How to save a JSON as unescaped UTF-8 in PHP 5.3?

Question

I created a JSON file:

$json = array(
    "Sample" =>array(
        "context" => $context,
        "date"    => $date
    )
);

$url= "sample.json";
$myfile = fopen($url, "w") or die("Unable to open file!");
fwrite($myfile, json_encode($json));    
fclose($myfile);

I need to save it as UTF-8 and I can't use JSON_UNESCAPED_UNICODE in PHP 5.3. So what should I do now?

Answer 1

If you can't use JSON_UNESCAPED_UNICODE, you could probably unescape the JSON yourself after it's been encoded:

$json = array(
    'Sample' => array(
        'context' => 'جمهوری اسلامی ایران'
    )
);

$encoded = json_encode($json);
var_dump($encoded); // context: "\u062c\u0645..."

$unescaped = preg_replace_callback('/\\\\u(\w{4})/', function ($matches) {
    return html_entity_decode('&#x' . $matches[1] . ';', ENT_COMPAT, 'UTF-8');
}, $encoded);

var_dump($unescaped); // context is unescaped
file_put_contents('sample.json', $unescaped);

Here's an example in PHP5.3.

However, this shouldn't be necessary, as any JSON parser should correctly parse the escaped Unicode characters and give you back your original string.

EDIT: A better pattern to use might be /(?<!\\\\)\\\\u(\w{4})/, which avoids incorrectly unescaping a JSON sequence like "\\u1234". See an example.

Answer 2

Perfect Implemention

• Compatible with \\ (escaped backslashes itself)
• Compatible with JSON_HEX_* flags

 

function raw_json_encode($input, $flags = 0) {
    $fails = implode('|', array_filter(array(
        '\\\\',
        $flags & JSON_HEX_TAG ? 'u003[CE]' : '',
        $flags & JSON_HEX_AMP ? 'u0026' : '',
        $flags & JSON_HEX_APOS ? 'u0027' : '',
        $flags & JSON_HEX_QUOT ? 'u0022' : '',
    )));
    $pattern = "/\\\\(?:(?:$fails)(*SKIP)(*FAIL)|u([0-9a-fA-F]{4}))/";
    $callback = function ($m) {
        return html_entity_decode("&#x$m[1];", ENT_QUOTES, 'UTF-8');
    };
    return preg_replace_callback($pattern, $callback, json_encode($input, $flags));
}

Example

<?php
$json = array(
    'Sample' => array(
        'specialchars' => '<x>& \' "</x>',
        'backslashes' => '\\u0020',
        'context' => 'جمهوری اسلامی ایران',
    )
);

echo raw_json_encode($json, JSON_HEX_TAG | JSON_HEX_AMP | JSON_HEX_APOS | JSON_HEX_QUOT);

/* 
{"Sample":{"specialchars":"\u003Cx\u003E\u0026 \u0027 \u0022\u003C\/x\u003E","backslashes":"\\u0020","context":"جمهوری اسلامی ایران"}}
*/