How to add filter or hook for "woocommerce_add_to_cart"

Question

I want add to cart two product at the same time, one is original (current) product and second is from drop-down list

add_action('woocommerce_add_to_cart', 'custome_add_to_cart');
$cnt=2
function custome_add_to_cart() {
    global $woocommerce;
      $cnt = $cnt + 1;
      echo $cnt."X";
      echo $p_id=$_POST['assessories'];
    $woocommerce->cart->add_to_cart($p_id, 1);

}

Output:- As you can see in output image below , it adding same drop-down item many time in cart but i want only 1 quantity to add to cart. it seems that add_to_cart function run many times. What should i do or how to add filter with passing second drop-down product as parameter to add to cart function ? so i can add this product also in cart.

Answer 1

This should work:

add_action('woocommerce_add_to_cart', 'custom_add_to_cart');
function custom_add_to_cart() {
    global $woocommerce;

    $product_id = $_POST['assessories'];
    
    $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 );
    }
}

Based on following source: https://docs.woothemes.com/document/automatically-add-product-to-cart-on-visit/

Answer 2

The woocommerce "add_to_cart" functions run the hook "woocommerce_add_to_cart". So, in your code "add_to_cart" is run, which is running "woocommerce_add_to_cart" which runs your code, which runs "add_to_cart", etcetera etcetera... You created a recursive loop.

You need to find an alternative way, or stop calling $woocommerce->cart->add_to_cart($p_id, 1); in your own code.

Answer 3

What you might be looking for is a variable product with some attributes!

Anyway if really you want to do that then you just need the remove_action function :

add_action('woocommerce_add_to_cart', 'custome_add_to_cart');
function custome_add_to_cart() {
    $p_id=$_POST['assessories'];
    remove_action('woocommerce_add_to_cart', __FUNCTION__);
    WC()->cart->add_to_cart( $p_id );
}

This prevents the action from looping indefinitely and is pretty simple.. So it will be added only once for that product. You might want to get the added to cart quantity and give it as a second parameter to the WC()->cart->add_to_cart function so they are both the same quantity

The __FUNCTION__ is a magic PHP tag just giving you the name of the current fucnction as a string, si if the function name is not the same it will still work