Unsetting conditionally custom checkout fields in WooCommerce

Question

In WooCommerce checkout form I have customized the fields. However I don't want display these fields if a product belongs to a specific category. I have that part working.

Next I would like to unset some custom checkout fields, but I can't figure out how or now. Unsetting a normal checkout field is easy and I use for example the following code:

unset( $fields['billing']['billing_company'] );

However for a custom checkout field It doesn't work. Here is how I have set this custom field:

    function company_details_section($checkout)
{
    woocommerce_form_field('delegate_1_name', array(
        'type' => 'text',
        'class' => array(
            'my-field-class form-row-wide delegateExists'
        ) ,
        'label' => __('Full name') ,
    ) , $checkout->get_value('delegate_1_name'));
}

As this belongs to its own section, and not the billing, shipping or normal WooCommerce additional fields, I can't find the way to remove it.

I have tried the following:

unset( $fields['delegate_1_name'] );
unset( $fields['additional']['delegate_1_name'] );
unset( $fields['billing']['delegate_1_name'] );
unset( $fields['shipping']['delegate_1_name'] );
unset( $fields['company_details_section']['delegate_1_name'] );

This is the conditional function that I am using to unset fields:

function wc_ninja_product_is_in_the_cart() {
    // Add your special product IDs here
    $ids = array( '45', '70', '75' );;

    // Products currently in the cart
    $cart_ids = array();

    // Find each product in the cart and add it to the $cart_ids array
    foreach( WC()->cart->get_cart() as $cart_item_key => $values ) {
        $cart_product = $values['data'];
        $cart_ids[]   = $cart_product->id;
    }

    // If one of the special products are in the cart, return true.
    if ( ! empty( array_intersect( $ids, $cart_ids ) ) ) {
        return true;
    } else {
        return false;
    }
}

This is the functional code to unset normal checkout fields:

function wc_ninja_remove_checkout_field( $fields ) {
    if ( ! wc_ninja_product_is_in_the_cart() ) {
        unset( $fields['billing']['billing_company'] );
    }

    return $fields;
}
add_filter( 'woocommerce_checkout_fields' , 'wc_ninja_remove_checkout_field' );

How to unset custom checkout fields in WooCommerce (not classic ones)?

Answer 1

You can't unset a custom checkout field as it's not set in an array like default classic WooCommerce checkout fields.

So you should use your conditional function directly in your custom field creation code. I have also revisited a bit your existing code:

// Conditional function: If one of the special products is in cart return true, else false
function is_in_cart() {
    // Add your special product IDs here
    $ids = array( 45, 70, 75 );

    foreach( WC()->cart->get_cart() as $cart_item ){
        $product_id = version_compare( WC_VERSION, '3.0', '<' ) ? $cart_item['data']->id : $cart_item['data']->get_id();
        if( in_array( $cart_item['data']->get_id(), $ids ) )
            return true;
    }
    return false;
}

add_filter( 'woocommerce_checkout_fields' , 'remove_checkout_fields', 10, 1 );
function remove_checkout_fields( $fields ) {
    if( ! is_in_cart() )
        unset($fields['billing']['billing_company']);

    return $fields;
}

add_action( 'woocommerce_after_order_notes', 'company_details_section', 10, 1 );
function company_details_section( $checkout ){
    // Here your conditional function
    if( is_in_cart() ){

        echo '<div id="my_custom_checkout_field"><h3>' . __('Company Details') . '</h3>';

        woocommerce_form_field( 'delegate_1_name', array(
            'type' => 'text',
            'class' => array( 'my-field-class form-row-wide delegateExists' ),
            'label' => __('Full name') ,
        ) , $checkout->get_value( 'delegate_1_name' ) );

        echo '</div>';
    }
}

Code goes in function.php file of your active child theme (or theme) or also in any plugin file.

Tested and works for all WooCommerce versions since 2.5.x