Weird issue with PHP on localhost vs test server (apache2) - php

Question

I am working on a website running WordPress and woocommerce
I have a custom function to add stuff to the cart which is the following:
function custom_add_products_to_cart(){
WC()->cart->empty_cart();
$request_body = file_get_contents('php://input');
$decoded = json_decode($request_body);
$cartElements = $decoded->addToCart;
foreach ( $cartElements as $product_id ) {
WC()->cart->add_to_cart( $product_id );
}
if ( $decoded->Uid ) {
WC()->session->set( 'uid', $decoded->Uid );
}
die();
};
This is quite a straightforward function. All it does is iterating through a list of products id and launching the default Woocommerce add to cart function.
The issue I've got is that this works perfectly fine on my localhost (also debugging it ut behaves just like expected) but when I try it on a test server it doesn't work.
The function is firing (i tried to print some messages) but the cart is not emptying and the new products are not added.
I check the code, commit and revision, and everything is correct.
What else can it be?
My last thought was on the version of PHP:
my localhost runs 7.1.2 while the test server runs 7.0.22 - can it be the PHP version or not? any idea on what else I could try?
Sorry if I cannot provide much more details but unfortunately there's not much more to add...
Also, I am not posting this to WordPress community for now as I think it's not a WordPress related stuff (nor woocommerce) but rather PHP code (maybe my function is somehow wrong?) or PHP version
Thanks in advance to everyone

Answer 1

i think the problem is here
file_get_contents('php://input');
depending on your PHP configuration, maybe you need to change the allow_url_fopen setting in you php.ini.
You have two ways of getting around it without changing php.ini, one of them is to use fsockopen(), and the other is to use cURL.
I recommend using cURL over file_get_contents() anyways, since it was built for this.

Answer 2

At the end i simply solve this by calling two functions:
the first one empties the cart:
function empty_cart(){
WC()->cart->empty_cart();
}
and the second one carries on adding to the cart:
function custom_add_products_to_cart(){
$request_body = file_get_contents('php://input');
$decoded = json_decode($request_body);
$cartElements = $decoded->addToCart;
foreach ( $cartElements as $product_id ) {
WC()->cart->add_to_cart( $product_id );
}
if ( $decoded->Uid ) {
WC()->session->set( 'uid', $decoded->Uid );
}
die();
};
and it now works properly.