wc-add-to-cart-form-shortcode.php

<?php
/**
 * Plugin Name: Add to Cart Form Shortcode for WooCommerce
 * Plugin URI: https://github.com/helgatheviking/add-to-cart-form-shortcode
 * Description: Add [add_to_cart_form] shortcode that display a single product add to cart form.
 * Version: 3.1.0
 * Author: helgatheviking
 * Author URI: https://kathyisawesome.com
 * Requires at least: 4.8
 * Tested up to: 5.9.0
 * WC requires at least: 3.2.0
 * WC tested up to: 6.5.0
 * License: GNU General Public License v3.0
 * License URI: http://www.gnu.org/licenses/gpl-3.0.html
 *
 * @package Add to Cart Form Shortcode for WooCommerce
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit; // Exit if accessed directly.
}

if ( ! function_exists( 'kia_add_to_cart_form_features_compatibility' ) ) {

	/**
	 * Declare WooCommerce Features compatibility.
	 *
	 * @since 3.1.0
	 */
	function kia_add_to_cart_form_features_compatibility() {

		if ( ! class_exists( 'Automattic\WooCommerce\Utilities\FeaturesUtil' ) ) {
			return;
		}

		// High Performance Order Storage (HPOS) Compatibility
		\Automattic\WooCommerce\Utilities\FeaturesUtil::declare_compatibility( 'custom_order_tables', plugin_basename( __FILE__ ), true );

		// Cart/Checkout Blocks compatibility.
		\Automattic\WooCommerce\Utilities\FeaturesUtil::declare_compatibility( 'cart_checkout_blocks', plugin_basename( __FILE__ ), true );
	}

}
add_action( 'before_woocommerce_init', 'kia_add_to_cart_form_features_compatibility' );


if ( ! function_exists( 'kia_add_to_cart_form_shortcode' ) ) {
	/**
	 * Display a single product with single-product/add-to-cart/$product_type.php template.
	 *
	 * @param array $atts Attributes.
	 * @return string
	 */
	function kia_add_to_cart_form_shortcode( $atts ) {

		if ( empty( $atts ) ) {
			return '';
		}

		if ( ! isset( $atts['id'] ) && ! isset( $atts['sku'] ) ) {
			return '';
		}

		$atts = shortcode_atts(
			array(
				'id'                => '',
				'sku'               => '',
				'status'            => 'publish',
				'show_price'        => 'true',
				'hide_quantity'     => 'false',
				'allow_form_action' =>  'false',
			),
			$atts,
			'product_add_to_cart_form'
		);

		$query_args = array(
			'posts_per_page'      => 1,
			'post_type'           => 'product',
			'post_status'         => $atts['status'],
			'ignore_sticky_posts' => 1,
			'no_found_rows'       => 1,
		);

		if ( ! empty( $atts['sku'] ) ) {
			$query_args['meta_query'][] = array(
				'key'     => '_sku',
				'value'   => sanitize_text_field( $atts['sku'] ),
				'compare' => '=',
			);

			$query_args['post_type'] = array( 'product', 'product_variation' );
		}

		if ( ! empty( $atts['id'] ) ) {
			$query_args['p'] = absint( $atts['id'] );
		}

		// Hide quantity input if desired.
		if ( 'true' === $atts['hide_quantity'] ) {
			add_filter( 'woocommerce_quantity_input_min', 'kia_add_to_cart_form_return_one' );
			add_filter( 'woocommerce_quantity_input_max', 'kia_add_to_cart_form_return_one' );
		}

		// Change form action to avoid redirect.
		if ( 'false' === $atts[ 'allow_form_action' ] ) {
			add_filter( 'woocommerce_add_to_cart_form_action', '__return_empty_string' );
		}	

		$single_product = new WP_Query( $query_args );

		$preselected_id = '0';

		// Check if sku is a variation.
		if ( ! empty( $atts['sku'] ) && $single_product->have_posts() && 'product_variation' === $single_product->post->post_type ) {

			$variation  = new WC_Product_Variation( $single_product->post->ID );
			$attributes = $variation->get_attributes();

			// Set preselected id to be used by JS to provide context.
			$preselected_id = $single_product->post->ID;

			// Get the parent product object.
			$query_args = array(
				'posts_per_page'      => 1,
				'post_type'           => 'product',
				'post_status'         => 'publish',
				'ignore_sticky_posts' => 1,
				'no_found_rows'       => 1,
				'p'                   => $single_product->post->post_parent,
			);

			$single_product = new WP_Query( $query_args );
			?>
			<script type="text/javascript">
				jQuery( document ).ready( function( $ ) {
					var $variations_form = $( '[data-product-page-preselected-id="<?php echo esc_attr( $preselected_id ); ?>"]' ).find( 'form.variations_form' );

					<?php foreach ( $attributes as $attr => $value ) { ?>
						$variations_form.find( 'select[name="<?php echo esc_attr( $attr ); ?>"]' ).val( '<?php echo esc_js( $value ); ?>' );
					<?php } ?>
				});
			</script>
			<?php
		}

		// For "is_single" to always make load comments_template() for reviews.
		$single_product->is_single = true;

		ob_start();

		global $wp_query, $previous_wp_query;

		// Backup query object so following loops think this is a product page.
		$previous_wp_query = $wp_query;
		// @codingStandardsIgnoreStart
		$wp_query          = $single_product;
		// @codingStandardsIgnoreEnd

		wp_enqueue_script( 'wc-single-product' );

		while ( $single_product->have_posts() ) {
			$single_product->the_post();

			?>
			<div class="product single-product add_to_cart_form_shortcode" data-product-page-preselected-id="<?php echo esc_attr( $preselected_id ); ?>">

				<?php
				if ( wc_string_to_bool( $atts['show_price'] ) ) {
					woocommerce_template_single_price();
				}
				?>

				<?php woocommerce_template_single_add_to_cart(); ?>
			</div>
			<?php
		}

		// Restore $previous_wp_query and reset post data.
		// @codingStandardsIgnoreStart
		$wp_query = $previous_wp_query;
		$previous_wp_query = null;
		// @codingStandardsIgnoreEnd
		wp_reset_postdata();

		// Remove filters.
		if ( 'true' === $atts['hide_quantity'] ) {
			remove_filter( 'woocommerce_quantity_input_min', 'kia_add_to_cart_form_return_one' );
			remove_filter( 'woocommerce_quantity_input_max', 'kia_add_to_cart_form_return_one' );
		}

		if ( 'false' === $atts[ 'allow_form_action' ] ) {
			remove_filter( 'woocommerce_add_to_cart_form_action', '__return_empty_string' );
		}	

		return '<div class="woocommerce">' . ob_get_clean() . '</div>';
	}
}
add_shortcode( 'add_to_cart_form', 'kia_add_to_cart_form_shortcode' );

if ( ! function_exists( 'kia_add_to_cart_form_redirect' ) ) {
	/**
	 * Redirect to same page
	 *
	 * @return string
	 */
	function kia_add_to_cart_form_redirect( $url ) {
		return get_permalink();
	}
}



if ( ! function_exists( 'kia_add_to_cart_form_return_one' ) ) {
	/**
	 * Return integer
	 *
	 * @return int
	 */
	function kia_add_to_cart_form_return_one() {
		return 1;
	}
}