,
  make content_type/content_id editable+required (enables New), add language field
- Add the new COM_MOKOOG_* strings to en-GB and en-US

Also fixes #77 while here: seo_title/meta_description form maxlength now
match the DB columns (70/200) instead of 255.

source/packages/com_mokoog/forms/tag.xml

@@ -16,13 +16,15 @@
             name="content_type"
             type="text"
             label="COM_MOKOOG_FIELD_CONTENT_TYPE"
-            readonly="true"
+            description="COM_MOKOOG_FIELD_CONTENT_TYPE_DESC"
+            required="true"
         />
         <field
             name="content_id"
             type="number"
             label="COM_MOKOOG_FIELD_CONTENT_ID"
-            readonly="true"
+            description="COM_MOKOOG_FIELD_CONTENT_ID_DESC"
+            required="true"
         />
         <field
             name="og_title"
@@ -77,37 +79,45 @@
             <option value="1">JPUBLISHED</option>
             <option value="0">JUNPUBLISHED</option>
         </field>
+        <field
+            name="language"
+            type="contentlanguage"
+            label="JFIELD_LANGUAGE_LABEL"
+            default="*"
+        >
+            <option value="*">JALL</option>
+        </field>
     </fieldset>
-    <fieldset name="seo" label="SEO Meta Tags">
+    <fieldset name="seo" label="COM_MOKOOG_FIELDSET_SEO">
         <field
             name="seo_title"
             type="text"
-            label="PLG_CONTENT_MOKOOG_FIELD_SEO_TITLE"
-            description="PLG_CONTENT_MOKOOG_FIELD_SEO_TITLE_DESC"
+            label="COM_MOKOOG_FIELD_SEO_TITLE"
+            description="COM_MOKOOG_FIELD_SEO_TITLE_DESC"
             filter="string"
-            maxlength="255"
+            maxlength="70"
         />
         <field
             name="meta_description"
             type="textarea"
-            label="PLG_CONTENT_MOKOOG_FIELD_META_DESCRIPTION"
-            description="PLG_CONTENT_MOKOOG_FIELD_META_DESCRIPTION_DESC"
+            label="COM_MOKOOG_FIELD_META_DESCRIPTION"
+            description="COM_MOKOOG_FIELD_META_DESCRIPTION_DESC"
             filter="string"
             rows="3"
-            maxlength="255"
+            maxlength="200"
         />
         <field
             name="robots"
             type="text"
-            label="PLG_CONTENT_MOKOOG_FIELD_ROBOTS"
-            description="PLG_CONTENT_MOKOOG_FIELD_ROBOTS_DESC"
+            label="COM_MOKOOG_FIELD_ROBOTS"
+            description="COM_MOKOOG_FIELD_ROBOTS_DESC"
             filter="string"
         />
         <field
             name="canonical_url"
             type="url"
-            label="PLG_CONTENT_MOKOOG_FIELD_CANONICAL_URL"
-            description="PLG_CONTENT_MOKOOG_FIELD_CANONICAL_URL_DESC"
+            label="COM_MOKOOG_FIELD_CANONICAL_URL"
+            description="COM_MOKOOG_FIELD_CANONICAL_URL_DESC"
             filter="url"
         />
     </fieldset>

