使用preg_replace_callback时出现问题

Question

i have a problem when i use preg_replace_callback. i have google translator class and i want to translate all matches using it .

the code was .

$code = preg_replace_callback('/_e\(\'(.*?)\'\)/',create_function(
'$matches',
'return $translator->translate($matches);'),
$code);

when i make var dump for the var $code, i found its string"1" !!!

im sure that im using a right way for the class.

Thanks.

Answer 1

The problem here is scope. Something similar to this would work in JavaScript, but JS and PHP handle scope differently. To access $translator from within the anonymous function's scope, you need to declare it as a global.

<?php
$code = preg_replace_callback('/_e\(\'(.*?)\'\)/',
            create_function('$matches',
                'global $translator;'.
                'return $translator->translate($matches);'),
            $code);
?>

If you want to keep the anon as a one-liner, you can use the globals array:

<?php
$code = preg_replace_callback('/_e\(\'(.*?)\'\)/',
            create_function('$matches',
                "return $GLOBALS['translator']->translate($matches);"),
            $code);
?>

If you have PHP 5.3.0 or later, this can be alleviated with closures and use:

<?php
$code = preg_replace_callback('/_e\(\'(.*?)\'\)/',
            function($matches) use ($translator) {
                return $translator->translate($matches);
            }, $code);
?>

This is assuming that $translator was created in the same scope as $code.