MDL-69825 admin: externalpage class using a callback for access check.

Co-Authored-By: Marina Glancy <[email protected]>

admin/classes/local/externalpage/accesscallback.php

@@ -0,0 +1,71 @@
+<?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/>.
+
+/**
+ * External admin page class that allows a callback to be provided to determine whether page can be accessed
+ *
+ * @package     core_admin
+ * @copyright   2019 Marina Glancy
+ * @license     http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+namespace core_admin\local\externalpage;
+
+use admin_externalpage;
+
+defined('MOODLE_INTERNAL') || die();
+
+require_once("{$CFG->libdir}/adminlib.php");
+
+/**
+ * Admin externalpage class
+ *
+ * @package     core_admin
+ * @copyright   2019 Marina Glancy
+ * @license     http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class accesscallback extends admin_externalpage {
+
+    /** @var callable $accesscheckcallback */
+    protected $accesscheckcallback;
+
+    /**
+     * Class constructor
+     *
+     * @param string $name
+     * @param string $visiblename
+     * @param string $url
+     * @param callable $accesscheckcallback The callback method that will be executed to check whether user has access to
+     *     this page. The setting instance ($this) is passed as an argument to the callback. Should return boolean value
+     * @param bool $hidden
+     */
+    public function __construct(string $name, string $visiblename, string $url, callable $accesscheckcallback,
+            bool $hidden = false) {
+
+        $this->accesscheckcallback = $accesscheckcallback;
+
+        parent::__construct($name, $visiblename, $url, [], $hidden);
+    }
+
+    /**
+     * Determines if the current user has access to this external page based on access callback
+     *
+     * @return bool
+     */
+    public function check_access() {
+        return ($this->accesscheckcallback)($this);
+    }
+}

lib/upgrade.txt

@@ -52,6 +52,8 @@ information provided here is intended especially for developers.
   renamed to `is_listed()` and `get_not_listed()` respectively.
 * Method `mustache_helper_collection::strip_blacklisted_helpers()` has been deprecated and renamed to
   `strip_disallowed_helpers()`.
+* A new admin externalpage type `\core_admin\local\externalpage\accesscallback` for use in plugin settings is available that allows
+  a callback to be provided to determine whether page can be accessed.
 
 === 3.9 ===
 * Following function has been deprecated, please use \core\task\manager::run_from_cli().