Give_Donate_Form::is_multi_type_donation_form PHP Method

    public function is_multi_type_donation_form()
    {
        $form_type = $this->get_type();
        return 'multi' === $form_type ? true : false;
    }

/**
 * Auto set correct donation level id on basis of amount.
 *
 * Note: If amount does not match to donation level amount then level id will be auto select to first match level id on basis of amount.
 *
 * @param array $valid_data
 * @param array $data
 *
 * @return bool
 */
function give_validate_multi_donation_form_level($valid_data, $data)
{
    /* @var Give_Donate_Form $form*/
    $form = new Give_Donate_Form($data['give-form-id']);
    $donation_level_matched = false;
    if ($form->is_multi_type_donation_form()) {
        // Bailout.
        if (!($variable_prices = $form->get_prices())) {
            return false;
        }
        // Sanitize donation amount.
        $data['give-amount'] = give_sanitize_amount($data['give-amount']);
        // Get number of decimals.
        $default_decimals = give_get_price_decimals();
        if ($data['give-amount'] === give_sanitize_amount(give_get_price_option_amount($data['give-form-id'], $data['give-price-id']), $default_decimals)) {
            return true;
        }
        // Find correct donation level from all donation levels.
        foreach ($variable_prices as $variable_price) {
            // Sanitize level amount.
            $variable_price['_give_amount'] = give_sanitize_amount($variable_price['_give_amount'], $default_decimals);
            // Set first match donation level ID.
            if ($data['give-amount'] === $variable_price['_give_amount']) {
                $_POST['give-price-id'] = $variable_price['_give_id']['level_id'];
                $donation_level_matched = true;
                break;
            }
        }
        // If donation amount is not find in donation levels then check if form has custom donation feature enable or not.
        // If yes then set price id to custom if amount is greater then custom minimum amount (if any).
        if (!$donation_level_matched && 'yes' === get_post_meta($data['give-form-id'], '_give_custom_amount', true)) {
            // Sanitize custom minimum amount.
            $custom_minimum_amount = give_sanitize_amount(get_post_meta($data['give-form-id'], '_give_custom_amount_minimum', true), $default_decimals);
            if ($data['give-amount'] >= $custom_minimum_amount) {
                $_POST['give-price-id'] = 'custom';
                $donation_level_matched = true;
            }
        }
    }
    return $donation_level_matched ? true : false;
}