public function verify_unique_page() { $file = $this->settings['file']; $parent = $this->settings['parent']; // Register top level page if (!$parent) { if (isset(self::$registered_pages[$file])) { Incorrect_Syntax_Exception::raise('Page "' . $file . '" already registered'); } self::$registered_pages[$file] = array(); return; } // Register sub-page if (!isset(self::$registered_pages[$parent])) { self::$registered_pages[$parent] = array($file); } elseif (in_array($file, self::$registered_pages[$parent])) { Incorrect_Syntax_Exception::raise('Page "' . $file . '" with parent "' . $parent . '" is already registered. Please set a different file name using setup()'); } else { self::$registered_pages[$parent][] = $file; } }