OwlCyberSecurity - MANAGER

Edit File: formatting.php

<?php
/**
 * Formatting functions for taking care of proper number formats and such
 *
 * @package     Give
 * @since       1.0
 * @copyright   Copyright (c) 2016, GiveWP
 * @license     https://opensource.org/licenses/gpl-license GNU Public License
 * @subpackage  Functions/Formatting
 */

// Exit if accessed directly.
use Give\Helpers\Utils;

if ( ! defined('ABSPATH')) {
    exit;
}

/**
 * Get Currency Formatting Settings for each donation.
 *
 * @since 1.8.15
 *
 * @param int|string $id_or_currency_code Donation ID or Currency code.
 *
 * @return mixed
 */
function give_get_currency_formatting_settings($id_or_currency_code = null)
{
    $give_options = give_get_settings();
    $setting = [];

if ( ! empty($id_or_currency_code)) {
        $currencies = give_get_currencies('all');

// Set default formatting setting only if currency not set as global currency.
        if (
            is_string($id_or_currency_code) &&
            ! empty($give_options['currency']) &&
            $id_or_currency_code !== $give_options['currency'] &&
            array_key_exists($id_or_currency_code, $currencies)
        ) {
            $setting = $currencies[$id_or_currency_code]['setting'];
        } elseif (is_numeric($id_or_currency_code) && 'give_payment' === get_post_type($id_or_currency_code)) {
            $currency = give_get_meta($id_or_currency_code, '_give_payment_currency', true);

if (
                ! empty($currency) &&
                $give_options['currency'] !== $currency
            ) {
                $setting = $currencies[$currency]['setting'];
            }
        }
    }

if (empty($setting)) {
        // Set thousand separator.
        $thousand_separator = isset($give_options['thousands_separator']) ? $give_options['thousands_separator'] : ',';
        $thousand_separator = empty($thousand_separator) ? ' ' : $thousand_separator;

// Set decimal separator.
        $default_decimal_separators = [
            '.' => ',',
            ',' => '.',
        ];

$default_decimal_separator = in_array($thousand_separator, $default_decimal_separators) ?
            $default_decimal_separators[$thousand_separator] :
            '.';

$decimal_separator = ! empty($give_options['decimal_separator']) ? $give_options['decimal_separator'] : $default_decimal_separator;

$setting = [
            'currency_position' => give_get_option('currency_position', 'before'),
            'thousands_separator' => $thousand_separator,
            'decimal_separator' => $decimal_separator,
            'number_decimals' => give_get_option('number_decimals', 0),
        ];
    }

/**
     * Filter the currency formatting setting.
     *
     * @since 1.8.15
     */
    return apply_filters('give_get_currency_formatting_settings', $setting, $id_or_currency_code);
}

/**
 * Get decimal count
 *
 * @since 1.6
 *
 * @param int|string $id_or_currency_code
 *
 * @return mixed
 */
function give_get_price_decimals($id_or_currency_code = null)
{
    // Set currency on basis of donation id.
    if (empty($id_or_currency_code)) {
        $id_or_currency_code = give_get_currency();
    }

$number_of_decimals = 0;

if ( ! give_is_zero_based_currency($id_or_currency_code)) {
        $setting = give_get_currency_formatting_settings($id_or_currency_code);
        $number_of_decimals = $setting['number_decimals'];
    }

/**
     * Filter the number of decimals
     *
     * @since 1.6
     */
    return apply_filters('give_sanitize_amount_decimals', $number_of_decimals, $id_or_currency_code);
}

/**
 * Get thousand separator
 *
 * @since 1.6
 *
 * @param int|string $id_or_currency_code
 *
 * @return mixed
 */
function give_get_price_thousand_separator($id_or_currency_code = null)
{
    $setting = give_get_currency_formatting_settings($id_or_currency_code);

/**
     * Filter the thousand separator
     *
     * @since 1.6
     */
    return apply_filters('give_get_price_thousand_separator', $setting['thousands_separator'], $id_or_currency_code);
}

/**
 * Get decimal separator
 *
 * @since 1.6
 *
 * @param string $id_or_currency_code
 *
 * @return mixed
 */
function give_get_price_decimal_separator($id_or_currency_code = null)
{
    $setting = give_get_currency_formatting_settings($id_or_currency_code);

