Fatal PHP error when not checking for “cart” method on WC()

Resolved robertstaddon
(@robertstaddon)

2 years, 6 months ago

Under certain circumstances when your plugin has the “Replace cart url” setting enabled and is being used with other select themes and plugins, the following fatal error is generated when a page is being saved:

PHP Fatal error: Uncaught TypeError: method_exists(): Argument #1 ($object_or_class) must be of type object|string, null given in /public_html/wp-content/plugins/woocommerce-direct-checkout/lib/view/frontend/class-general.php:115

This problem is easily solved by simply checking if the ‘cart’ method exists on WC() before checking if the ‘is_empty’ method exists on WC()->cart:

if ( method_exists( WC(), 'cart' ) && method_exists( WC()->cart, 'is_empty' ) && WC()->cart->is_empty() ) {

Would you mind updating line 115 of /woocommerce-direct-checkout/lib/view/frontend/class-general.php with this extra check? It would make your plugin more robust and work better with specialized combinations of plugins and themes. Thank you!

Viewing 9 replies - 1 through 9 (of 9 total)

Plugin Support jmatiasmastro
(@jmatiasmastro)

2 years, 6 months ago

@robertstaddon Hello mate, could you please tell us which version of our plugin you are using?

Regards.

Thread Starter robertstaddon
(@robertstaddon)

2 years, 6 months ago

I’m using the latest v3.2.8. Out of the box it works fine. But with certain other plugins installed that utilize WordPress hooks (such as in the backend or REST API), your plugin can trigger a PHP fatal error when the replace_cart_url() function runs. This is because WC()->cart can be null.

As you can see in this WooCommerce GitHub ticket, WooCommerce says that “we don’t load the cart in backend or REST API. So you need to check if is not null first, or even if get_cart is callable.” https://github.com/woocommerce/woocommerce/issues/23758

And this Stack Overflow article (and others that I could reference) reiterate that you need to check that the cart object even exists as well as that it is not empty: https://stackoverflow.com/questions/64425146/avoid-error-call-to-a-member-function-get-cart-in-woocommerce-function

rodcul
(@rodcul)

2 years, 6 months ago

@robertstaddon I just spent nearly 2 hours trying to figure out why I was getting this issue on one site but not another, thank you.

@jmatiasmastro could you update the plugin? Thanks!

Plugin Support jmatiasmastro
(@jmatiasmastro)

2 years, 6 months ago

@rodcul

@robertstaddon

Hello mate, we inform you that we have sent this ticket to our development team for investigation.

Regards.

kionez
(@kionez)

2 years, 6 months ago

Same here with version 3.2.9.
I think that some gateway plugin that creates the order before redirecting the user to the payment page (i.e. cartasi-x-pay) destroy the cart object.
I fixed it adding a simple !empty(WC()->cart) && to the if conditions at line 115 in lib/view/frontend/class-general.php.

Plugin Author quadlayers
(@quadlayers)

2 years, 6 months ago

Hello guys

Please test version 3.3.0

kionez
(@kionez)

2 years, 6 months ago

It works fine, the error disappeared and everything works. Thanks!

Plugin Author quadlayers
(@quadlayers)

2 years, 6 months ago

thanks for the update @kionez

we will really appreciate if you can leave your review here

https://ww.wp.xz.cn/support/plugin/woocommerce-direct-checkout/reviews/?filter=5

best regards

Thread Starter robertstaddon
(@robertstaddon)

2 years, 6 months ago

The update to 3.3.0 solved the problem for me as well!

Viewing 9 replies - 1 through 9 (of 9 total)

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