Ndtyjky

We are a tennis and squash club running nBill, an invoicing system that is no longer actively supported. I nursed it on upgrade from PHP 5 to 7 but on further upgrading to PHP7.1 the application does not load and I get the following fatal error message:

Fatal error: Only variables can be passed by reference in /xxxxxxxx/public_html/administrator/components/com_nbill/classes/base/data_mapper.php on line 98.

I understand what is wrong but I cannot solve it, it is beyond my limited knowledge of PHP. Removing the section of code enables the application to work and then it seems to work fine.

The statement at fault is:

  $string = nbf_common::get_param(array($key=>$value), $key, '', false, (string)@$col[0]->encode_html != "false", (string)@$col[0]->allow_html == "true", (string)@$col[0]->allow_html == "true");

The full section of code reads:

     * Return an appropriate string to use for the value in an SQL statement

     (escaped, or intval'd as appropriate for the data type, based on the XML



    schema file, if found, or just treated as a string [and escaped] otherwise)



        * @param string $key Column name

        * @param mixed $value Literal value

        */

        protected function getValueSqlString($key, $value)

        {

            $string = "";



            if ($this->schema)

            {

                $col = $schema->xpath("columns/column[@name='$key']");

                switch (@$col->type)

                {

                    case "int":

                    case "tinyint":

                    case "smallint":

                    case "mediumint":

                    case "bigint":

                    case "integer":

                    case "long":

                        $string = strval(intval($value));

                        break;

                    default:

                        $string = nbf_common::get_param(array($key=>$value),

 $key, '', false, (string)@$col[0]->encode_html != "false", 

(string)@$col[0]->allow_html == "true", 

(string)@$col[0]->allow_html == "true");

                        break;

                }

            }



            if (!$string) {

                $string = "'" . $this->db->getEscaped($value) . "'";

            }

            return $string;

        }



        /**

Any help most gratefully received. Note we are actively seeking a replacement invoicing system and are trialling CBSubs.

CBSheen

<?php

$array = array($key=>$value);

$string = nbf_common::get_param(strtolower(array_pop($array)), $key, '', false, (string)@$col[0]->encode_html != "false", (string)@$col[0]->allow_html == "true", (string)@$col[0]->allow_html == "true");

Try the above code. I am not a joomla expert but based on your error i think the problem is when you try to pass an array inside the get_param function.

nbf_common::get_param()

Look this function up, see which of the params is passed by reference, then check if the value actually passed as that parameter can be passed as reference. It is probably what pr1nc3 says.