/**
     * Filter the thousand separator
     *
     * @since 1.6
     */
    return apply_filters('give_get_price_decimal_separator', $setting['decimal_separator'], $id_or_currency_code);
}

/**
 * Check if amount sanitized
 * Note: only for internal purpose
 *
 * Current this function only check if number is DB sanitize.
 *
 * @since 2.4.5
 *
 * @param string $amount
 *
 * @return bool
 */
function give_is_amount_sanitized($amount)
{
    $is_sanitize = false;

if (false === strpos($amount, '.')) {
        return $is_sanitize;
    }

$number_parts = explode('.', $amount);

// Handle thousand separator as '.'
    // Handle sanitize database values.
    $is_sanitize = (2 === count($number_parts) &&
                    is_numeric($number_parts[0]) &&
                    is_numeric($number_parts[1]) &&
                    in_array(strlen($number_parts[1]), [6, 10]));

return $is_sanitize;
}

/**
 * Sanitize Amount before saving to database
 *
 * @since      1.8.12
 *
 * @param int|float|string $number Expects either a float or a string with a decimal separator only (no thousands)
 * @param array|bool       $args   It accepts 'number_decimals', 'trim_zeros', 'currency'.
 *
 * @return string $amount Newly sanitized amount
 */
function give_sanitize_amount_for_db($number, $args = [])
{
    $args['number_decimals'] = 6;

if (
        (isset($args['currency']) && 'XBT' === $args['currency'])
        || 'XBT' === give_get_currency()
    ) {
        $args['number_decimals'] = 10;
    }

return give_maybe_sanitize_amount($number, $args);
}

/**
 * Sanitize Amount before saving to database
 *
 * @since      1.8.12
 *
 * @param int|float|string $number Expects either a float or a string with a decimal separator only (no thousands)
 * @param array|bool       $args   It accepts 'number_decimals', 'trim_zeros', 'currency'.
 *
 * @return string $amount Newly sanitized amount
 */
function give_maybe_sanitize_amount($number, $args = [])
{
    // Bailout.
    if (empty($number) || ( ! is_numeric($number) && ! is_string($number))) {
        return $number;
    }

$func_args = func_get_args();

// Backward compatibility.
    if (isset($func_args[1]) && (is_bool($func_args[1]) || is_numeric($func_args[1]))) {
        $args = [
            'number_decimals' => $func_args[1],
            'trim_zeros' => isset($func_args[2]) ? $func_args[2] : false,
        ];
    }

$args = wp_parse_args(
        $args,
        [
            'number_decimals' => false,
            'trim_zeros' => false,
            'currency' => give_get_currency(),
        ]
    );

$thousand_separator = give_get_price_thousand_separator($args['currency']);
    $decimal_separator = give_get_price_decimal_separator($args['currency']);
    $number_decimals = is_bool($args['number_decimals']) ?
        give_get_price_decimals($args['currency']) :
        $args['number_decimals'];

// Explode number by . decimal separator.
    $number_parts = explode('.', $number);

// Remove currency symbols from number if any.
    $number = trim(str_replace(give_currency_symbols(true), '', $number));

if (
        // Non formatted number.
        false === strpos($number, $thousand_separator)
        && false === strpos($number, $decimal_separator)
    ) {
        return number_format($number, $number_decimals, '.', '');
    } elseif (
        // Decimal formatted number.
        // If number of decimal place set to non zero and
        // number only contains `.` as separator, precision set to less then or equal to number of decimal
        // then number will be consider as decimal formatted which means number is already sanitized.
        $number_decimals
        && '.' === $thousand_separator
        && false !== strpos($number, $thousand_separator)
        && false === strpos($number, $decimal_separator)
        && 2 === count($number_parts)
        && ($number_decimals >= strlen($number_parts[1]))
    ) {
        return number_format($number, $number_decimals, '.', '');
    }

if (give_is_amount_sanitized($number)) {
        // Sanitize database value.
        return number_format($number, $number_decimals, '.', '');
    } elseif (
        '.' === $thousand_separator &&
        false !== strpos($number, $thousand_separator)
    ) {
        // Fix point thousand separator value.
        $number = str_replace('.', '', $number);
    }

return give_sanitize_amount($number, $args);
}

/**
 * Sanitize Amount
 *
 * Note: Do not this function to sanitize amount instead use give_maybe_sanitize_amount function.
 *
 * Returns a sanitized amount by stripping out thousands separators.
 *
 * @since      1.0
 *
 * @param int|float|string $number Expects either a float or a string with a decimal separator only (no thousands)
 * @param array|bool       $args   It accepts 'number_decimals', 'trim_zeros', 'currency'.
 *
 * @return string $amount Newly sanitized amount
 */
function give_sanitize_amount($number, $args = [])
{
    // Bailout.
    if (empty($number) || ( ! is_numeric($number) && ! is_string($number))) {
        return $number;
    }

