Add and save custom meta data to fees in WooCommerce - php

Question

I'm adding a custom fees to WC with WC()->cart->add_fee() method.
My problem is that I'd like to add metadata to that fee item too. Preferably same time I'm adding the actual fee.
Apparently the WC_Order_Item_Fee Object is generated in the order creation only, so there seems to be no way to add FeeItem-specific metadata to custom fees.
Of course I could save this meta to session, but because add_fee doesn't return any identifier I have no idea which custom fee is actually which.
Any ideas how to solve this issue?
This is the code I use to add Fees:
add_filter('woocommerce_cart_calculate_fees', function (){
foreach( FeeChecker::getFees() as $fee )
{
$cart->add_fee("Added fee: ". $fee, 10 , true, $tax_class);
}
}

Answer 1

Note: In your code the $cart argument is missing from the hooked function and it's an action hook, but not a filter hook.
The WC_Cart method add_fee() doesn't allow to add custom meta data, so you will need to add it before on add_to_cart event or in WC_Session.
You can add custom meta data to WC_Order_Item_Fee when order is submitted using the following code example (using WC_Session to set and get the custom meta data in here):
// Add a custom cart fee
add_action( 'woocommerce_cart_calculate_fees', 'adding_cart_fees', 10, 1 );
function adding_cart_fees( $cart ){
$cart->add_fee(__("Added fee"), 10, true, '');
}
// Set Fee custom meta data in WC_Session
add_action( 'woocommerce_calculate_totals', 'calculate_totals_for_fees_meta_data', 10, 1 );
function calculate_totals_for_fees_meta_data( $cart ){
if ( is_admin() && ! defined( 'DOING_AJAX' ) )
return;
$fees_meta = WC()->session->get('fees_meta');
$update = false;
// Loop through applied fees
foreach( $cart->get_fees() as $fee_key => $fee ) {
// Set the fee in the fee custom meta data array
if( ! isset($fees_meta[$fee_key]) ){
$fees_meta[$fee_key] = 'some value';
$update = true;
}
}
// If any fee meta data doesn't exist yet, we update the WC_Session custom meta data array
if ( $update ) {
WC()->session->set('fees_meta', $fees_meta);
}
}
// Save fee custom meta data to WC_Order_Item_Fee.
add_action( 'woocommerce_checkout_create_order_fee_item', 'save_custom_met_data_to_fee_order_items', 10, 4 );
function save_custom_met_data_to_fee_order_items( $item, $fee_key, $fee, $order ) {
// Get fee meta data from WC_Session
$fees_meta = WC()->session->get('fees_meta');
// If fee custom meta data exist, save it to fee order item
if ( isset($fees_meta[$fee_key]) ) {
$item->update_meta_data( 'custom_key', $fees_meta[$fee_key] );
}
}
// Remove Fee meta data from WC_Session.
add_action( 'woocommerce_checkout_create_order', 'remove_fee_custom_met_data_from_wc_session', 10, 2 );
function remove_fee_custom_met_data_from_wc_session( $order, $data ) {
$fees_meta = WC()->session->__unset('fees_meta');
}
Code goes in function.php file of your active child theme (or active theme). Tested and works.
The custom meta data is saved to WC_Order_Item_Fee and you can get it using something like:
// Get an instance of the WC_Order Object (if needed)
$order = wc_get_order( $order_id );
// loop through fee order items
foreach ( $order->get_items('fee') as $fee_key => $item ) {
// Get the fee custom meta data
$fee_custom_meta = $item->get_meta('custom_key');
if ( $fee_custom_meta ) {
// Display the custom meta data value
echo '<p>' . $fee_custom_meta . '</p>';
}
}

Answer 2

A somewhat hacky way is to use the ID field of the fee item to link to data stored somewhere else.
$args = array(
'id' => $data_id,
'name' => $name,
'amount' => (float) $amount,
'taxable' => false,
'tax_class' => '',
);
$cart->fees_api()->add_fee( $args );
Later you can use the hook woocommerce_checkout_create_order_fee_item to fetch the data and populate the order item fee. In my case:
add_action( 'woocommerce_checkout_create_order_fee_item', array( $this, 'create_order_fee_item' ), 20, 4 );
public function create_order_fee_item( $item, $fee_key, $fee, $order ) {
$item->add_meta_data( 'product_id', $fee_key, true );
}

Answer 3

It seems I overlooked WC_Cart->fees_api
In there I have method that actually returns the created Fee so I know the exact Fee in woocommerce_checkout_create_order_fee_item action
Edit: This code was originally mostly done by LoicTheAztec. I edited it to fit my particular use case and posted it as solution. Unfortunatelly he deleted his post which could have been beneficial to others.
// Add cod fee
add_action('woocommerce_cart_calculate_fees', function ( $cart ){
if ( is_admin() && ! defined( 'DOING_AJAX' ) )
return;
//Make sure it's the right payment method
if( WC()->session->chosen_payment_method == "cod"){
$tax_class = '';
$amount = 5;
$session_data = [];
foreach( $cart->get_shipping_packages() as $package)
{
$fee = $cart->fees_api()->add_fee(
array(
'name' => "Additional cost: ".$package['custom_data'],
'amount' => (float) $amount,
'taxable' => true,
'tax_class' => $tax_class,
)
);
$session_data [ $fee->id ] = $package['custom_data'];
}
WC()->session->set('COD_fee_meta', $session_data);
}
}, 10, 2);
// Save fee custom meta data to WC_Order_Item_Fee.
add_action( 'woocommerce_checkout_create_order_fee_item', function ( $item, $fee_key, $fee, $order ) {
// Get fee meta data from WC_Session
$fees_meta = WC()->session->get('COD_fee_meta');
// If fee custom meta data exist, save it to fee order item
if ( isset($fees_meta[$fee_key]) ) {
$item->update_meta_data( '_custom_data', $fees_meta[$fee_key] );
}
}, 10, 4 );
// Remove Fee meta data from WC_Session.
add_action( 'woocommerce_checkout_create_order', function ( $order, $data ) {
WC()->session->__unset('COD_fee_meta');
}, 10, 2 );