/**
* @param \File_MARC_Subfield $field
*
* @return SubField
*/
private function convertSubfield(\File_MARC_Subfield $field)
{
$code = $field->getCode();
$data = $field->getData();
return new SubField($code, $data);
}
/**
* Returns an id extracted from the identifier subfield passed in
*
* @param \File_MARC_Subfield $idField MARC field containing id information
* @param string $prefix Prefix to search for in id field
* @param bool $raw Return raw match, or normalize?
*
* @return string|bool ID on success, false on failure
*/
protected function getIdFromLinkingField($idField, $prefix = null, $raw = false)
{
$text = $idField->getData();
if (preg_match('/\\(([^)]+)\\)(.+)/', $text, $matches)) {
// If prefix matches, return ID:
if ($matches[1] == $prefix) {
// Special case -- LCCN should not be stripped:
return $raw ? $matches[2] : trim(str_replace(range('a', 'z'), '', $matches[2]));
}
} else {
if ($prefix == null) {
// If no prefix was given or found, we presume it is a raw bib record
return $text;
}
}
return false;
}
/**
* Prepends subfield to subfield list
*
* Adds a File_MARC_Subfield object to the start of the existing list
* of subfields.
*
* @param File_MARC_Subfield $new_subfield The subfield to add
*
* @return File_MARC_Subfield the new File_MARC_Subfield object
*/
function prependSubfield(File_MARC_Subfield $new_subfield)
{
$pos = 0;
$new_subfield->setPosition($pos);
$this->subfields->shift($new_subfield);
$node = null;
$this->subfields->rewind();
while ($node = $this->subfields->next()) {
$pos++;
$node->setPosition($pos);
}
return $new_subfield;
}