// Get function arguments.
    $func_args = func_get_args();

$args = wp_parse_args(
        $args,
        [
            'number_decimals' => false,
            'trim_zeros' => false,
            'currency' => give_get_currency(),
        ]
    );

// Remove slash from amount.
    // If thousand or decimal separator is set to ' then in $_POST or $_GET param we will get an escaped number.
    // To prevent notices and warning remove slash from amount/number.
    $number = wp_unslash($number);

$thousand_separator = give_get_price_thousand_separator($args['currency']);

$locale = localeconv();
    $decimals = [
        give_get_price_decimal_separator($args['currency']),
        $locale['decimal_point'],
        $locale['mon_decimal_point'],
    ];

// Remove locale from string
    if ( ! is_float($number)) {
        $number = str_replace($decimals, '.', $number);
    }

// Remove thousand amount formatting if amount has.
    // This condition use to add backward compatibility to version before 1.6, because before version 1.6 we were saving formatted amount to db.
    // Do not replace thousand separator from price if it is same as decimal separator, because it will be already replace by above code.
    if ( ! in_array($thousand_separator, $decimals) && (false !== strpos($number, $thousand_separator))) {
        $number = str_replace($thousand_separator, '', $number);
    } elseif (in_array($thousand_separator, $decimals)) {
        $number = preg_replace('/\.(?=.*\.)/', '', $number);
    }

// Remove non numeric entity before decimal separator.
    $number = preg_replace('/[^0-9\.]/', '', $number);
    $default_dp = give_get_price_decimals($args['currency']);

// Reset negative amount to zero.
    if (0 > $number) {
        $number = number_format(0, $default_dp, '.');
    }

// If number does not have decimal then add number of decimals to it.
    if (
        false === strpos($number, '.')
        || ($default_dp > strlen(substr($number, strpos($number, '.') + 1)))
    ) {
        $number = number_format($number, $default_dp, '.', '');
    }

// Format number by custom number of decimals.
    if (false !== $args['number_decimals']) {
        $dp = intval(is_bool($args['number_decimals']) ? $default_dp : $args['number_decimals']);
        $dp = apply_filters('give_sanitize_amount_decimals', $dp, $number);
        $number = number_format(floatval($number), $dp, '.', '');
    }

// Trim zeros.
    if ($args['trim_zeros'] && strstr($number, '.')) {
        $number = rtrim(rtrim($number, '0'), '.');
    }

/**
     * Filter the sanitize amount
     *
     * @since 1.0
     */
    return apply_filters('give_sanitize_amount', $number);
}

/**
 * Returns a nicely formatted amount.
 *
 * @since 1.0
 *
 * @param string $amount Price amount to format
 * @param array  $args   Array of arguments.
 *
 * @return string $amount   Newly formatted amount or Price Not Available
 */
function give_format_amount($amount, $args = [])
{
    // Backward compatibility.
    if (is_bool($args)) {
        $args = [
            'decimal' => $args,
        ];
    }

$default_args = [
        'decimal' => true,
        'sanitize' => true,
        'donation_id' => 0,
        'currency' => '',
    ];

$args = wp_parse_args($args, $default_args);

// Set Currency based on donation id, if required.
    if ($args['donation_id'] && empty($args['currency'])) {
        $args['currency'] = give_get_meta($args['donation_id'], '_give_payment_currency', true);
    }

$formatted = 0;
    $currency = ! empty($args['currency']) ? $args['currency'] : give_get_currency($args['donation_id']);
    $thousands_sep = give_get_price_thousand_separator($currency);
    $decimal_sep = give_get_price_decimal_separator($currency);
    $decimals = ! empty($args['decimal']) ? give_get_price_decimals($currency) : 0;

if ( ! empty($amount)) {
        // Sanitize amount before formatting.
        $amount = ! empty($args['sanitize']) ?
            give_maybe_sanitize_amount(
                $amount,
                [
                    'number_decimals' => $decimals,
                    'currency' => $currency,
                ]
            ) :
            number_format($amount, $decimals, '.', '');

switch ($currency) {
            case 'INR':
                $decimal_amount = '';