source/packages/com_mokoog/language/en-GB/com_mokoog.ini

@@ -66,3 +66,19 @@ COM_MOKOOG_COVERAGE_ARTICLES="%d of %d articles have OG tags"
 COM_MOKOOG_COVERAGE_MISSING_TITLE="%d tags missing custom title"
 COM_MOKOOG_COVERAGE_MISSING_DESC="%d tags missing custom description"
 COM_MOKOOG_COVERAGE_MISSING_IMAGE="%d tags missing custom image"
+
+; Single-tag edit form
+COM_MOKOOG_TAG_NEW="MokoSuiteOpenGraph - New OG Tag"
+COM_MOKOOG_TAG_EDIT="MokoSuiteOpenGraph - Edit OG Tag"
+COM_MOKOOG_TAB_DETAILS="Details"
+COM_MOKOOG_FIELDSET_SEO="SEO Meta Tags"
+COM_MOKOOG_FIELD_CONTENT_TYPE_DESC="The content type this OG tag applies to (e.g. com_content, menu, com_content.category)."
+COM_MOKOOG_FIELD_CONTENT_ID_DESC="The ID of the content item this OG tag applies to."
+COM_MOKOOG_FIELD_SEO_TITLE="SEO Title"
+COM_MOKOOG_FIELD_SEO_TITLE_DESC="Overrides the page <title> tag (max 70 characters)."
+COM_MOKOOG_FIELD_META_DESCRIPTION="Meta Description"
+COM_MOKOOG_FIELD_META_DESCRIPTION_DESC="Overrides the page meta description (max 200 characters)."
+COM_MOKOOG_FIELD_ROBOTS="Robots"
+COM_MOKOOG_FIELD_ROBOTS_DESC="Per-page robots directive, e.g. noindex, nofollow."
+COM_MOKOOG_FIELD_CANONICAL_URL="Canonical URL"
+COM_MOKOOG_FIELD_CANONICAL_URL_DESC="Overrides the canonical URL for this content item (http/https only)."

source/packages/com_mokoog/language/en-US/com_mokoog.ini

@@ -66,3 +66,19 @@ COM_MOKOOG_COVERAGE_ARTICLES="%d of %d articles have OG tags"
 COM_MOKOOG_COVERAGE_MISSING_TITLE="%d tags missing custom title"
 COM_MOKOOG_COVERAGE_MISSING_DESC="%d tags missing custom description"
 COM_MOKOOG_COVERAGE_MISSING_IMAGE="%d tags missing custom image"
+
+; Single-tag edit form
+COM_MOKOOG_TAG_NEW="MokoSuiteOpenGraph - New OG Tag"
+COM_MOKOOG_TAG_EDIT="MokoSuiteOpenGraph - Edit OG Tag"
+COM_MOKOOG_TAB_DETAILS="Details"
+COM_MOKOOG_FIELDSET_SEO="SEO Meta Tags"
+COM_MOKOOG_FIELD_CONTENT_TYPE_DESC="The content type this OG tag applies to (e.g. com_content, menu, com_content.category)."
+COM_MOKOOG_FIELD_CONTENT_ID_DESC="The ID of the content item this OG tag applies to."
+COM_MOKOOG_FIELD_SEO_TITLE="SEO Title"
+COM_MOKOOG_FIELD_SEO_TITLE_DESC="Overrides the page <title> tag (max 70 characters)."
+COM_MOKOOG_FIELD_META_DESCRIPTION="Meta Description"
+COM_MOKOOG_FIELD_META_DESCRIPTION_DESC="Overrides the page meta description (max 200 characters)."
+COM_MOKOOG_FIELD_ROBOTS="Robots"
+COM_MOKOOG_FIELD_ROBOTS_DESC="Per-page robots directive, e.g. noindex, nofollow."
+COM_MOKOOG_FIELD_CANONICAL_URL="Canonical URL"
+COM_MOKOOG_FIELD_CANONICAL_URL_DESC="Overrides the canonical URL for this content item (http/https only)."

source/packages/com_mokoog/mokoog.xml

@@ -50,6 +50,7 @@
             <folder>View</folder>
         </files>
         <files folder="tmpl">
+            <folder>tag</folder>
             <folder>tags</folder>
         </files>
         <files folder="sql">

