Add new condition to Table Rate settings page

betrs-add-longest-length-condition.php

/**
 * Add ability to find and compare the longest length item in Table Rate shipping
 * https://codecanyon.net/item/table-rate-shipping-for-woocommerce/3796656?ref=bolderelements
 *
 * Code should be added to theme's functions.php file
 */
function betrs_add_longest_length_cond( $conditions ) {
    // add new option to list
    $conditions['longest_length'] = 'Longest Length';
    
    return $conditions;
}
add_filter( 'betrs_shipping_cost_conditionals', 'betrs_add_longest_length_cond', 10, 1 );

function betrs_add_longest_length_cond_secondary( $conditions ) {
    // add new option to list
    $conditions['greater_than']['conditions'][] = 'longest_length';
    $conditions['less_than']['conditions'][] = 'longest_length';
    $conditions['equal_to']['conditions'][] = 'longest_length';
    
    return $conditions;
}
add_filter( 'betrs_shipping_cost_conditionals_secondary', 'betrs_add_longest_length_cond_secondary', 10, 1 );

function betrs_add_longest_length_calc( $data, $items ) {
    $highest_length = 0;
    
    // determine longest length
    foreach( $items as $key => $values ) {
        $item_length = $values[ 'data' ]->get_length();
        if( $item_length > $highest_length ) {
            $highest_length = $item_length;
        }
    }

    // add the new value to the cart data array
    $data['longest_length'] = $highest_length;

    return $data;
}
add_filter( 'betrs_calculated_totals-per_order', 'betrs_add_longest_length_calc', 10, 2 );

function betrs_determine_condition_longest_length( $return, $cond, $cart_data ) {
    // exit if the custom condition is not a dimensional sum
    if( sanitize_title( $cond['cond_type'] ) != 'longest_length' ) return $return;

    // calculate longest length and init comparison numbers
    $comparison = floatval( $cart_data['longest_length'] );
    $cond_tertiary = floatval( $cond['cond_tertiary'] );

    // determine how to compare the sum to the setting
    switch( sanitize_text_field( $cond['cond_secondary'] ) ) {
        case 'greater_than':
            if( $comparison >= $cond_tertiary )
                return true;
            break;
        case 'less_than':
            if( $comparison <= $cond_tertiary )
                return true;
            break;
        case 'equal_to':
            if( $comparison == $cond_tertiary )
                return true;
            break;
    }

    // return false if the condition is not met
    return $return;

}
add_filter( 'betrs_determine_condition_result', 'betrs_determine_condition_longest_length', 10, 3 );