Woocommerce Enable/Disable Shipping Methods

cart-shipping.php

<?php
/**
 * Shipping Methods Display
 *
 * In 2.1 we show methods per package. This allows for multiple methods per order if so desired.
 *
 * This template can be overridden by copying it to yourtheme/woocommerce/cart/cart-shipping.php.
 *
 * HOWEVER, on occasion WooCommerce will need to update template files and you
 * (the theme developer) will need to copy the new files to your theme to
 * maintain compatibility. We try to do this as little as possible, but it does
 * happen. When this occurs the version of the template file will be bumped and
 * the readme will list any important changes.
 *
 * @see 	    https://docs.woocommerce.com/document/template-structure/
 * @author 		WooThemes
 * @package 	WooCommerce/Templates
 * @version     3.2.0
 */
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}
?>

<?php
/**
 * Function to determine if the order includes a particular product. If so then Flat_Rate will
 * be the only avialable shipping method for all packages and if not then Flat_Rate will not be a 
 * shipping method for any packages.
 *
 * Filtering woocommerce_package_rates() would be preferable but the array of rates are stored as
 * a session variable AFTER that action so if the cart contents change the aviable shipping methods
 * and rates aren't recalculated.
 */
function has_lamps() {
  $has_lamps = -1;

  // loop through the cart
  $cart = WC() -> cart -> get_cart();

  foreach ( $cart as $cart_key => $cart_values ) {
    $product = $cart_values['product_id'];

    // If cart contains a UPS lamp set a flag.
    if( $product === 779 ) {
      $has_lamps = 1;
    }
  }
  return $has_lamps;
}

/*
 * Use this dump to find out the key for the shipping method you want to disable, like 'flat_rate:7', slug:id.
 */
// echo '<pre>';
// echo 'available_methods:<br/>';
// print_r( $available_methods );
// echo '</pre>';

if ( has_lamps() === 1 ) {

  // If the cart contains lamps then make Flat_Rate the shipping method.
  // Make a new array and populate it with one element.
  $flat_rate = $available_methods[ 'flat_rate:7' ];
  $available_methods = array();
  $available_methods[ 'flat_rate:7' ] = $flat_rate;
} else {

  // If cart does not contain a UPS lamp, disable flat_rate shipping.
  // Convoluted because array_splice seems to require a numeric index.
  $needle = 'flat_rate:7';

  // Get the numeric key for the flat rate shipping method and delete it.
  $rate_keys = array_keys( $available_methods );
  $search_key = array_search( $needle, $rate_keys, false );

  array_splice( $available_methods, $search_key, 1 );
}
?>

<tr class="shipping">
	<th><?php echo wp_kses_post( $package_name ); ?></th>
	<td data-title="<?php echo esc_attr( $package_name ); ?>">
		<?php if ( 1 < count( $available_methods ) ) : ?>
			<ul id="shipping_method">
				<?php foreach ( $available_methods as $method ) : ?>
					<li>
						<?php
							printf( '<input type="radio" name="shipping_method[%1$d]" data-index="%1$d" id="shipping_method_%1$d_%2$s" value="%3$s" class="shipping_method" %4$s />
								<label for="shipping_method_%1$d_%2$s">%5$s</label>',
								$index, sanitize_title( $method->id ), esc_attr( $method->id ), checked( $method->id, $chosen_method, false ), wc_cart_totals_shipping_method_label( $method ) );

							do_action( 'woocommerce_after_shipping_rate', $method, $index );
						?>
					</li>
				<?php endforeach; ?>
			</ul>
		<?php elseif ( 1 === count( $available_methods ) ) :  ?>
			<?php
				$method = current( $available_methods );
				printf( '%3$s <input type="hidden" name="shipping_method[%1$d]" data-index="%1$d" id="shipping_method_%1$d" value="%2$s" class="shipping_method" />', $index, esc_attr( $method->id ), wc_cart_totals_shipping_method_label( $method ) );
				do_action( 'woocommerce_after_shipping_rate', $method, $index );
			?>
		<?php elseif ( WC()->customer->has_calculated_shipping() ) : ?>
			<?php
				if ( is_cart() ) {
					echo apply_filters( 'woocommerce_cart_no_shipping_available_html', wpautop( __( 'There are no shipping methods available. Please ensure that your address has been entered correctly, or contact us if you need any help.', 'woocommerce' ) ) );
				} else {
					echo apply_filters( 'woocommerce_no_shipping_available_html', wpautop( __( 'There are no shipping methods available. Please ensure that your address has been entered correctly, or contact us if you need any help.', 'woocommerce' ) ) );
				}
			?>
		<?php elseif ( ! is_cart() ) : ?>
			<?php echo wpautop( __( 'Enter your full address to see shipping costs.', 'woocommerce' ) ); ?>
		<?php endif; ?>

		<?php if ( $show_package_details ) : ?>
			<?php echo '<p class="woocommerce-shipping-contents"><small>' . esc_html( $package_details ) . '</small></p>'; ?>
		<?php endif; ?>

		<?php if ( ! empty( $show_shipping_calculator ) ) : ?>
			<?php woocommerce_shipping_calculator(); ?>
		<?php endif; ?>
	</td>
</tr>