How can we change this PHP function to work with PHP 8?

Question

Would anyone know how we can rewrite the following function to be compatible and work with PHP 8?

function wpsc_have_shipping_quote() {

    $has_quote = false;

    global $wpsc_cart;

    if ( $wpsc_cart->shipping_quote_count > 0 || count( $wpsc_cart->shipping_quotes ) > 0 ) {
        $has_quote = true;
    }

    return $has_quote;
}

What's wrong with that function as it stands? I'm not seeing anything jumping out at me. Are you getting an error when you use it? — Chris Haas, Jan 28 '22 at 18:01
Hi there, sorry forgot to post the error message, which is:Fatal error: Uncaught TypeError: count(): Argument #1 ($value) must be of type Countable|array, null given — Andy, Jan 28 '22 at 18:22
Before upgrading the PHP version of a site, always turn PHP errors completely on. This has been a warning since 7.2 with a plan to turn it into a full error in 8.0. — Chris Haas, Jan 28 '22 at 18:31
Thanks Chris, Luckily we're doing this in a test environment at the moment. Currently trying to upgrade from PHP7.4 to PHP8.0. The other section of code with the $value mentioned is: function wpsc_shipping_quote_value( $numeric = false ) { global $wpsc_cart; $value = apply_filters( 'wpsc_shipping_quote_value', $wpsc_cart->shipping_quote['value'] ); return ( $numeric ) ? $value : wpsc_currency_display( $value ); } — Andy, Jan 28 '22 at 18:34
Assuming `$wpsc_cart->shipping_quotes` is an array and not an exotic object, you can simply check for `!empty($wpsc_cart->shipping_quotes)` which will return true if 1 or more, and false on 0 or null. — Markus AO, Jan 28 '22 at 18:56

score 2 · Accepted Answer · answered Jan 28 '22 at 19:19

You don't have to count the array just to see if it has anything in it. When you use ||, the values being compared will be converted to booleans, and shipping_quotes will evaluate to false whether it is an empty array or a null.

function wpsc_have_shipping_quote() {    

    global $wpsc_cart;

    return $wpsc_cart->shipping_quote_count || $wpsc_cart->shipping_quotes;
}

This should work in any PHP version.

Rodrigo Kravetz · Answer 2 · 2022-01-28T19:40:43.433

Andy. Kind regards.

In PHP 8.+, count() does not accept null values anymore, it was already throwing warnings since PHP 7.2 if I recall correctly. Therefore the code is failing exactly here:

count( $wpsc_cart->shipping_quotes ) > 0

because in some situations $wpsc_cart->shipping_quotes may be null (it was not set).

You can use the new PHP 8 null coalescing to check if the value is null, and if it is null, you can provide an empty array []. So change the line:

if ( $wpsc_cart->shipping_quote_count > 0 || count( $wpsc_cart->shipping_quotes ) > 0 ) {

To:

if ( $wpsc_cart->shipping_quote_count > 0 || count( $wpsc_cart->shipping_quotes ?? [] ) > 0 ) {

Null coalescing operator was introduced with PHP 7 though. – Markus AO Jan 28 '22 at 18:53 — Markus AO, Jan 28 '22 at 18:53

How can we change this PHP function to work with PHP 8?

2 Answers2