Strict Standards: Declaration of ' ' should be compatible with ' '

Question

I just installed woocommerce 2.0 (on Wordpress) on PHP 5.4, and I got this:

Strict Standards: Declaration of WC_Gateway_BACS::process_payment() should be compatible with WC_Payment_Gateway::process_payment() in D:\my\path\to\htdocs\wordpress\plugins\woocommerce\classes\gateways\bacs\class-wc-gateway-bacs.php on line...

I check the files and found that WC_Payment_Gateway have no method process_payment(). I need to know how to resolve this (not by setting error_reporting()).

What is Strict Standards in PHP exactly?
In what condition so we get that error?

Answer 1

WC_Payment_Gateway is defined in abstract-wc-payment-gateway.php and declares a method

function process_payment() {}

while WC_Gateway_BACS defines it as

function process_payment( $order_id ) { ...

(maybe you mixed up WC_Payment_Gateway and WC_Payment_Gateways).

So, different signature (0 parameters vs 1 parameter) -> strict error.
Since it seems* to be used always with one parameter you could change

function process_payment() {}

to

function process_payment($order_id) {}

---

(*) keep in mind I know of woocommerce only since the last five minutes, so don't take my word for it.

Answer 2

Quote from PHP Manual

In PHP 5 a new error level E_STRICT is available. Prior to PHP 5.4.0 E_STRICT was not >included within E_ALL, so you would have to explicitly enable this kind of error level in >PHP < 5.4.0. Enabling E_STRICT during development has some benefits. STRICT messages >provide suggestions that can help ensure the best interoperability and forward >compatibility of your code. These messages may include things such as calling non-static >methods statically, defining properties in a compatible class definition while defined in >a used trait, and prior to PHP 5.3 some deprecated features would issue E_STRICT errors >such as assigning objects by reference upon instantiation.

You are receiving this error because WC_Gateway_BACS::process_payment() declaration is different than WC_Payment_Gateway::process_payment() (might be not the same amount of parameters etc). If WC_Payment_Gateway has no method process_payment, check it's parent class :)

Also, if you want to disable STRICT errors, add ^ E_STRICT to your error reporting configuration, for example:

error_reporting(E_ALL ^ E_STRICT);