source/packages/com_mokoog/src/Controller/TagController.php

@@ -0,0 +1,31 @@
+<?php
+
+/**
+ * @package     MokoSuiteOpenGraph
+ * @subpackage  com_mokoog
+ * @author      Moko Consulting <hello@mokoconsulting.tech>
+ * @copyright   Copyright (C) 2026 Moko Consulting. All rights reserved.
+ * @license     GNU General Public License version 3 or later; see LICENSE
+ */
+
+namespace Joomla\Component\MokoOG\Administrator\Controller;
+
+defined('_JEXEC') or die;
+
+use Joomla\CMS\MVC\Controller\FormController;
+
+/**
+ * Controller for a single OG tag record.
+ *
+ * Provides the standard add/edit/save/apply/cancel tasks via FormController,
+ * backed by the existing TagModel (AdminModel) and TagTable.
+ */
+class TagController extends FormController
+{
+    /**
+     * The list view to redirect to after save/cancel.
+     *
+     * @var string
+     */
+    protected $view_list = 'tags';
+}

source/packages/com_mokoog/src/View/Tag/HtmlView.php

@@ -0,0 +1,76 @@
+<?php
+
+/**
+ * @package     MokoSuiteOpenGraph
+ * @subpackage  com_mokoog
+ * @author      Moko Consulting <hello@mokoconsulting.tech>
+ * @copyright   Copyright (C) 2026 Moko Consulting. All rights reserved.
+ * @license     GNU General Public License version 3 or later; see LICENSE
+ */
+
+namespace Joomla\Component\MokoOG\Administrator\View\Tag;
+
+defined('_JEXEC') or die;
+
+use Joomla\CMS\Factory;
+use Joomla\CMS\Language\Text;
+use Joomla\CMS\MVC\View\HtmlView as BaseHtmlView;
+use Joomla\CMS\Toolbar\ToolbarHelper;
+
+/**
+ * Edit view for a single OG tag record.
+ */
+class HtmlView extends BaseHtmlView
+{
+    /**
+     * The edit form.
+     *
+     * @var \Joomla\CMS\Form\Form
+     */
+    protected $form;
+
+    /**
+     * The item being edited.
+     *
+     * @var object
+     */
+    protected $item;
+
+    /**
+     * Display the view.
+     *
+     * @param   string  $tpl  Template name
+     *
+     * @return  void
+     */
+    public function display($tpl = null): void
+    {
+        $this->form = $this->get('Form');
+        $this->item = $this->get('Item');
+
+        $this->addToolbar();
+
+        parent::display($tpl);
+    }
+
+    /**
+     * Add the edit toolbar.
+     *
+     * @return  void
+     */
+    protected function addToolbar(): void
+    {
+        Factory::getApplication()->getInput()->set('hidemainmenu', true);
+
+        $isNew = empty($this->item->id);
+
+        ToolbarHelper::title(
+            Text::_($isNew ? 'COM_MOKOOG_TAG_NEW' : 'COM_MOKOOG_TAG_EDIT'),
+            'bookmark'
+        );
+
+        ToolbarHelper::apply('tag.apply');
+        ToolbarHelper::save('tag.save');
+        ToolbarHelper::cancel('tag.cancel', $isNew ? 'JTOOLBAR_CANCEL' : 'JTOOLBAR_CLOSE');
+    }
+}

source/packages/com_mokoog/src/View/Tags/HtmlView.php

@@ -81,6 +81,8 @@ class HtmlView extends BaseHtmlView
     protected function addToolbar(): void
     {
         ToolbarHelper::title(Text::_('COM_MOKOOG_TAGS_TITLE'), 'bookmark');
+        ToolbarHelper::addNew('tag.add');
+        ToolbarHelper::editList('tag.edit');
         ToolbarHelper::custom('batch.generate', 'refresh', '', 'COM_MOKOOG_TOOLBAR_BATCH_GENERATE', false);
         ToolbarHelper::custom('importexport.export', 'download', '', 'COM_MOKOOG_TOOLBAR_EXPORT', false);
         ToolbarHelper::deleteList('JGLOBAL_CONFIRM_DELETE', 'tags.delete');

