WooCommerce Conditional Upsells

woocommerce-conditional-upsells.php

<?php

/*
	Plugin Name: WooCommerce Conditional Upsells
	Plugin URI: http://www.ultimatewoo.com/woocommerce-conditional-upsells
	Description: This is a fork of another Gist that we have put into plugin format. Define a list of Upsell products and a list of Required products. Upsells will be shown as an option to add to cart when all required products are currently in cart. They'll also be removed when a required product is removed.
	Version: 1.0
	Author: UltimateWoo
	Author URI: http://www.ultimatewoo.com/
	
	Source: https://gist.github.com/EngageWP/9a3e30d9dc164ebce458
*/

/*
 * Replace the following ID lists with your own
 * Keep the IDs comma separated and within the single quotes
 *
 * REQUIRED_PRODUCT_IDS takes IDs of the products required to be in the cart
 * before the Upsells can be added
 *
 * UPSELL_PRODUCT_IDS takes IDs of the products considered to be Upsells
 */
define( 'REQUIRED_PRODUCT_IDS', '70, 37, 53, 19' );
define( 'UPSELL_PRODUCT_IDS', '73, 50' );

class WC_Conditional_Upsells {

	private $required;
	private $required_items_count;
	private $upsells;
	private $upsells_count;
	private $cart;
	private $message;

	public function __construct() {

		$this->cart = array(); // Cart contents

		$this->required = explode( ',', trim( REQUIRED_PRODUCT_IDS ) ); // Products required to purchase upsell(s)
		$this->upsells = explode( ',', trim( UPSELL_PRODUCT_IDS ) ); // Upsell(s) that can be purchased when all required products are in cart

		$this->required_items_count = count( $this->required ); // Number of required products
		$this->upsells_count = count( $this->upsells ); // Number of upsell products

		add_action( 'init', array( $this, 'list_cart_items' ) );

		add_action( 'template_redirect', array( $this, 'empty_cart' ) );

		add_action( 'woocommerce_before_cart', array( $this, 'show_upsell' ) );

	}

	/*
	 * Stores the cart items
	 */

	public function list_cart_items() {

		global $woocommerce;

		$in_cart = $woocommerce->cart->get_cart();

		foreach ( $in_cart as $cart_item ) {

			$cart_items[] = array(

				'id' => $cart_item['product_id'],
				'qty' => $cart_item['quantity']

			);

		}

		if ( !empty( $cart_items ) )
			$this->cart = $cart_items;

	}

	/*
	 * Show add-to-cart links for each Upsell NOT in the cart
	 * Displays upsells only when all requierd items are in cart
	 */

	public function show_upsell() {

		global $woocommerce;

		$upsells = $this->upsells;

		$cart_items = $this->cart;

		$add_to_cart_url = trailingslashit( $woocommerce->cart->get_cart_url() ) . '?add-to-cart=';

		$running_count = 0;

		$required = $this->required;

		//* Assemble cart product IDs into a simple array
		foreach ( $cart_items as $key => $value ) {

			$current_ids[] = $value['id'];

		}

		foreach ( $required as $id ) {

			if ( in_array( $id, $current_ids ) ) {

				$running_count++;

			}

		}

		//* If all the required items are in the cart and there are upsells
		if ( $running_count == $this->required_items_count && !empty( $upsells ) ) {

			echo '<div class="upsell">';

			echo '<ul>';

			foreach ( $upsells as $upsell ) {

				if ( !in_array( $upsell, $current_ids ) ) {

					echo '<li><a href="' . $add_to_cart_url . $upsell . '">Add ' . get_the_title( $upsell ) . ' to cart</a></li>';

				}

			}

			echo '</ul>';

			echo '</div>';

		}

	}

	/*
	 * If all the required items are NOT in the cart and there are upsells in the cart
	 * then empty the cart and re-add the items minus the required item that was removed and the upsell(s)
	 */

	public function empty_cart() {

		global $woocommerce;

		$upsells = $this->upsells;

		$cart_items = $this->cart;

		$required = $this->required;

		//* Count to see if required products are in cart
		$required_items_in_cart = 0;

		//* Count to see if upsells are in cart
		$upsells_in_cart = 0;

		//* Assemble cart product IDs into a simple array
		foreach ( $cart_items as $key => $value ) {

			$current_ids[] = $value['id'];

		}

		foreach ( $required as $id ) {

			if ( !empty( $current_ids ) && in_array( $id, $current_ids ) ) {

				$required_items_in_cart++;

			}

		}

		foreach ( $upsells as $upsell ) {

			if ( !empty( $current_ids ) && in_array( $upsell, $current_ids ) ) {

				$upsells_in_cart++;

			}

		}


		if ( ( $required_items_in_cart < $this->required_items_count ) && $upsells_in_cart > 0 ) {

			//* Get a fresh copy of the cart
			$in_cart = $woocommerce->cart->get_cart();

			foreach ( $in_cart as $cart_item ) {

				$current_ids_refreshed[] = array(

					'id' => $cart_item['product_id'],
					'qty' => $cart_item['quantity']

				);

			}

			//* Reset $cart_items to store the fresh cart array
			$cart_items = $current_ids_refreshed;

			//* Empty the cart
			$woocommerce->cart->empty_cart();

			//* Loop through the new $cart_items
			foreach ( $cart_items as $cart_item ) {

				$id = $cart_item['id']; // ID of each item in cart
				$qty = $cart_item['qty']; // Quantity of each item in cart

				// re-add items the items that are not upsells
				if ( !in_array( $id, $upsells ) ) {

					$woocommerce->cart->add_to_cart( $id, $qty );

				} else {

					$not_readded[] = $id;

				}

			}

			$list_items = '';

			foreach ( $not_readded as $key => $value ) {

				$list_items .= '<li><a href="' . get_permalink( $value ) . '">' . get_the_title( $value ) . '</a></li>';

			}

			$message = '<p>The following items were removed from your cart because they are not available based on your cart\'s contents:</p>';

			$message .= '<ul>' . $list_items . '</ul>';

			$this->message = $message;

			if ( !empty( $not_readded ) ) {

				add_action( 'woocommerce_before_cart', array( $this, 'rv_wc_print_notices' ) );

			}

		}

	}

	public function rv_wc_print_notices() {

		wc_print_notice( $this->message, 'notice' );

	}

}

if ( !is_admin() )
	new WC_Conditional_Upsells;