[MarketShip] Set default shipping boxes for Live Rates.

marketship-set-default-boxes.php

<?php

/**
 * Filters the default value for the `shippo_boxes` user meta key.
 *
 * @param mixed  $value    Meta value.
 * @param int    $user_id  User ID.
 * @param string $meta_key Meta key.
 * @param bool   $single   Whether to return a single value.
 *
 * @return array|string
 */
function marketship_filter_default_shippo_boxes( $value, $user_id, $meta_key, $single ) {
    if ( 'shippo_boxes' !== $meta_key ) {
        return $value;
    }

    $default_boxes = array(
        array (
            'name'              => 'Default Box',
            'template'          => 'custom', // Should always be 'custom'.
            'length'            => '4',      // Dimensions are always in store dimension units.
            'width'             => '4',
            'height'            => '4',
            'weight'            => '4',      // Weight of empty box.
            'weight_unit'       => 'oz',     // Can be 'g', 'oz', 'lb', or 'kg'.
            'weight_limit'      => '240',    // Max box weight.
            'weight_limit_unit' => 'oz',
        ),
    );

    return $single ? $default_boxes : array( $default_boxes );
}

add_filter( 'default_user_metadata', 'marketship_filter_default_shippo_boxes', 10, 4 );