How to make __() and _e() work in any PHP file of wordpress?

Question

I'd like to have wordpress to do I18N for my javascript. My plan is to have javascript code in php file. For example, one sample.js.php file as below:

function foo()
{
   alert(<?php _e('do something'); ?>);
}

The sample.js.php file is referred as javascript.

<script type='text/javascript'>url-to-myplugin/sample.js.php</script>

However, it seems __() and _e() does't work as they are not defined. How to make the _e() and __() work in my case?

Thanks

---

I found the answer. Below code will do the work.

<?php
    define('WP_USE_THEMES', false);
    require('./wp-blog-header.php');
?>

Answer 1

Have you installed gettext extenssion?

Answer 2

Just include WP configuration file into sample.js.php script:

<?php require_once 'your-path-to/wp-config.php'; ?>

function foo()
{
   alert(<?php _e('do something'); ?>);
}