setVar($key,$value)This method matches i18n:name calls. It builds an interpolation context for later translate calls.
<?php
require_once 'PHPTAL/TranslationService.php';
class MyTranslator implements PHPTAL_TranslationService {
    …
    public function setVar($key, $value){
        $this->_context[$key] = $value;
    }
    …
    private $_context = array();
}
?>