* Store metadata tree in relational database.
*
* @see StoredFile
* @see XmlParser
* @see DataEngine
*/
class MetaData{
/**
* Constructor
*
* @param gb reference to GreenBox object
* @param gunid string, global unique id
* @param resDir string, resource directory
* @return this
*/
function MetaData(&$gb, $gunid, $resDir)
{
$this->dbc =& $gb->dbc;
$this->mdataTable = $gb->mdataTable;
$this->gunid = $gunid;
$this->resDir = $resDir;
$this->fname = $this->makeFname();
$this->exists =
$this->dbCheck($gunid) &&
is_file($this->fname) &&
is_readable($this->fname)
;
}
/**
* Parse and store metadata from XML file or XML string
*
* @param mdata string, local path to metadata XML file or XML string
* @param loc string - location: 'file'|'string'
* @param format string, metadata format for validation
* ('audioclip' | 'playlist' | 'webstream' | NULL)
* (NULL = no validation)
* @return true or PEAR::error
*/
function insert($mdata, $loc='file', $format=NULL)
{
if($this->exists) return FALSE;
$tree =& $this->parse($mdata, $loc);
if(PEAR::isError($tree)) return $tree;
$res = $this->validate($tree, $format);
if(PEAR::isError($res)) return $res;
$res = $this->storeDoc($tree);
if(PEAR::isError($res)) return $res;
switch($loc){
case"file":
if(! @copy($mdata, $this->fname)){
return PEAR::raiseError(
"MetaData::insert: file save failed".
" ($mdata, {$this->fname})",GBERR_FILEIO
);
}
break;
case"string":
$fname = $this->fname;
$e = FALSE;
if(!$fh = fopen($fname, "w")){ $e = TRUE; }
elseif(fwrite($fh, $mdata) === FALSE){ $e = TRUE; }
if($e){
return PEAR::raiseError(
"BasicStor::bsOpenDownload: can't write ($fname)",
GBERR_FILEIO);
}
fclose($fh);
break;
default:
return PEAR::raiseError(
"MetaData::insert: unsupported metadata location ($loc)"
);
}
$this->exists = TRUE;
return TRUE;
}
/**
* Call delete and insert
*
* @param mdata string, local path to metadata XML file or XML string
* @param loc string 'file'|'string'
* @return true or PEAR::error
*/
function replace($mdata, $loc='file')
{
if($this->exists){
$res = $this->delete();
if(PEAR::isError($res)) return $res;
}
return $this->insert($mdata, $loc);
}
/**
* Return true if metadata exists
*
* @return boolean
*/
function exists()
{
return $this->exists;
}
/**
* Delete all file's metadata
*
* @return true or PEAR::error
*/
function delete()
{
if(file_exists($this->fname)) @unlink($this->fname);
$res = $this->dbc->query("
DELETE FROM {$this->mdataTable}
WHERE gunid=x'{$this->gunid}'::bigint
");
if(PEAR::isError($res)) return $res;
$this->exists = FALSE;
return TRUE;
}
/**
* Return metadata XML string
*
* @return string
*/
function getMetaData()
{
// return $this->genXMLDoc(); // obsolete
if(file_exists($this->fname)){
$res = file_get_contents($this->fname);
//require_once "XML/Beautifier.php";
//$fmt = new XML_Beautifier();
//$res = $fmt->formatString($res);
return $res;
}else
return file_get_contents(dirname(__FILE__).'/emptyMdata.xml');
}
/**
* Get metadata element value and record id
*
* @param category string, metadata element name
* @param parid int, metadata record id of parent element
* @return hash {mid: int - record id, value: metadata alue}
*/
function getMetadataEl($category, $parid=NULL)
{
// handle predicate namespace shortcut
$a = XML_Util::splitQualifiedName(strtolower($category));
if(PEAR::isError($a)) return $a;
$catNs = $a['namespace'];
$cat = $a['localPart'];
$cond = "gunid=x'{$this->gunid}'::bigint AND predicate='$cat'";
if(!is_null($catNs)) $cond .= " AND predns='$catNs'";
if(!is_null($parid)) $cond .= " AND subjns='_I' AND subject='$parid'";
$sql = "
SELECT id as mid, object as value
FROM {$this->mdataTable}
WHERE $cond
ORDER BY id
";
$all = $this->dbc->getAll($sql);
if(PEAR::isError($all)) return $all;
return $all;
}
/**
* Set metadata value / delete metadata record
*
* @param mid int, metadata record id
* @param value string, new metadata value (NULL for delete)
* @return boolean
*/
function setMetadataEl($mid, $value=NULL)
{
if(!is_null($value)){
$sql = "
UPDATE {$this->mdataTable}
SET object='$value'
WHERE id={$mid}
";
$res = $this->dbc->query($sql);
}else{
$res = $this->deleteRecord($mid);
}
if(PEAR::isError($res)) return $res;
return TRUE;
}
/**
* Insert new metadata element
*
* @param parid int, metadata record id of parent element
* @param category string, metadata element name
* @param value string, new metadata value (NULL for delete)
* @param predxml srring, 'T' | 'A' | 'N' (tag, attr., namespace)
* @return int, new metadata record id
*/
function insertMetadataEl($parid, $category, $value=NULL, $predxml='T')
{
$cnt = $this->dbc->getOne("
SELECT count(*) FROM {$this->mdataTable}
WHERE gunid=x'{$this->gunid}'::bigint AND id=$parid
");
if(PEAR::isError($cnt)) return $cnt;
if($cnt < 1){
return PEAR::raiseError(
"MetaData::insertMetadataEl: container not found"
);
}
$a = XML_Util::splitQualifiedName(strtolower($category));
if(PEAR::isError($a)) return $a;
$catNs = $a['namespace'];
$cat = $a['localPart'];
