How to programatically charge extra fees in WooCommerce

Published:31 December 2022/ in WooCommerce, WordPress

How to programatically charge extra fees in WooCommerce

,

In this tutorial we’ll go through a basic example of how to programatically create and charge extra fees in WooCommerce. We will create a basic options page to allow admin users the ability to add extra shipping fees to products based on specific taxonomies. To do this, we will customise the functions.php template file. For real-world use it is recommended that a plugin with separate functions be created.

As this functionality is based off of adding extra shipping fees – we will ensure that custom fees are disregarded if ‘local pickup’ is selected as a shipping option. We will also ensure that custom fees are added to every item assigned to the taxonomy term (e.g. if a user adds two products to the cart that have a fee associated, the fee is added twice. The same goes for if it is the same item with more than one quantity).

Tutorial Contents

Tools required for this tutorial

To follow the steps in this tutorial you’ll need the following:

  • WordPress (tested with v6.1.1)
  • WooCommerce (tested with v7.1.0)
  • Advanced Custom Fields PRO
  • Access to your theme’s functions.php file ** warning: we are using this file to provide a basic functional example. If you are a beginner, please familiarise yourself with this file prior to editing. For real-life cases it is recommended that you create a separate plugin. **

Adding the ACF Options page

We first want to register a new ACF Options page. To do this, we just need to add the following code to our themes functions.php file:

// Add ACF options page
if( function_exists('acf_add_options_page') ) {
    acf_add_options_page();
}
PHP

Adding custom fields

Next, we need to create our custom fields and display them on the options page we just created. A new field group should be added called ‘Shipping Options’. The location should be set to show the field group if the options page is equal to ‘Options’.

A new repeater type field called ‘Extra Shipping Prices’ should then be added to this new field group, with an alias / field name of ‘shipping_prices’. This repeater should have three sub-fields added – ‘Tag name’, ‘Fee amount’ and ‘Extra charge message’. All fields should be set as mandatory.

Each subfield should have the following attributes set:

Field Label Alias Type Further Info
Tag name tag_name Taxonomy The taxonomy to be displayed should be set as ‘Tag (product_tag)’, and the return type should be set to ‘Term ID’
Fee amount fee Number
Extra charge message extra_charge_message Text Area

Add code to functions.php

Now we just need to add the new custom function and action into our themes functions.php file. We first need to create our function and its corresponding action:

/******* Calculate custom fees ********/
function action_thewoocommerce_cart_calculate_fees( $cart ) {
    if ( is_admin() && ! defined( 'DOING_AJAX' ) )
        return;

    // Custom code here

}
add_action( 'woocommerce_cart_calculate_fees', 'action_thewoocommerce_cart_calculate_fees', 10, 1 );
PHP

Next, we’ll declare $excluded_shipping_method as ‘local_pickup’. We’ll use this variable later on to ensure that fees are only added if they do not include this shipping method. We’ll then use WC sessions to determine the chosen shipping method:

// Shipping
$excluded_shipping_method = 'local_pickup'; // The excluded shipping method
$chosen_shipping_method_id = WC()->session->get( 'chosen_shipping_methods' )[0];
$chosen_shipping_method    = explode( ':', $chosen_shipping_method_id )[0];
PHP

We now want to initiate a new $settings array, and populate the array with the data from our ‘shipping_prices’ repeater field on our options page:

// Initiate settings array
$settings = array();

// ACF Repeater
if( have_rows('shipping_prices', 'option') ): // Check rows exist
    while( have_rows('shipping_prices', 'option') ) : the_row(); // Loop through rows
        // Populate settings array
        $settings[] = [
            'product_id'    => array( get_sub_field('tag_name') ),
            'amount'        => get_sub_field('fee'),
            'name'          => __( get_sub_field('extra_charge_message'), 'woocommerce' ),
            'total_amount'  => 0,
        ];
    endwhile;
    else :
endif;
PHP

Now we want to loop through the cart contents and settings array and set the total amount depending on the term conditions. We’ll then loop through the settings and, if the total amount is greater than 0 and not using the excluded shipping method, we will add the fee to the cart:

// Loop through cart contents
foreach ( $cart->get_cart_contents() as $cart_item ) {
    // Get product id and quantity
    $product_id = $cart_item['product_id'];
    $quantity = $cart_item['quantity'];
    // Loop trough settings array
    foreach ( $settings as $key => $setting ) {
        // Search for the term ID
         if (has_term( $settings[$key]['product_id'], 'product_tag', $product_id )) {
            // Set total amount
            $settings[$key]['total_amount'] += $setting['amount'] * $quantity;
        }
    }
}

// Loop trough settings array (output)
foreach ( $settings as $setting ) {
    // If greater than 0 and not using excluded shipping method
    if ( $setting['total_amount'] > 0 && $chosen_shipping_method != $excluded_shipping_method) {
        // Add fee
        $cart->add_fee( $setting['name'], $setting['total_amount'], false );
    }
}
PHP

The final custom function should look something like this:

/******* Calculate custom fees ********/
function action_thewoocommerce_cart_calculate_fees( $cart ) {
    if ( is_admin() && ! defined( 'DOING_AJAX' ) )
        return;

    // Shipping
    $excluded_shipping_method = 'local_pickup'; // The excluded shipping method
    $chosen_shipping_method_id = WC()->session->get( 'chosen_shipping_methods' )[0];
    $chosen_shipping_method    = explode( ':', $chosen_shipping_method_id )[0];

    // Initiate settings array
    $settings = array();

    // ACF Repeater
    if( have_rows('shipping_prices', 'option') ): // Check rows exist
        while( have_rows('shipping_prices', 'option') ) : the_row(); // Loop through rows
            // Populate settings array
            $settings[] = [
                'product_id'    => array( get_sub_field('tag_name') ),
                'amount'        => get_sub_field('fee'),
                'name'          => __( get_sub_field('extra_charge_message'), 'woocommerce' ),
                'total_amount'  => 0,
            ];
        endwhile;
        else :
    endif;

    // Loop through cart contents
    foreach ( $cart->get_cart_contents() as $cart_item ) {
        // Get product id and quantity
        $product_id = $cart_item['product_id'];
        $quantity = $cart_item['quantity'];
        // Loop trough settings array
        foreach ( $settings as $key => $setting ) {
            // Search for the term ID
             if (has_term( $settings[$key]['product_id'], 'product_tag', $product_id )) {
                // Set total amount
                $settings[$key]['total_amount'] += $setting['amount'] * $quantity;
            }
        }
    }

    // Loop trough settings array (output)
    foreach ( $settings as $setting ) {
        // If greater than 0 and not using excluded shipping method
        if ( $setting['total_amount'] > 0 && $chosen_shipping_method != $excluded_shipping_method) {
            // Add fee
            $cart->add_fee( $setting['name'], $setting['total_amount'], false );
        }
    }
}
add_action( 'woocommerce_cart_calculate_fees', 'action_thewoocommerce_cart_calculate_fees', 10, 1 );
PHP

Recap

To conclude, this tutorial should have helped you create some extra custom shipping fees based off of taxonomies using WooCommerce, Advanced Custom Fields PRO and some basic theme functions.

/0 Comments/by
0 replies

Leave a Reply

Want to join the discussion?
Feel free to contribute!

Leave a Reply

© Copyright - The Code Onion
How to display attribute descriptions after variation selection on WooCommerce...