Automatically add to cart latest published product on visit in Woocommerce

Question

In WooCommerce, I am currently using a function that auto add to cart a specific product (here product ID 87) on page visit, using this code snippet:

// add item to cart on visit
add_action( 'template_redirect', 'add_product_to_cart' );
function add_product_to_cart() {

    if ( ! is_admin() ) {

        $product_id = 87;
        $found = false;
        //check if product already in cart
        if ( sizeof( WC()->cart->get_cart() ) > 0 ) {
            foreach ( WC()->cart->get_cart() as $cart_item_key => $values ) {
                $_product = $values['data'];
                if ( $_product->id == $product_id )
                    $found = true;
            }
            // if product not found, add it
            if ( ! $found )
                WC()->cart->add_to_cart( $product_id );
        } else {
            // if no products in cart, add it
            WC()->cart->add_to_cart( $product_id );
        }
    }
}

How could I get dynamically the latest product id from woocommerce, in this function, instead of a specific product ID?

Any help or advice will be appreciated.

LoicTheAztec LoicTheAztec · Accepted Answer · 2018-01-20T22:34:39

This is possible easily including a simple very light SQL query in your code snippet that will get the last published product ID.

WC official code snippet is outdated as $product->id has been replaced by $product->get_id().

The completed revisited code:

add_action( 'template_redirect', 'auto_add_to_cart_last_product' );
function auto_add_to_cart_last_product() {
    if ( is_admin() ) return; // Not for admin area

    $cart = WC()->cart;
    global $wpdb;
    $found = false;

    // SQL Query: Get last published product ID
    $result = $wpdb->get_col(" SELECT ID FROM {$wpdb->prefix}posts
    WHERE post_type LIKE 'product'  AND post_status LIKE 'publish' ORDER BY ID DESC LIMIT 1");
    $newest_product_id = reset($result);

    // Check if product already in cart
    if ( ! $cart->is_empty() )
        foreach ( $cart->get_cart() as $cart_item_key => $cart_item ) {
            // Added Woocommerce 3+ compatibility (as $product->id si outdated)
            $product_id = method_exists( $cart_item['data'], 'get_id' ) ? $cart_item['data']->get_id() : $cart_item['data']->id;
            if ( $product_id == $newest_product_id ){
                $found = true; // Found!
                break; // We exit from the loop
            }
        }

    // If product not found or if there is no product in cart, we add it.
    if ( ! $found || $cart->is_empty() )
        $cart->add_to_cart( $product_id );
}

Code goes in function.php file of your active child theme (or active theme).

Tested and works from woocommerce version 2.4 to lastest.

Automatically add to cart latest published product on visit in Woocommerce

1 Answers