--- /dev/null
+<?php
+/**
+ * A concrete filter for validating the username. This filter may intercept the
+ * filter chain if no username is given or if the supplied username has an
+ * invalid form. It could also intercept the filter chain if the username is
+ * already taken.
+ *
+ * @author Roland Haeder <webmaster@ship-simu.org>
+ * @version 0.0.0
+ * @copyright Copyright(c) 2007, 2008 Roland Haeder, this is free software
+ * @license GNU GPL 3.0 or any newer version
+ * @link http://www.ship-simu.org
+ *
+ * This program 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.
+ *
+ * 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+class UserNameValidatorFilter extends BaseFrameworkSystem implements Filterable {
+ /**
+ * Private constructor
+ *
+ * @return void
+ */
+ protected function __construct () {
+ // Call parent constructor
+ parent::__construct(__CLASS__);
+
+ // Set part description
+ $this->setObjectDescription("A filter for username validation");
+
+ // Create unique ID number
+ $this->createUniqueID();
+
+ // Clean up a little
+ $this->removeNumberFormaters();
+ $this->removeSystemArray();
+ }
+
+ /**
+ * Creates an instance of this filter class
+ *
+ * @return $filterInstance An instance of this filter class
+ */
+ public final static function createUserNameValidatorFilter () {
+ // Get a new instance
+ $filterInstance = new UserNameValidatorFilter();
+
+ // Return the instance
+ return $filterInstance;
+ }
+
+ /**
+ * Executes the filter with given request and response objects
+ *
+ * @param $requestInstance An instance of a class with an Requestable interface
+ * @param $responseInstance An instance of a class with an Responseable interface
+ * @return void
+ */
+ public function execute (Requestable $requestInstance, Responseable $responseInstance) {
+ // Get username from request
+ $userName = $requestInstance->getRequestElement('username');
+
+ // Is the username set?
+ if (is_null($userName)) {
+ // Not found in form so stop the filtering process
+ $requestInstance->requestIsValid(false);
+
+ // Set a message for the response
+ $responseInstance->addFatalMessage('username_unset');
+
+ // Abort here
+ return false;
+ } elseif (empty($userName)) {
+ // Empty field!
+ $requestInstance->requestIsValid(false);
+
+ // Set a message for the response
+ $responseInstance->addFatalMessage('username_empty');
+
+ // Abort here
+ return false;
+ } elseif ($this->ifUserNameIsTaken($userName)) {
+ // Username is already taken
+ $requestInstance->requestIsValid(false);
+
+ // Set a message for the response
+ $responseInstance->addFatalMessage('username_taken');
+
+ // Abort here
+ return false;
+ }
+ }
+
+ /**
+ * Check wether the username as already been taken
+ *
+ * @param $userName Username to check for existence
+ * @return $alreadyTaken Wether the username has been taken
+ */
+ private function ifUserNameIsTaken ($userName) {
+ // Default is already taken
+ $alreadyTaken = true;
+
+ // Try to create a user instance
+ try {
+ // If this instance is created then the username *does* exist
+ $userInstance = User::createUserByUsername($userName);
+ } catch (UsernameMissingException $e) {
+ // Okay, this user is missing!
+ $alreadyTaken = false;
+ } catch (FrameworkException $e) {
+ // Something bad happend
+ ApplicationEntryPoint::app_die(sprintf("Exception: %s", $e->__toString()));
+ }
+
+ // Return the result
+ return $alreadyTaken;
+ }
+}
+
+// [EOF]
+?>