Custom Shortcode

woocommerce_product_custom.php

add_shortcode( 'custom-add-to-cart','custom_woocommerce_product_add_to_cart' );
/**
* Display a single prodcut price + cart button
*
* @access public
* @param array $atts
* @return string
*/
function custom_woocommerce_product_add_to_cart( $atts ) {
   	if (empty($atts)) return;

   	global $wpdb, $woocommerce;

   	if (!isset($atts['style'])) $atts['style'] = 'border:4px solid #ccc; padding: 12px;';

   	if ($atts['id']) :
   		$product_data = get_post( $atts['id'] );
	elseif ($atts['sku']) :
		$product_id = $wpdb->get_var($wpdb->prepare("SELECT post_id FROM $wpdb->postmeta WHERE meta_key='_sku' AND meta_value='%s' LIMIT 1", $atts['sku']));
		$product_data = get_post( $product_id );
	else :
		return;
	endif;

	if ($product_data->post_type=='product') {

		$product = $woocommerce->setup_product_data( $product_data );

		ob_start();
?>
		<p class="product">

		<?php echo $product->get_price_html(); ?>

		<?php woocommerce_template_single_add_to_cart(); ?>

		</p>
<?php

		return ob_get_clean();

	} elseif ($product_data->post_type=='product_variation') {

		$product = new WC_Product( $product_data->post_parent );

		$GLOBALS['product'] = $product;

		$variation = new WC_Product_Variation( $product_data->ID );

		ob_start();
?>
		<p class="product product-variation" style="<?php echo $atts['style']; ?>">

		<?php echo $product->get_price_html(); ?>

<?php

		$link = $product->add_to_cart_url();

		$label = apply_filters('add_to_cart_text', __('Add to cart', 'woocommerce'));

		$link = add_query_arg( 'variation_id', $variation->variation_id, $link );

		foreach ($variation->variation_data as $key => $data) {
			if ($data) $link = add_query_arg( $key, $data, $link );
		}

		printf('<a href="%s" rel="nofollow" data-product_id="%s" class="button add_to_cart_button product_type_%s">%s</a>', esc_url( $link ), $product->id, $product->product_type, $label);

?>

		</p><?php

		return ob_get_clean();

	}
}