// Extract decimals from amount
                if (($pos = strpos($amount, '.')) !== false) {
                    if ( ! empty($decimals)) {
                        $decimal_amount = substr(round(substr($amount, $pos), $decimals), 1);
                        $amount = substr($amount, 0, $pos);

if ( ! $decimal_amount) {
                            $decimal_amount = substr("{$decimal_sep}0000000000", 0, ($decimals + 1));
                        } elseif (($decimals + 1) > strlen($decimal_amount)) {
                            $decimal_amount = substr("{$decimal_amount}000000000", 0, ($decimals + 1));
                        }
                    } else {
                        $amount = number_format($amount, $decimals, $decimal_sep, '');
                    }
                }

// Extract last 3 from amount
                $result = substr($amount, -3);
                $amount = substr($amount, 0, -3);

// Apply digits 2 by 2
                while (strlen($amount) > 0) {
                    $result = substr($amount, -2) . $thousands_sep . $result;
                    $amount = substr($amount, 0, -2);
                }

$formatted = $result . $decimal_amount;
                break;

default:
                $formatted = number_format($amount, $decimals, $decimal_sep, $thousands_sep);
        }
    }

/**
     * Filter the formatted amount
     *
     * @since 1.0
     */
    return apply_filters(
        'give_format_amount',
        $formatted,
        $amount,
        $decimals,
        $decimal_sep,
        $thousands_sep,
        $currency,
        $args
    );
}

/**
 * Get human readable amount.
 *
 * Note: This function only support large number formatting from million to trillion
 *
 * @since 1.6
 *
 * @use   give_get_price_thousand_separator Get thousand separator.
 *
 * @param string $amount formatted amount number.
 * @param array  $args   Array of arguments.
 *
 * @return string  formatted amount number with large number names.
 */
function give_human_format_large_amount($amount, $args = [])
{
    // Set default currency;
    if (empty($args['currency'])) {
        $args['currency'] = give_get_currency();
    }

// Get thousand separator.
    $thousands_sep = give_get_price_thousand_separator($args['currency']);

// Sanitize amount for calculation purpose.
    $sanitize_amount = give_maybe_sanitize_amount(
        $amount,
        [
            'currency' => $args['currency'],
        ]
    );

// Bailout.
    if ( ! floatval($sanitize_amount)) {
        return '0';
    };

// Explode amount to calculate name of large numbers.
    $amount_array = explode($thousands_sep, $amount);

// Calculate amount parts count.
    $amount_count_parts = count($amount_array);

// Human format amount (default).
    $human_format_amount = $amount;

switch ($args['currency']) {
        case 'INR':
            // Calculate large number formatted amount.
            if (4 < $amount_count_parts) {
                $human_format_amount = sprintf(
                    esc_html__('%s arab', 'give'),
                    round(($sanitize_amount / 1000000000), 2)
                );
            } elseif (3 < $amount_count_parts) {
                $human_format_amount = sprintf(esc_html__('%s crore', 'give'), round(($sanitize_amount / 10000000), 2));
            } elseif (2 < $amount_count_parts) {
                $human_format_amount = sprintf(esc_html__('%s lakh', 'give'), round(($sanitize_amount / 100000), 2));
            }
            break;
        default:
            // Calculate large number formatted amount.
            if (4 < $amount_count_parts) {
                $human_format_amount = sprintf(
                    esc_html__('%s trillion', 'give'),
                    round(($sanitize_amount / 1000000000000), 2)
                );
            } elseif (3 < $amount_count_parts) {
                $human_format_amount = sprintf(
                    esc_html__('%s billion', 'give'),
                    round(($sanitize_amount / 1000000000), 2)
                );
            } elseif (2 < $amount_count_parts) {
                $human_format_amount = sprintf(
                    esc_html__('%s million', 'give'),
                    round(($sanitize_amount / 1000000), 2)
                );
            }
    }

return apply_filters('give_human_format_large_amount', $human_format_amount, $amount, $sanitize_amount);
}

