* @author Dan Scott
* @copyright 2003-2008 Oy Realnode Ab, Dan Scott
* @license http://www.gnu.org/copyleft/lesser.html LGPL License 2.1
* @version CVS: $Id$
* @link http://pear.php.net/package/File_MARC
*/
// {{{ class File_MARC_List extends Structures_LinkedList_Double
/**
* The File_MARC_List class extends the Structures_LinkedList_Double class
* to override the key() method in a meaningful way for foreach() iterators.
*
* For the list of {@link File_MARC_Field} objects in a {@link File_MARC_Record}
* object, the key() method returns the tag name of the field.
*
* For the list of {@link File_MARC_Subfield} objects in a {@link
* File_MARC_Data_Field} object, the key() method returns the code of
* the subfield.
*
*
* // Iterate through the fields in a record with key=>value iteration
* foreach ($record->getFields() as $tag=>$value) {
* print "$tag: ";
* if ($value instanceof File_MARC_Control_Field) {
* print $value->getData();
* }
* else {
* // Iterate through the subfields in this data field
* foreach ($value->getSubfields() as $code=>$subdata) {
* print "_$code";
* }
* }
* print "\n";
* }
*
*
* @category File_Formats
* @package File_MARC
* @author Dan Scott
* @license http://www.gnu.org/copyleft/lesser.html LGPL License 2.1
* @link http://pear.php.net/package/File_MARC
*/
class File_MARC_List extends Structures_LinkedList_Double
{
// {{{ key()
/**
* Returns the tag for a {@link File_MARC_Field} object, or the code
* for a {@link File_MARC_Subfield} object.
*
* This method enables you to use a foreach iterator to retrieve
* the tag or code as the key for the iterator.
*
* @return string returns the tag or code
*/
function key()
{
if ($this->current() instanceof File_MARC_Field) {
return $this->current()->getTag();
} elseif ($this->current() instanceof File_MARC_Subfield) {
return $this->current()->getCode();
}
return false;
}
// }}}
}
// }}}