在woocommerce中设置购物车数量与foreach无限循环

Question

I'm trying to programmatically set the quantity of items currently in my Woocommerce cart using the following code (I've entered the number 42 here as a test - dynamic value will go in once it stops misbehaving).

The code I'm using is as follows:

function update_quantity_in_cart( $cart ) {

if( ! is_cart() ) {
return;
}  

// Iterate through each cart item
foreach( $cart->get_cart_contents() as $item_key=>$cart_item ) {
  var_dump($cart);

  if ( isset( $cart_item['quantity'] )){
    $cart->set_quantity( $item_key, 42 ); // I think this line is causing the problem
  }
} // end foreach 
}

add_action( 'woocommerce_before_calculate_totals', 'update_quantity_in_cart', 5, 1 );

Everything is good until I add the line "$cart->set_quantity( $item_key, 42 );" which throws up a "Fatal error: Uncaught Error: Maximum function nesting level of '256' reached, aborting!" error. For some reason adding this line seems to make it keep looping infinitely.

A var_dump() for $cart returns an object including public 'cart_contents' (the bit I'm trying to get), public 'removed_cart_contents', public 'applied_coupons' and more besides. My instinct is that it's trying to update the quantity for all of these as opposed to just cart_contents. If that's the case, is there a way of isolating cart contents and just returning those. https://docs.woocommerce.com/wc-apidocs/class-WC_Cart.html suggests get_cart_contents() should do it but apparently not.

Anything obvious I'm doing wrong here?

Answer 1

There is some mistakes and missing parts in your code. Try this:

add_action( 'woocommerce_before_calculate_totals', 'update_quantity_in_cart' );
function update_quantity_in_cart( $cart ) {
    if ( is_admin() && !defined('DOING_AJAX') )
        return;

    if ( did_action( 'woocommerce_before_calculate_totals' ) >= 2 )
        return;

    foreach( $cart->get_cart() as $cart_item_key => $cart_item ) {
        $cart->set_quantity( $cart_item_key, 42 );
    }
}

Code goes in function.php file of your active child theme (or active theme). Tested and work.