/**
 * Returns a nicely formatted amount with custom decimal separator.
 *
 * @since 1.0
 *
 * @param array           $args        {
 *
 * @type int|float|string $amount      Formatted or sanitized price. (optional if donation id set)
 * @type int              $donation_id donation amount (optional if set amount, but provide it for better result if formatting decimal amount of donation).
 * @type string           $currency    donation amount (optional if set donation id). Provide either amount or donation id
 * @type int|bool         $dp          number of decimals
 * @type bool             $sanitize    Whether or not sanitize number
 *                                     }
 *
 * @return string $amount Newly formatted amount or Price Not Available
 */
function give_format_decimal($args)
{
    // Backward compatibility.
    if ( ! is_array($args)) {
        $func_args = func_get_args();
        $args = [
            'amount' => $func_args[0],
            'dp' => isset($func_args[1]) ? $func_args[1] : false,
            'sanitize' => isset($func_args[2]) ? $func_args[2] : true,
        ];
    }

$args = wp_parse_args(
        $args,
        [
            'amount' => '',
            'donation_id' => 0,
            'currency' => '',
            'dp' => false,
            'sanitize' => false,
        ]
    );

if ( ! empty($args['donation_id'])) {
        // Set currency if not already done.
        if (empty($args['currency'])) {
            $args['currency'] = give_get_payment_currency_code($args['donation_id']);
        }

// Set amount if not already done.
        if (empty($args['amount'])) {
            $args['amount'] = give_donation_amount($args['donation_id']);
        }
    }

$decimal_separator = give_get_price_decimal_separator();
    $formatted_amount = $args['sanitize'] ?
        give_maybe_sanitize_amount(
            $args['amount'],
            [
                'number_decimals' => $args['dp'],
                'currency' => $args['currency'],
            ]
        ) :
        number_format(
            $args['amount'],
            (is_bool($args['dp']) ? give_get_price_decimals($args['currency']) : $args['dp']),
            '.',
            ''
        );

if (false !== strpos($formatted_amount, '.')) {
        $formatted_amount = str_replace('.', $decimal_separator, $formatted_amount);
    }

return apply_filters('give_format_decimal', $formatted_amount, $args['amount'], $decimal_separator, $args);
}

/**
 * Get date format string on basis of given context.
 *
 * @since 1.7
 *
 * @param string $date_context Date format context name.
 *
 * @return string                  Date format string
 */
function give_date_format($date_context = '')
{
    /**
     * Filter the date context
     *
     * You can add your own date context or use already exist context.
     * For example:
     *    add_filter( 'give_date_format_contexts', 'add_new_date_contexts' );
     *    function add_new_date_contexts( $date_format_contexts ) {
     *        // You can add single context like this $date_format_contexts['checkout'] = 'F j, Y';
     *        // Instead add multiple date context at once.
     *        $new_date_format_contexts = array(
     *            'checkout' => 'F j, Y',
     *            'report'   => 'Y-m-d',
     *            'email'    => 'm/d/Y',
     *        );
     *
     *       // Merge date contexts array only if you are adding multiple date contexts at once otherwise return  $date_format_contexts.
     *       return array_merge( $new_date_format_contexts, $date_format_contexts );
     *
     *    }
     */
    $date_format_contexts = apply_filters('give_date_format_contexts', []);

// Set date format to default date format.
    $date_format = get_option('date_format');

// Update date format if we have non empty date format context array and non empty date format string for that context.
    if ($date_context && ! empty($date_format_contexts) && array_key_exists($date_context, $date_format_contexts)) {
        $date_format = ! empty($date_format_contexts[$date_context])
            ? $date_format_contexts[$date_context]
            : $date_format;
    }

return apply_filters('give_date_format', $date_format);
}

/**
 * Get cache key.
 *
 * @since      1.7
 *
 * @param string $action     Cache key prefix.
 * @param array  $query_args Query array.
 *
 * @return string
 * @deprecated 1.8.7 You can access this function from Give_Cache.
 *
 */
function give_get_cache_key($action, $query_args)
{
    return Give_Cache::get_key($action, $query_args);
}

