<?php
// $Id$
abstract class XMLDatastream {
static $XMLNS = 'http://www.islandora.ca';
static $errors = NULL;
protected $xml = NULL;
private $valid = NULL;
protected $forceSchema = FALSE; // if set, the datastream will be validated against the specified schema in self::$SCHEMA_URI instead of
// reading the schema URI from the datastream.
public $pid;
public $dsid;
/**
* Parses an PID from an identifier.
* @param string $identifier
* @return string $pid
*/
public static function getPidFromIdentifier($identifier) {
return substr($identifier, 0, strpos($identifier, "/"));
}
/**
* validPid
* Validates a fedora PID based on the regexp provided in the fedora
* 3.3 documentation.
* http://www.fedora-commons.org/confluence/display/FCR30/Fedora+Identifiers
*
* @param String $pid
* @return boolean $valid
*/
public static function validPid($pid) {
$valid = FALSE;
if (strlen(trim($pid)) < = 64 & & preg_match('/^([A-Za-z0-9]|-|\.)+:(([A-Za-z0-9])|-|\.|~|_|(%[0-9A-F]{2}))+$/', trim($pid))) {
$valid = TRUE;
}
return $valid;
}
/**
* validDsid
* Validates a fedora Dsid based on the the allowed XML standard NCName.
* The regexp is a "regular" subset of names allowed, it excludes some extended hex characters that are
* technically permitted.
* http://www.fedora-commons.org/confluence/display/FCR30/Fedora+Identifiers
*
* @param String $pid
* @return boolean $valid
*/
public static function validDsid($dsid) {
$valid = FALSE;
if (strlen(trim($dsid)) < = 64 & & preg_match('/^[a-zA-Z0-9\_\-\.]+$/', trim($dsid))) {
$valid = TRUE;
}
return $valid;
}
/**
* Parses the DSID from an identifier.
* TODO: combine this method with getPidFromIdentifier?
* @param string $identifier
* @return string $dsid
*/
public static function getDSIDFromIdentifier($identifier) {
$temp = strstr($identifier, "/");
return substr($temp, 1);
}
/**
* Constructs an XMLDatastream object from the XML file specified.
* Returns FALSE on failure.
*
* @param string $filename
* @return XMLDatastream $cm
*/
public static function loadFromFile($filename) {
return new self(file_get_contents($filename));
}
/**
* Constructor
* NOTE: Use the static constructor methods whenever possible.
*
* @param string $xmlStr
* @param string $pid
* @param string $dsid
* @return XMLDatastream $cm
*/
public function __construct($xmlStr, $pid = NULL, $dsid = NULL) {
libxml_use_internal_errors(true);
$this->pid=$pid;
$this->dsid=$dsid;
if ($xmlStr !== NULL) {
$this->xml = (is_object($xmlStr) & & get_class($xmlStr) == DOMDocument)?$xmlStr : DOMDocument::loadXML($xmlStr);
}
}
/**
* Gets the identifier for this XMLDatastream
* Returns FALSE on failure.
*
* NOTE: not available if constructed directly from file.
*
* @return string identifier
*/
public function getIdentifier() {
return ($this->pid != NULL & & $this->dsid != NULL) ? $this->pid . '/'. $this->dsid : FALSE;
}
/**
* Dumps the XMLDatastream as an XML String
*
*
* @return string xml
*/
public function dumpXml() {
if ($this->xml == NULL) {
$this->fetchXml();
}
return $this->xml->saveXml();
}
/**
* Validates the XMLDatastream against the schema location
* defined by the xmlns:schemaLocation attribute of the root
* element. If the xmlns:schemaLocation attribute does not exist,
* then it is assumed to be the old schema and it attempts to convert
* using the convertFromOldSchema method.
*
* TODO: Maybe change it so that it always validates against a known
* schema. This makes more sense because this class assumes the structure
* to be known after it has been validated.
