How to get default variation ID (woocommerce)

Question

I need to create an additional "Add to Cart" button on the product page. In a simple product there is no problem with this. It is more difficult in a product with variants. To create such a button I need to know the ID of the default variant.

$product->get_default_attributes();

returns only the attribute name and value, no ID.

How to get the ID of the default variant in php code?

Answer 1

<?php

/**
 * Get default product variation
 *
 * note: this method check for exact match.
 *
 * @param mixed  $product_id WC_Product|WP_Post|int|bool $product Product instance, post instance, numeric or false to use global $post.
 * @param string $return Optional. The format to return the results in. Can be 'id' to return id of variation or 'object' for the product variation object. Default 'id'.
 *
 * @return int|WC_Product_Variation return 0 if not found.
 */
function wc_get_default_variation( $product_id = false, $return = 'id' ) {
    // do not use wc_get_product() to bypass some limits
    $product = WC()->product_factory->get_product( $product_id );

    if ( empty( $product ) || ! $product instanceof WC_Product_Variable ) {
        return 0;
    }

    if ( $product->has_child() ) {
        $attributes = $product->get_default_attributes();

        if ( ! empty( $attributes ) ) {
            $check_count      = true;
            $attributes_count = count( $attributes );

            // get in-stock (if enabled in wc options) and visible variations
            $variations = $product->get_available_variations( 'objects' );

            foreach ( $variations as $variation ) {
                $variation_attributes = $variation->get_attributes();

                // check count for first time
                // if not match, it means that user do not set default value for some variation attrs
                if ( $check_count && $attributes_count !== count( $variation_attributes ) ) {
                    break;
                }

                // no need to check count anymore
                $check_count = false;

                // remove 'any' attrs (empty values)
                $variation_attributes = array_filter( $variation_attributes );

                // add 'any' attrs with default value
                $variation_attributes = wp_parse_args( $variation_attributes, $attributes );

                // check is default
                if ( $variation_attributes == $attributes ) {
                    if ( $return === 'id' ) {
                        return $variation->get_id();
                    }

                    return $variation;
                }
            }
        }
    }

    return 0;
}

---

https://gist.github.com/AkramiPro/c8ddb83d253714730ac26d3a64e7941e

Answer 2

Try this code

add_filter('woocommerce_variable_price_html', 'custom_variation_price', 10, 2);
function custom_variation_price( $price, $product ) {
    $available_variations = $product->get_available_variations();
    $selectedPrice = '';
    $dump = '';

    foreach ( $available_variations as $variation )
    {
        // $dump = $dump . '<pre>' . var_export($variation['attributes'], true) . '</pre>';

        $isDefVariation=false;
        foreach($product->get_default_attributes() as $key=>$val){
            // $dump = $dump . '<pre>' . var_export($key, true) . '</pre>';
            // $dump = $dump . '<pre>' . var_export($val, true) . '</pre>';
            if($variation['attributes']['attribute_'.$key]==$val){
                $isDefVariation=true;
            }   
        }
        if($isDefVariation){
            $price = $variation['display_price'];         
        }
    }
    $selectedPrice = wc_price($price);

//  $dump = $dump . '<pre>' . var_export($available_variations, true) . '</pre>';

    return $selectedPrice . $dump;
}