New cart item price based on a GET parameter in Woocommerce - php

Question

There is a field on the main page with a numerical parameter:
length
and button - add to cart like:
add to cart
I would like to calculate the price of the goods from this parameter.
I understood how to change the price when adding to the basket but I can not understand how to transfer the numerical parameter of the field to the function in functions.php
The biggest problem is that the field is not on the single product page.
I think that you can pass a parameter through a link by type:
add to cart
But I could not get it in function yet.
add_action( 'woocommerce_before_shipping_calculator', 'add_custom_price' );
global $woocommerce;
foreach ( WC()->cart->get_cart() as $cart_item_key => $cart_item ) {
if($cart_item['data']->id == ####){
$original_price = $cart_item['data']->price;
$length = $_GET('length');
$new_price = $original_price + $length;
$cart_item['data']->set_price($new_price);
}
}
}

Answer 1

Using the following 2 hooked functions will allow you to set a new cart item price calculated on a Get "length" parameter this way:
// Set custom text and calculated price as custom cart data in the cart item
add_filter( 'woocommerce_add_cart_item_data', 'save_new_price_in_cart_object', 30, 3 );
function save_new_price_in_cart_object( $cart_item_data, $product_id, $variation_id ) {
if( ! isset( $_GET['length'] ) )
return $cart_item_data;
// Get an instance of the WC_Product object
$product = $variation_id > 0 ? wc_get_product($variation_id) : wc_get_product($product_id);
$product_price = (float) $product->get_price(); // Get the product price
// Get lenght
$length = esc_attr( $_GET['length'] );
// Set the new calculated price as custom cart data for the cart item
$cart_item_data['custom_data']['price'] = $product_price + $length;
return $cart_item_data;
}
// Set the new calculated price of the cart item
add_action( 'woocommerce_before_calculate_totals', 'set_new_cart_item_price', 90, 1 );
function set_new_cart_item_price( $cart ) {
if ( is_admin() && ! defined( 'DOING_AJAX' ) )
return;
if ( did_action( 'woocommerce_before_calculate_totals' ) >= 2 )
return;
foreach ( $cart->get_cart() as $cart_item ) {
if( isset( $cart_item['custom_data']['price'] ) ) {
// Get the new calculated price
$new_price = (float) $cart_item['custom_data']['price'];
// Set the new calculated price
$cart_item['data']->set_price( $new_price );
}
}
}
Code goes in function.php file of your active child theme (or active theme).
Tested and works