Hide Woocommerce Checkout Fields Conditionally and Make Them Not Required - php

Question

I have conditionally unset the billing address fields on the woocommerce checkout page, but when submitting place order, woocommerce displays error:
Please enter an address to continue.
I then tried adding a filter on woocommerce_default_address_fields to make the fields optional - which only seems to work if the fields aren't unset.
// make address fields optional - this works fine without the next filter
add_filter( 'woocommerce_default_address_fields' , 'filter_default_address_fields', 20, 1 );
function filter_default_address_fields( $address_fields ) {
// Only on checkout page
if( ! is_checkout() ) return $address_fields;
// All field keys in this array
$fields = array('country','company','address_1','address_2','city','state','postcode');
// Loop through each address fields (billing and shipping)
foreach( $fields as $key_field )
$address_fields[$key_field]['required'] = false;
return $address_fields;
}
//conditionally unset fields
add_filter( 'woocommerce_checkout_fields' , 'simplify_checkout' );
function simplify_checkout( $fields ) {
$customField = false;
foreach( WC()->cart->get_cart() as $cart_item_key => $cart_item ) {
// Check if cart item has attribute
if ( ! empty ($cart_item['custom_attribute']) ) $registry = true;
}
if( $customField ) {
unset($fields['billing']['billing_company']);
unset($fields['billing']['billing_address_1']);
unset($fields['billing']['billing_address_2']);
unset($fields['billing']['billing_city']);
unset($fields['billing']['billing_postcode']);
unset($fields['billing']['billing_country']);
unset($fields['billing']['billing_state']);
}
return $fields;
}
I'm hoping to still be able to conditionally hide / unset the fields along with a successful checkout submission.

Answer 1

I had this problem with the validation message two days ago. I only sell to one country, so I created following workaround. Maybe if you have fewer countries to sell this could work for you too:
Uncomment/Remove unset($fields['billing']['billing_country']);
Go to WooCommerce -> Settings -> Sell to specific countries and
enter your countries.
Now the validation message is inactive, as the Country field is
mandatory. You can remove it now with CSS.
#billing_country_field {
display: none;
}

Answer 2

Just change the action name and try it:
add_filter( 'woocommerce_checkout_fields' , 'custom_override_checkout_fields' );
add_action( 'woocommerce_after_shop_loop_item_title', 'filter_default_address_fields' );