/**
 * Clean variables using sanitize_text_field. Arrays are cleaned recursively.
 * Non-scalar values are ignored.
 *
 * @since 3.19.3 Don't unserialize data by default and return an empty string when data is serialized and $allow_serialized_data is false
 * @since 3.17.2 Safe unserialize data by default
 * @since  1.8
 *
 * @param string|array $var
 *
 * @return string|array
 */
function give_clean($var, $allow_serialized_data = false)
{
    if (is_array($var)) {
        return array_map('give_clean', $var);
    }

if ( Utils::isSerialized($var)) {
        $var = $allow_serialized_data ? Utils::safeUnserialize($var) : '';
    }

return is_scalar($var) ? sanitize_text_field(wp_unslash($var)) : $var;
}

/**
 * Transforms php.ini notation for numbers (like '2M') to an integer.
 *
 * @since 1.8
 *
 * @param $size
 *
 * @return int
 */
function give_let_to_num($size)
{
    $l = substr($size, -1);
    $ret = substr($size, 0, -1);
    switch (strtoupper($l)) {
        case 'P':
            $ret *= 1024;
        case 'T':
            $ret *= 1024;
        case 'G':
            $ret *= 1024;
        case 'M':
            $ret *= 1024;
        case 'K':
            $ret *= 1024;
    }

return $ret;
}

/**
 * Verify nonce.
 *
 * @since 1.8
 *
 * @param string $nonce       Nonce Hash.
 * @param int    $action      Nonce verification action.
 * @param array  $wp_die_args Nonce fail arguments.
 *
 * @return bool
 */
function give_validate_nonce($nonce, $action = -1, $wp_die_args = [])
{
    // Verify nonce.
    $verify_nonce = wp_verify_nonce($nonce, $action);

// On ajax request send nonce verification status.
    if (wp_doing_ajax()) {
        return $verify_nonce;
    }

if ( ! $verify_nonce) {
        $wp_die_args = wp_parse_args(
            $wp_die_args,
            [
                'message' => __(
                    'We\'re unable to recognize your session. Please refresh the screen to try again; otherwise contact your website administrator for assistance.',
                    'give'
                ),
                'title' => __('Error', 'give'),
                'args' => [
                    'response' => 403,
                ],
            ]
        );

wp_die(
            $wp_die_args['message'],
            $wp_die_args['title'],
            $wp_die_args['args']
        );
    }

return true;
}

/**
 * Verify nonce while processing donation form.
 *
 * @since 2.0
 *
 * @param string $nonce   Nonce value.
 * @param int    $form_id Donation Form ID.
 *
 * @return bool
 */
function give_verify_donation_form_nonce($nonce, $form_id)
{
    // Form nonce action.
    $nonce_action = "give_donation_form_nonce_{$form_id}";

// Nonce validation.
    $verify_nonce = give_validate_nonce($nonce, $nonce_action);

if ( ! $verify_nonce) {
        give_set_error(
            'donation_form_nonce',
            __(
                'We\'re unable to recognize your session. Please refresh the screen to try again; otherwise contact your website administrator for assistance.',
                'give'
            )
        );
    }

return $verify_nonce;
}

/**
 * Check variable and get default or valid value.
 *
 * Helper function to check if a variable is set, empty, etc.
 *
 * @since 1.8
 *
 * @param                   $variable
 * @param string (optional) $conditional    default value: isset
 * @param mixed (optional)  $default        default value: false
 * @param string (optional) $array_key_name default value: false
 *
 * @return mixed
 */
function give_check_variable($variable, $conditional = '', $default = false, $array_key_name = '')
{
    // Get value from array if array key non empty.
    if (empty($array_key_name)) {
        switch ($conditional) {
            case 'isset_empty':
                $variable = (isset($variable) && ! empty($variable)) ? $variable : $default;
                break;

case 'empty':
                $variable = ! empty($variable) ? $variable : $default;
                break;

case 'null':
                $variable = ! is_null($variable) ? $variable : $default;
                break;

default:
                $variable = isset($variable) ? $variable : $default;
        }
    } else {
        $isset = is_array($variable) && array_key_exists($array_key_name, $variable);

switch ($conditional) {
            case 'isset_empty':
                $variable = ($isset && ! empty($variable[$array_key_name])) ? $variable[$array_key_name] : $default;
                break;

case 'empty':
                $variable = ! empty($variable[$array_key_name]) ? $variable[$array_key_name] : $default;
                break;

case 'null':
                $variable = $isset && ! is_null($variable[$array_key_name]) ? $variable[$array_key_name] : $default;
                break;

default:
                $variable = $isset && isset($variable[$array_key_name]) ? $variable[$array_key_name] : $default;
        }
    }

return $variable;
}