plugin to limit number of registered users

plugins/UserLimitPlugin.php

@@ -0,0 +1,92 @@
+<?php
+/**
+ * StatusNet, the distributed open-source microblogging tool
+ *
+ * Plugin to limit number of users that can register (best for cloud providers)
+ *
+ * PHP version 5
+ *
+ * LICENCE: This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @category  Action
+ * @package   StatusNet
+ * @author    Evan Prodromou <evan@status.net>
+ * @copyright 2009 StatusNet Inc.
+ * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
+ * @link      http://status.net/
+ */
+
+if (!defined('STATUSNET')) {
+    exit(1);
+}
+
+/**
+ * Plugin to limit number of users that can register (best for cloud providers)
+ *
+ * For cloud providers whose freemium model is based on how many
+ * users can register. We use it on the StatusNet Cloud.
+ *
+ * @category Plugin
+ * @package  StatusNet
+ * @author   Evan Prodromou <evan@status.net>
+ * @license  http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
+ * @link     http://status.net/
+ *
+ * @seeAlso  Location
+ */
+
+class UserLimitPlugin extends Plugin
+{
+    public $maxUsers = null;
+
+    function onStartUserRegister(&$user, &$profile)
+    {
+        $this->_checkMaxUsers();
+        return true;
+    }
+
+    function onStartRegistrationTry($action)
+    {
+        $this->_checkMaxUsers();
+        return true;
+    }
+
+    function _checkMaxUsers()
+    {
+        if (!is_null($this->maxUsers)) {
+
+            $cls = new User();
+
+            $cnt = $cls->count();
+
+            if ($cnt >= $this->maxUsers) {
+                $msg = sprintf(_('Cannot register; maximum number of users (%d) reached.'),
+                               $this->maxUsers);
+
+                throw new ClientException($msg);
+            }
+        }
+    }
+
+    function onPluginVersion(&$versions)
+    {
+        $versions[] = array('name' => 'UserLimit',
+                            'version' => STATUSNET_VERSION,
+                            'author' => 'Evan Prodromou',
+                            'homepage' => 'http://status.net/wiki/Plugin:UserLimit',
+                            'description' =>
+                            _m('Limit the number of users who can register.'));
+        return true;
+    }
+}