make add/remove starter buttons date sensitive

homepage/participo/lib/participoLib/participo.php

@@ -23,6 +23,15 @@ class participo
 		return (isset($_SESSION) && array_key_exists('login', $_SESSION) && $_SESSION['login'] == true);
 	}
 
+	public static function getSessionUserId()
+	{
+		$userId = null;
+		if (isset($_SESSION) && array_key_exists('user', $_SESSION) && array_key_exists('userId', $_SESSION['user'])) {
+			$userId = $_SESSION['user']['userId'];
+		}
+		return $userId;
+	}
+
 	/** Remove all login data from the session data
 	 *
 	 * @return void
@@ -541,3 +550,17 @@ function getHtmlSquareDate($date = null)
 			. '<div style="font-size: small">' . $year . '</div>'
 		. '</div>';
 }
+
+/**
+ * filter_var for a (db)id
+ *
+ * check for valid id; null is default; only values > 0 are excepted
+ *
+ * @param [type] $id
+ * @retval int>0 filtered id
+ * @retval null sth. went wrong
+ */
+function filterId($id)
+{
+	return filter_var($id, FILTER_VALIDATE_INT, ['options' => ['default' => null, 'min_range' => 1]]);
+}