first commit

code/web/backend/application/core/Session.php

@@ -0,0 +1,75 @@
+<?php
+
+/**
+ * Session class
+ *
+ * handles the session stuff. creates session when no one exists, sets and gets values, and closes the session
+ * properly (=logout). Not to forget the check if the user is logged in or not.
+ */
+class Session
+{
+    /**
+     * starts the session
+     */
+    public static function init()
+    {
+        // if no session exist, start the session
+        if (session_id() == '') {
+            session_start();
+        }
+    }
+
+    /**
+     * sets a specific value to a specific key of the session
+     *
+     * @param mixed $key key
+     * @param mixed $value value
+     */
+    public static function set($key, $value)
+    {
+        $_SESSION[$key] = $value;
+    }
+
+    /**
+     * gets/returns the value of a specific key of the session
+     *
+     * @param mixed $key Usually a string, right ?
+     * @return mixed the key's value or nothing
+     */
+    public static function get($key)
+    {
+        if (isset($_SESSION[$key])) {
+            return $_SESSION[$key];
+        }
+    }
+
+    /**
+     * adds a value as a new array element to the key.
+     * useful for collecting error messages etc
+     *
+     * @param mixed $key
+     * @param mixed $value
+     */
+    public static function add($key, $value)
+    {
+        $_SESSION[$key][] = $value;
+    }
+
+    /**
+     * deletes the session (= logs the user out)
+     */
+    public static function destroy()
+    {
+        session_destroy();
+    }
+
+    /**
+     * Checks if the user is logged in or not
+     *
+     * @return bool user's login status
+     */
+    public static function userIsLoggedIn()
+    {
+        return (Session::get('user_logged_in') ? true : false);
+    }
+}