WordPress WooCommerce: Force local pickup as the only shipping option when products in the cart require it.

woocommerce-force-shipping-pickup.php

<?php
// Force pickup as a shipping option if one or more products in the catalog is marked as pickup only.
// To do this, add a shipping class with the slug 'pickup-only' then set products with that class as required.
// Add this script to your theme's functions.php or similar.

function hideShippingWhenPickupRequired($rates, $package)
{
    foreach ($package['contents'] as $item) {
        $product = $item['data'];
        $shippingClass = $product->get_shipping_class();

        if ('pickup-only' === $shippingClass) {
            // The cart requires pickup
            return array(
               'local_pickup' => $rates['local_pickup'],
            );
        }
    }

    return $rates;
}

add_filter('woocommerce_package_rates', 'hideShippingWhenPickupRequired', 10, 2);

I expanded the above snippets with an extra shipping class for products that are not delivered separately.
Tested with Wordpress 5.7.1 and WooCommerce 5.2.2

/**
 * Hide all other methods if:
 * - At least one item has shipping class 'local-pickup-only'
 *   OR
 * - All items have shipping class 'no-individual-delivery'
**/

function check_local_pickup_only( $rates, $package ) {
    $localPickupOnly = false;
	$noIndividualDelivery = false;
	$regularDelivery = false;
    
    foreach ( WC()->cart->get_cart() as $cart_item_key => $cart_item ) {
		$product = $cart_item['data'];
		$class   = $product->get_shipping_class();
		
		switch ($class) {
			case 'local-pickup-only':
				$localPickupOnly = true;
				break 2;
			case 'no-individual-delivery':
				$noIndividualDelivery = true;
				break;
			default:
				$regularDelivery = true;
				break;
		}
	}
	if ( $noIndividualDelivery && !$regularDelivery ) {$localPickupOnly = true;}
    
	$local = array();
	foreach ( $rates as $rate_id => $rate ) {
		if ('local_pickup' === $rate->method_id ) {
            $local[ $rate_id ] = $rate;
        }
	}
    
    if ( !empty($local) && ($localPickupOnly == true) ) {
        return $local;
    } else {
        return $rates;
    }

}

add_filter( 'woocommerce_package_rates', 'check_local_pickup_only', 10, 2 );

Here's my solution: for carts with one or more products belonging to the shipping class "Local Pickup Only" ($shipping_class_name = 'local-pickup-only'), only the local pickup location(s) (from the Local Pickup in Blocks) will appear.

Tested with WordPress 6.5.2 and WooCommerce 8.7.0.

Important: "Clear customer sessions" after implementation (WooCommerce > Status > Tools > Clear customer sessions).

// WooCommerce display only "Local pickup" location(s) if one or more products added to the cart belong to the shipping class "Local Pickup Only". Dynamically unsets all shipping methods except those with values starting with "pickup_location:" if any product in the cart belongs to the "local-pickup-only" shipping class.

add_filter($hook_name='woocommerce_package_rates', $callback='woocommerce_shipping_method_local_pickup_only', $priority=10, $accepted_args=2);

function woocommerce_shipping_method_local_pickup_only( $rates, $package ) {
   if ( WC() ) {

	   $shipping_class_name = 'local-pickup-only';
	   $in_cart = false;

	   foreach ( WC()->cart->get_cart_contents() as $key => $values ) {
		  if ( $values['data']->get_shipping_class() === $shipping_class_name ) {
			 $in_cart = true;
			 break;
		  }
	   }

	   if ( $in_cart ) {
		  // Unset all shipping methods except for the ones with value starting with "pickup_location:"
		  foreach ( $rates as $rate_key => $rate ) {
			 if ( strpos( $rate_key, 'pickup_location:' ) !== 0 ) {
				unset( $rates[ $rate_key ] );
			 }
		  }
	   }

	   return $rates;

   }
}

Additionally, the snippet below removes the "Calculate shipping" for carts with one or more products belonging to the shipping class "Local Pickup Only" ($shipping_class_name = 'local-pickup-only').

// WooCommerce remove "Calculate shipping" if one or more products added to the cart belong to the shipping class "Local Pickup Only"

add_filter($hook_name='woocommerce_product_needs_shipping', $callback='woocommerce_shipping_method_local_pickup_only_remove_calculate_shipping', $priority=10, $accepted_args=1);

function woocommerce_shipping_method_local_pickup_only_remove_calculate_shipping() {
   if ( WC() ) {

	   $shipping_class_name = 'local-pickup-only';
	   $in_cart = false;
	   $calculate_shipping = true;

	   foreach ( WC()->cart->get_cart_contents() as $key => $values ) {
		  if ( $values['data']->get_shipping_class() === $shipping_class_name ) {
			 $in_cart = true;
			 break;
		  }
	   }

	   if ( $in_cart ) {
		   $calculate_shipping = false;
	   }

	   return $calculate_shipping;

   }
}