How to filter translated text in WordPress This example shows how to filter the 'This product has sold out.' text in the WP e-Commerce plugin. If the translation domain is 'wpsc' it will replace the text with 'This product is no longer available.'.

wp-gettext-filter.php

<?php

/**
 * This example shows how to filter the 'This product has sold out.' text.
 * If the translation domain is 'wpsc' it will replace the text with 'This product is no longer available.'.
 */
add_filter( 'gettext', 'my_gettext_filter' );
function my_gettext_filter( $translated_text, $text, $domain ) {
  if ( 'wpsc' == $domain ) {
		switch ( $text ) {
			case 'This product has sold out.' :
				$translated_text = __( 'This product is no longer available.', 'my_domain' );
				break;
		}
	}
	return $translated_text;
}

?>