WordPress at Your Fingertips
filter is not described

woocommerce_add_to_cart_sold_individually_found_in_cart filter-hook . WC 1.0

Force quantity to 1 if sold individually and check for existing item in cart.

Usage

add_filter( 'woocommerce_add_to_cart_sold_individually_found_in_cart', 'filter_function_name_8678', 10, 5 );
function filter_function_name_8678( $condition, $product_id, $variation_id, $cart_item_data, $cart_id ){
	// filter...

	return $condition;
}
$condition
-
$product_id
-
$variation_id
-
$cart_item_data
-
$cart_id
-

Where the hook is called

WC_Cart::add_to_cart()
woocommerce_add_to_cart_sold_individually_found_in_cart
woocommerce/includes/class-wc-cart.php 1149
$found_in_cart = apply_filters( 'woocommerce_add_to_cart_sold_individually_found_in_cart', $cart_item_key && $this->cart_contents[ $cart_item_key ]['quantity'] > 0, $product_id, $variation_id, $cart_item_data, $cart_id );

Where in WP core the hook is used WooCommerce

Usage not found.