source/packages/com_mokoog/tmpl/tag/edit.php

@@ -0,0 +1,41 @@
+<?php
+
+/**
+ * @package     MokoSuiteOpenGraph
+ * @subpackage  com_mokoog
+ * @author      Moko Consulting <hello@mokoconsulting.tech>
+ * @copyright   Copyright (C) 2026 Moko Consulting. All rights reserved.
+ * @license     GNU General Public License version 3 or later; see LICENSE
+ */
+
+defined('_JEXEC') or die;
+
+use Joomla\CMS\HTML\HTMLHelper;
+use Joomla\CMS\Language\Text;
+use Joomla\CMS\Router\Route;
+
+/** @var \Joomla\Component\MokoOG\Administrator\View\Tag\HtmlView $this */
+
+HTMLHelper::_('behavior.formvalidator');
+?>
+<form action="<?php echo Route::_('index.php?option=com_mokoog&view=tag&layout=edit&id=' . (int) ($this->item->id ?? 0)); ?>"
+      method="post" name="adminForm" id="adminForm" class="form-validate" aria-label="<?php echo $this->escape(Text::_('COM_MOKOOG_TAG_EDIT')); ?>">
+    <div class="row">
+        <div class="col-lg-9">
+            <?php echo HTMLHelper::_('uitab.startTabSet', 'mokoogTab', ['active' => 'details']); ?>
+
+            <?php echo HTMLHelper::_('uitab.addTab', 'mokoogTab', 'details', Text::_('COM_MOKOOG_TAB_DETAILS')); ?>
+                <?php echo $this->form->renderFieldset('details'); ?>
+            <?php echo HTMLHelper::_('uitab.endTab'); ?>
+
+            <?php echo HTMLHelper::_('uitab.addTab', 'mokoogTab', 'seo', Text::_('COM_MOKOOG_FIELDSET_SEO')); ?>
+                <?php echo $this->form->renderFieldset('seo'); ?>
+            <?php echo HTMLHelper::_('uitab.endTab'); ?>
+
+            <?php echo HTMLHelper::_('uitab.endTabSet'); ?>
+        </div>
+    </div>
+
+    <input type="hidden" name="task" value="">
+    <?php echo HTMLHelper::_('form.token'); ?>
+</form>

source/packages/com_mokoog/tmpl/tags/default.php

@@ -85,7 +85,9 @@ $token = Session::getFormToken();
                                         <?php echo (int) $item->content_id; ?>
                                     </td>
                                     <td>
-                                        <?php echo $this->escape($item->og_title ?: '(' . Text::_('COM_MOKOOG_AUTO_GENERATED') . ')'); ?>
+                                        <a href="<?php echo Route::_('index.php?option=com_mokoog&task=tag.edit&id=' . (int) $item->id); ?>" title="<?php echo Text::_('JACTION_EDIT'); ?>">
+                                            <?php echo $this->escape($item->og_title ?: '(' . Text::_('COM_MOKOOG_AUTO_GENERATED') . ')'); ?>
+                                        </a>
                                     </td>
                                     <td>
                                         <?php if ($item->og_image) : ?>

source/packages/plg_content_mokoog/src/Extension/MokoOGContent.php

@@ -322,7 +322,14 @@ final class MokoOGContent extends CMSPlugin implements SubscriberInterface
     {
         $json = trim($json);
 
-        if ($json === '' || json_decode($json) === null) {
+        if ($json === '') {
+            return '';
+        }
+
+        // Only accept JSON objects/arrays. Scalars (42, "x", true) decode to a
+        // non-null value but would crash the frontend renderer when treated as
+        // an array (writing $decoded['@context'] onto a scalar is a fatal error).
+        if (!\is_array(json_decode($json, true))) {
             return '';
         }
 

source/packages/plg_system_mokoog/src/Extension/MokoOG.php

@@ -358,7 +358,9 @@ final class MokoOG extends CMSPlugin implements SubscriberInterface
             if (!empty($customSchema)) {
                 $decoded = json_decode($customSchema, true);
 
-                if ($decoded) {
+                // Guard against scalar/invalid payloads — only arrays/objects are
+                // valid JSON-LD. Writing an array offset onto a scalar is fatal.
+                if (\is_array($decoded) && $decoded !== []) {
                     if (empty($decoded['@context'])) {
                         $decoded['@context'] = 'https://schema.org';
                     }