phpbb\log\log::delete PHP Method

    public function delete($mode, $conditions = array())
    {
        switch ($mode) {
            case 'admin':
                $log_type = LOG_ADMIN;
                break;
            case 'mod':
                $log_type = LOG_MOD;
                break;
            case 'user':
                $log_type = LOG_USERS;
                break;
            case 'users':
                $log_type = LOG_USERS;
                break;
            case 'critical':
                $log_type = LOG_CRITICAL;
                break;
            default:
                $log_type = false;
        }
        /**
         * Allows to modify log data before we delete it from the database
         *
         * NOTE: if sql_ary does not contain a log_type value, the entry will
         * not be deleted in the database. So ensure to set it, if needed.
         *
         * @event core.delete_log
         * @var	string	mode			Mode of the entry we log
         * @var	string	log_type		Type ID of the log (should be different than false)
         * @var	array	conditions		An array of conditions, 3 different  forms are accepted
         * 								1) <key> => <value> transformed into 'AND <key> = <value>' (value should be an integer)
         *								2) <key> => array(<operator>, <value>) transformed into 'AND <key> <operator> <value>' (values can't be an array)
         *								3) <key> => array('IN' => array(<values>)) transformed into 'AND <key> IN <values>'
         *								A special field, keywords, can also be defined. In this case only the log entries that have the keywords in log_operation or log_data will be deleted.
         * @since 3.1.0-b4
         */
        $vars = array('mode', 'log_type', 'conditions');
        extract($this->dispatcher->trigger_event('core.delete_log', compact($vars)));
        if ($log_type === false) {
            return;
        }
        $sql_where = 'WHERE log_type = ' . $log_type;
        if (isset($conditions['keywords'])) {
            $sql_where .= $this->generate_sql_keyword($conditions['keywords'], '');
            unset($conditions['keywords']);
        }
        foreach ($conditions as $field => $field_value) {
            $sql_where .= ' AND ';
            if (is_array($field_value) && sizeof($field_value) == 2 && !is_array($field_value[1])) {
                $sql_where .= $field . ' ' . $field_value[0] . ' ' . $field_value[1];
            } else {
                if (is_array($field_value) && isset($field_value['IN']) && is_array($field_value['IN'])) {
                    $sql_where .= $this->db->sql_in_set($field, $field_value['IN']);
                } else {
                    $sql_where .= $field . ' = ' . $field_value;
                }
            }
        }
        $sql = 'DELETE FROM ' . LOG_TABLE . "\n\t\t\t\t\t{$sql_where}";
        $this->db->sql_query($sql);
        $this->add('admin', $this->user->data['user_id'], $this->user->ip, 'LOG_CLEAR_' . strtoupper($mode));
    }