*
* @return boolean $valid
*/
public function validate() {
if ($this->valid === NULL) {
$ret = TRUE;
if ($this->xml == NULL) {
$this->fetchXml();
}
// figure out if we're dealing with a new or old schema
$rootEl = $this->xml->firstChild;
if (!$rootEl->hasAttributes() || $rootEl->attributes->getNamedItem('schemaLocation') === NULL ) {
//$tmpname = substr($this->pid, strpos($this->pid, ':') + 1);
$tmpname = user_password(10);
$this->convertFromOldSchema();
drupal_add_js("fedora_repository_print_new_schema_$tmpname = function(tagID) {
var target = document.getElementById(tagID);
var content = target.innerHTML;
var text = '< html > < head > < title > Title' +
'< / title > < body > ' + content +'< / body > < / html > ';
printerWindow = window.open('', '', 'toolbar=no,location=no,' + 'status=no,menu=no,scrollbars=yes,width=650,height=400');
printerWindow.document.open();
printerWindow.document.write(text);
} ", 'inline');
drupal_set_message('< span id = "new_schema_'. $tmpname .'" style = "display: none;" > '. htmlentities($this->xml->saveXML()) .'< / span > Warning: XMLDatastream performed conversion of \''. $this->getIdentifier() .'\' from old schema. Please update the datastream. The new datastream contents are < a href = "javascript:fedora_repository_print_new_schema_'. $tmpname .'(\'new_schema_'. $tmpname .'\')" > here.< / a > ');
$rootEl = $this->xml->firstChild;
}
$schemaLocation = NULL;
if ($this->forceSchema) {
// hack because you cant easily get the static property value from
// a subclass.
$vars = get_class_vars(get_class($this));
$schemaLocation = $vars['SCHEMA_URI'];
}
elseif ($rootEl->attributes->getNamedItem('schemaLocation') !== NULL) {
//figure out where the schema is located and validate.
list(, $schemaLocation) = preg_split('/\s+/', $rootEl->attributes->getNamedItem('schemaLocation')->nodeValue);
$name = $rootEl->getAttribute('name');
if ($name !== FALSE) {
$this->name = $name;
}
}
$schemaLocation = NULL;
return TRUE;
if ($schemaLocation !== NULL) {
if (!$this->xml->schemaValidate($schemaLocation)) {
$ret = FALSE;
$errors=libxml_get_errors();
foreach ($errors as $err) {
self::$errors[] = 'XML Error: Line '. $err->line .': '. $err->message;
}
}
else {
$this->name=$rootEl->attributes->getNamedItem('name')->nodeValue;
}
}
else {
$ret = FALSE;
self::$errors[] = 'Unable to load schema.';
}
$this->valid = $ret;
}
return $this->valid;
}
/**
* Saves the current XML datastream back to fedora. The XML must validate.
*
* @return boolean $success
*/
public function saveToFedora() {
module_load_include('inc', 'Fedora_Repository', 'api/fedora_item');
if ($this->validate()) {
$item = new Fedora_Item($this->pid);
$item->modify_datastream_by_value($this->dumpXml(), $this->dsid, $this->name, 'application/xml');
return TRUE;
}
return FALSE;
}
/**
* Purges veersions of the datastream newer than and including the start_date. If
* End date is specified, it can be used to purge a range of versions instead. Date should be in
* DATE_RFC822 format
*
* @param string $start_date
* @param string $end_date
* @return boolean $valid
*/
public function purgeVersions($start_date, $end_date = NULL) {
module_load_include('inc', 'fedora_repository', 'api/fedora_item');
$fedora_item = new Fedora_Item($this->pid);
return $fedora_item->purge_datastream( $this->dsid, $start_date, $end_date);
}
/**
* Gets the history of the datastream from fedora.
* Returns false on failure.
*
* @return string[] $ret
*/
public function getHistory() {
module_load_include('inc', 'fedora_repository', 'api/fedora_item');
$fedora_item = new Fedora_Item($this->pid);
$history = $fedora_item->get_datastream_history($this->dsid);
$ret = FALSE;
if ($history !== FALSE) {
$ret = array();
foreach ($history as $version) {
if ($version->versionID !== NULL) $ret[] = array('versionID' => $version->versionID, 'createDate' => $version->createDate);
}
}
return $ret;
}
/**
* Attempts to convert from the old XML schema to the new by
* traversing the XML DOM and building a new DOM. When done
* $this->xml is replaced by the newly created DOM..
*
* @return void
*/
abstract protected function convertFromOldSchema();
}
