PHP simple load, save functions for file to php array with value and charset type conversion

load_save.php

<?php

/**
 * Clear an array of empty values
 *
 * @param  array $keys array keys to explicitly remove regardless
 * @return array the trimmed down array
 */
function array_clear($array, $keys = [])
{
    foreach ($array as $key => $value) {
        if (is_array($value)) {
            do {
                $oldvalue = $value;
                $value    = array_clear($value, $keys);
            }
            while ($oldvalue !== $value);
            $array[$key] = array_clear($value, $keys);
        }

        if (empty($value) && 0 !== $value) {
            unset($array[$key]);
        }

        if (in_array($key, $keys, true)) {
            unset($array[$key]);
        }
    }
    return $array;
}


/**
 * Encode array character encoding recursively
 *
 * @param mixed $data
 * @param string $to_charset convert to encoding
 * @param string $from_charset convert from encoding
 * @return mixed
 */
function to_charset($data, $to_charset = 'UTF-8', $from_charset = 'auto')
{
    if (is_numeric($data)) {
        if (is_float($data)) {
            return (float) $data;
        } else {
            return (int) $data;
        }
    } else if (is_string($data)) {
        return mb_convert_encoding($data, $to_charset, $from_charset);
    } else if (is_array($data)) {
        foreach ($data as $key => $value) {
            $data[$key] = to_charset($value, $to_charset, $from_charset);
        }
    } else if (is_object($data)) {
        foreach ($data as $key => $value) {
            $data->$key = to_charset($value, $to_charset, $from_charset);
        }
    }
    return $data;
}


/**
 * Load a json file and return a php array of the content
 *
 * @param  string $file the json filename
 * @return string|array error string or data array
 */
function json_load($file)
{
    $data = [];
    if (file_exists($file)) {
        $data = to_charset(file_get_contents($file));
        $data = json_decode(
            mb_convert_encoding($data, 'UTF-8', "auto"), true, 512,
            JSON_OBJECT_AS_ARRAY || JSON_BIGINT_AS_STRING
        );
    }
    if (null === $data) {
        return json_last_error_msg();
    }
    if (is_array($data)) {
        $data = to_charset($data);
    }
    return $data;
}


/**
 * Save data array to a json
 *
 * @param  string $file the json filename
 * @param  array $data data to save
 * @param  string optional $prepend string to prepend in the file
 * @param  string optional $append string to append to the file
 * @return boolean true|string TRUE if success or string error message
 */
function json_save($file, $data, $prepend = '', $append = '')
{
    if (empty($data)) {
        return 'No data to write to file.';
    }
    if (is_array($data)) {
        $data = to_charset($data);
    }
    if (!file_put_contents($file,
            $prepend . json_encode($data, JSON_PRETTY_PRINT) . $append)) {
        $error = json_last_error_msg();
        if (empty($error)) {
            $error = sprintf("Unknown Error writing file: '%s' (Prepend: '%s', Append: '%s')",
                $file, $prepend, $append);
        }
        return $error;
    }
    return true;
}


/**
 * Load a serialized php data file and return it
 *
 * @param  string $filename the json filename
 * @return array $data
 */
function serialize_load($file)
{
    if (file_exists($file)) {
        $data = unserialize(file_get_contents($file));
    }
    return empty($data) ? [] : $data;
}


/**
 * Save data array to a php serialized data
 *
 * @param  string $filename the json filename
 * @param  array $data data to save
 * @return boolean result
 */
function serialize_save($file, $data)
{
    if (empty($data)) {
        return 'No data to write to file.';
    }
    return file_put_contents($file, serialize($data));
}