Multiply shipping cost in WooCommerce - php

Question

I've tried to multiply shipping cost depending on how many pallets are in order. I think filter is wrong or something. It just doesnt change shipping price.
$calc = ceil($a+$b / 8); $a > is quantity of pallets, $b > is quantity of units what calculates how many pallets.
My code (function.php):
add_filter( 'woocommerce_cart_shipping_total', 'woocommerce_cart_shipping_total_filter_callback', 11, 2 );
function woocommerce_cart_shipping_total_filter_callback( $total, $cart )
{
if ( is_admin() && ! defined( 'DOING_AJAX' ) )
return;
if ( 0 < $cart->get_shipping_total() ) {
if ( $cart->display_prices_including_tax() ) {
$a = 0;
$b = 0;
foreach( WC()->cart->get_cart() as $cart_item ){
if (!empty(get_post_meta($cart_item['variation_id'], '_number_field', true))) {
$a += $cart_item['quantity'];
} else {
$atk = strstr(get_post_meta($cart_item['variation_id'], '_alus_al', true), 'tk', true);
$b += ceil($cart_item['quantity'] / $atk);
}
}
$calc = ceil($a+$b / 8); // 8 pallets maximum
$total = wc_price( ( $cart->shipping_total + $cart->shipping_tax_total ) * $calc );
if ( $cart->shipping_tax_total > 0 && ! wc_prices_include_tax() ) {
$total .= ' <small class="tax_label">' . WC()->countries->inc_tax_or_vat() . '</small>';
}
} else {
$a = 0;
$b = 0;
foreach( WC()->cart->get_cart() as $cart_item ){
if (!empty(get_post_meta($cart_item['variation_id'], '_number_field', true))) {
$a += $cart_item['quantity'];
} else {
$atk = strstr(get_post_meta($cart_item['variation_id'], '_alus_al', true), 'tk', true);
$b += ceil($cart_item['quantity'] / $atk);
}
}
$calc = ceil($a+$b / 8); // 8 pallets maximum
$total = wc_price( $cart->shipping_total * $calc );
if ( $cart->shipping_tax_total > 0 && wc_prices_include_tax() ) {
$total .= ' <small class="tax_label">' . WC()->countries->ex_tax_or_vat() . '</small>';
}
}
}
return $total;
}
My problem is that it doesnt change shipping cost. So I excpect it doesnt work.

Answer 1

Like user #LoicTheAztec mentioned I should use woocommerce_package_rates to override custom prices for shipping plugin.
add_filter( 'woocommerce_package_rates', 'custom_shipping_costs', 20, 2 );
function custom_shipping_costs( $rates, $package ) {
$a = 0;
$b = 0;
foreach( WC()->cart->get_cart() as $cart_item ){
if (!empty(get_post_meta($cart_item['variation_id'], '_number_field', true))) {
$a += $cart_item['quantity'];
} else {
$atk = strstr(get_post_meta($cart_item['variation_id'], '_alus_al', true), 'tk', true);
$atb = $atk / 2;
if ($cart_item['quantity'] < $atb) {
$b += 0;
} else {
$b += ceil($cart_item['quantity'] / $atk);
}
}
}
$tt = $a+$b;
$calc = ceil($tt / 8);
foreach( $rates as $rate_key => $rate ){
// Excluding free shipping methods
if( $rate->method_id != 'free_shipping'){
// Set rate cost
$rates[$rate_key]->cost = $rates[$rate_key]->cost * $calc;
// Set taxes rate cost (if enabled)
$taxes = array();
foreach ($rates[$rate_key]->taxes as $key => $tax){
if( $rates[$rate_key]->taxes[$key] > 0 )
$taxes[$key] = $new_cost * $tax_rate;
}
$rates[$rate_key]->taxes = $taxes;
}
}
return $rates;
}