Added a first cut at a session class, just to support adding messages to

the session and retrieving them for display.

htdocs/lib/session.php

+<?php
+/**
+ * This program is part of Mahara
+ *
+ *  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 2 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, write to the Free Software
+ *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+ *
+ * @package    mahara
+ * @subpackage core or plugintype/pluginname
+ * @author     Nigel McNie <nigel@catalyst.net.nz>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL
+ * @copyright  (C) 2006,2007 Catalyst IT Ltd http://catalyst.net.nz
+ *
+ */
+
+defined('INTERNAL') || die();
+
+
+/**
+ * The session class handles user sessions and session messages.
+ *
+ * Messages are stored in the session and are displayed the next time
+ * a page is displayed to a user, even over multiple requests (but not
+ * over multiple sessions)
+ *
+ * This is a _really rough_ first cut, in order to support messaging.
+ */
+class Session {
+
+    function __construct() {
+        session_start();
+        if (!$_SESSION) {
+            $_SESSION = array();
+        }
+    }
+
+    /**
+     * Adds a message that indicates something was successful
+     *
+     * @param string $message The message to add
+     * @param boolean $escape Whether to HTML escape the message
+     */
+    public function add_ok_msg($message, $escape=true) {
+        if ($escape) {
+            $message = htmlspecialchars($message, ENT_COMPAT, 'UTF-8');
+            $message = str_replace('  ', '&nbsp; ', $message);
+        }
+        $_SESSION['messages'][] = array('type' => 'ok', 'msg' => $message);
+    }
+
+    /**
+     * Adds a message that indicates an informational message
+     *
+     * @param string $message The message to add
+     * @param boolean $escape Whether to HTML escape the message
+     */
+    public function add_info_msg($message, $escape=true) {
+        if ($escape) {
+            $message = htmlspecialchars($message, ENT_COMPAT, 'UTF-8');
+            $message = str_replace('  ', '&nbsp; ', $message);
+        }
+        $_SESSION['messages'][] = array('type' => 'info', 'msg' => $message);
+    }
+
+    /**
+     * Adds a message that indicates a failure to do something
+     *
+     * @param string $message The message to add
+     * @param boolean $escape Whether to HTML escape the message
+     */
+    public function add_err_msg($message, $escape=true) {
+        if ($escape) {
+            $message = htmlspecialchars($message, ENT_COMPAT, 'UTF-8');
+            $message = str_replace('  ', '&nbsp; ', $message);
+        }
+        $_SESSION['messages'][] = array('type' => 'err', 'msg' => $message);
+    }
+
+    /**
+     * Builds HTML that represents all of the messages and returns it.
+     *
+     * This is designed to let smarty templates hook in any session messages.
+     *
+     * Calling this function will destroy the session messages that were
+     * rendered, so they do not inadvertently get displayed again.
+     *
+     * @return string The HTML representing all of the session messages.
+     */
+    public function render_messages() {
+        $result = '';
+        foreach ($_SESSION['messages'] as $data) {
+            if ($data['type'] == 'ok') {
+                $color = 'green';
+            }
+            elseif ($data['type'] == 'info') {
+                $color = '#990;';
+            }
+            else {
+                $color = 'red';
+            }
+            $result .= '<div style="color:' . $color . ';">' . $data['msg'] . '</div>';
+        }
+        $_SESSION['messages'] = array();
+        return $result;
+    }
+
+}
+
+/**
+ * A smarty callback to insert page messages
+ *
+ * @return string The HTML represening all of the session messages.
+ */
+function insert_messages() {
+    global $SESSION;
+    return $SESSION->render_messages();
+}
+
+$SESSION =& new Session;
+
+?>