MDL-84862 AI: Stop provider instance creataion when no provider plugins

Prevents calls to action to create an AI provider instance from
being displayed to users when there are no AI provider plugins
installed in the instance.

Co-Authored-By: Yusuf Wibisono <[email protected]>

public/admin/classes/admin/admin_setting_notification.php

@@ -0,0 +1,74 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+namespace core_admin\admin;
+
+use admin_setting;
+
+/**
+ * Render a notification as part of other admin settings.
+ *
+ * @package    core_admin
+ * @subpackage admin
+ * @copyright  2025 Matt Porritt <[email protected]>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class admin_setting_notification extends admin_setting {
+    /**
+     * Constructor.
+     *
+     * @param string $name The name of the setting.
+     * @param string $notification The notification to display.
+     * @param string $type The type of notification.
+     * @param bool $cancelable Whether the notification can be canceled.
+     */
+    public function __construct(
+        string $name,
+        /** @var string The notification to display. */
+        protected string $notification,
+        /** @var string The type of notification. */
+        protected string $type = 'info',
+        /** @var bool Whether the notification can be canceled. */
+        protected bool $cancelable = false
+    ) {
+        $this->nosave = true;
+
+        parent::__construct($name, '', '', '');
+    }
+
+    #[\Override]
+    public function get_setting(): bool {
+        return true;
+    }
+
+    #[\Override]
+    public function get_defaultsetting(): bool {
+        return true;
+    }
+
+    #[\Override]
+    public function write_setting($data): string {
+        // Do not write any setting.
+        return '';
+    }
+
+    #[\Override]
+    public function output_html($data, $query = ''): string {
+        global $OUTPUT;
+
+        return $OUTPUT->notification($this->notification, $this->type, $this->cancelable);
+    }
+}

public/admin/settings/ai.php

@@ -32,19 +32,29 @@ if ($hassiteconfig) {
     $providers->add(new admin_setting_heading('availableproviders',
         get_string('availableproviders', 'core_ai'),
         get_string('availableproviders_desc', 'core_ai')));
-    // Add call to action to add a new provider.
-    $providers->add(new \core_admin\admin\admin_setting_template_render(
-        name: 'addnewprovider',
-        templatename: 'core_ai/admin_add_provider',
-        context: ['addnewproviderurl' => new moodle_url('/ai/configure.php')]
-    ));
 
-    $providers->add(new \core_ai\admin\admin_setting_provider_manager(
+    if (!empty(core_plugin_manager::instance()->get_plugins_of_type("aiprovider"))) {
+        // Add call to action to add a new provider.
+        $providers->add(new \core_admin\admin\admin_setting_template_render(
+            name: 'addnewprovider',
+            templatename: 'core_ai/admin_add_provider',
+            context: ['addnewproviderurl' => new moodle_url('/ai/configure.php')]
+        ));
+
+        $providers->add(new \core_ai\admin\admin_setting_provider_manager(
             'aiprovider',
             \core_ai\table\aiprovider_management_table::class,
             'manageaiproviders',
             new lang_string('manageaiproviders', 'core_ai'),
-    ));
+        ));
+    } else {
+        $providers->add(new \core_admin\admin\admin_setting_notification(
+            name:'noproviderplugins',
+            notification: get_string('noproviderplugins', 'core_ai'),
+            type: 'danger'
+        ));
+    }
+
     $ADMIN->add('ai', $providers);
 
     // Add settings page for AI placement settings.

public/ai/configure.php

@@ -72,6 +72,12 @@ $PAGE->set_pagelayout('admin');
 $PAGE->set_title($title);
 $PAGE->set_heading($title);
 
+// Explode if there are no provider plugins installed.
+$plugins = core_plugin_manager::instance()->get_plugins_of_type('aiprovider');
+if (empty($plugins)) {
+    throw new moodle_exception('noproviderplugins', 'core_ai');
+}
+
 // Provider instance form processing.
 $mform = new \core_ai\form\ai_provider_form(customdata: $data);
 if ($mform->is_cancelled()) {

public/lang/en/ai.php

@@ -123,6 +123,7 @@ $string['globalratelimit'] = 'Maximum number of site-wide requests';
 $string['globalratelimit_help'] = 'The number of site-wide requests allowed per hour.';
 $string['manageaiplacements'] = 'Manage AI placements';
 $string['manageaiproviders'] = 'Manage AI providers';
+$string['noproviderplugins'] = 'There are no provider plugins installed. Install a provider plugin to enable provider instance creation.';
 $string['noproviders'] = 'This action is unavailable. No <a href="{$a}">AI providers</a> are configured for this action.';
 $string['off'] = 'Off';
 $string['on'] = 'On';