$objns = (is_null($value) ? '_blank' : '_L' );
$nid= $this->storeRecord('_I', $parid, $catNs, $cat, $predxml,
$objns, $value);
if(PEAR::isError($nid)) return $nid;
return $nid;
}
/**
* Get metadata element value
*
* @param category string, metadata element name
* @param lang string, optional xml:lang value for select language version
* @param objns string, object namespace prefix - for internal use only
* @return array of matching records as hash with fields:
*
* - mid int, local metadata record id
* - value string, element value
* - attrs hasharray of element's attributes indexed by
* qualified name (e.g. xml:lang)
*
* @see BasicStor::bsGetMetadataValue
*/
function getMetadataValue($category, $lang=NULL, $objns='_L')
{
$all = $this->getMetadataEl($category);
$res = array();
// add attributes to result
foreach($all as $i=>$rec){
$pom = $this->getSubrows($rec['mid']);
if(PEAR::isError($pom)) return $pom;
$all[$i]['attrs'] = $pom['attrs'];
$atlang = $pom['attrs']['xml:lang'];
// select only matching lang (en is default)
if(
is_null($lang) ||
strtolower($lang) == strtolower($atlang) ||
(is_null($atlang) && strtolower($lang) == 'en')
){
$res[] = $all[$i];
}
}
return $res;
}
/**
* Set metadata element value
*
* @param category string, metadata element name (e.g. dc:title)
* @param value string/NULL value to store, if NULL then delete record
* @param lang string, optional xml:lang value for select language version
* @param mid int, metadata record id (OPTIONAL on unique elements)
* @param container string, container element name for insert
* @return boolean
*/
function setMetadataValue($category, $value, $lang=NULL, $mid=NULL,
$container='metadata')
{
// resolve aktual element:
$rows = $this->getMetadataValue($category, $lang);
$aktual = NULL;
if(count($rows)>1){
if(is_null($mid)){
if(MODIFY_LAST_MATCH){ $aktual = array_pop($rows); }
else{
return PEAR::raiseError(
"MetaData::setMdataValue:".
" nonunique category, mid required"
);
}
}else{
foreach($rows as $i=>$row){
if($mid == intval($row['mid'])) $aktual = $row;
}
}
}else $aktual = $rows[0];
if(!is_null($aktual)){
$res = $this->setMetadataEl($aktual['mid'], $value);
if(PEAR::isError($res)) return $res;
}else{
// resolve container:
$contArr = $this->getMetadataValue($container, NULL, '_blank');
if(PEAR::isError($contArr)) return $contArr;
$parid = $contArr[0]['mid'];
if(is_null($parid)){
return PEAR::raiseError(
"MetaData::setMdataValue: container ($container) not found"
);
}
$nid = $this->insertMetadataEl($parid, $category, $value);
if(PEAR::isError($nid)) return $nid;
if(!is_null($lang)){
$res = $this->insertMetadataEl($nid, 'xml:lang', $lang, 'A');
if(PEAR::isError($res)) return $res;
}
}
return TRUE;
}
/**
* Regenerate XML metadata file after metadata value change
*
* @return boolean
*/
function regenerateXmlFile()
{
$fn = $this->fname;
$xml = $this->genXMLDoc();
if (!$fh = fopen($fn, 'w')) {
return PEAR::raiseError(
"MetaData::regenerateXmlFile: cannot open for write ($fn)"
);
}
if(fwrite($fh, $xml) === FALSE) {
return PEAR::raiseError(
"MetaData::regenerateXmlFile: write error ($fn)"
);
}
fclose($fh);
return TRUE;
}
/**
* Contruct filepath of metadata file
*
* @return string
*/
function makeFname()
{
return "{$this->resDir}/{$this->gunid}.xml";
}
/**
* Return filename
*
* @return string
*/
function getFname()
{
return $this->fname;
}
/**
* Check if there are any file's metadata in database
*
* @param gunid string, global unique id
* @return boolean
*/
function dbCheck($gunid)
{
$cnt = $this->dbc->getOne("
SELECT count(*)as cnt
FROM {$this->mdataTable}
WHERE gunid=x'$gunid'::bigint
");
if(PEAR::isError($cnt)) return $cnt;
return (intval($cnt) > 0);
}
/* ============================================= parse and store metadata */
/**
* Parse XML metadata
*
* @param mdata string, local path to metadata XML file or XML string
* @param loc string, location: 'file'|'string'
* @return array reference, parse result tree (or PEAR::error)
*/
function &parse($mdata='', $loc='file')
{
switch($loc){
case"file":
if(!is_file($mdata)){
return PEAR::raiseError(
"MetaData::parse: metadata file not found ($mdata)"
);
}
if(!is_readable($mdata)){
return PEAR::raiseError(
"MetaData::parse: can't read metadata file ($mdata)"
);
}
$mdata = file_get_contents($mdata);
case"string":
require_once"XmlParser.php";
$parser =& new XmlParser($mdata);
if($parser->isError()){
return PEAR::raiseError(
"MetaData::parse: ".$parser->getError()
);
}
$tree = $parser->getTree();
break;
default:
return PEAR::raiseError(
"MetaData::parse: unsupported metadata location ($loc)"
);
}
return $tree;
}
/**
* Validate parsed metadata
*
* @param tree array, parsed tree
* @param format string, metadata format for validation
* ('audioclip' | 'playlist' | 'webstream' | NULL)
* (NULL = no validation)
* @return true or PEAR::error
*/
function validate(&$tree, $format=NULL)
{
//echo"";var_dump($tree);exit;
if(VALIDATE && !is_null($format)){
require_once"Validator.php";
$val =& new Validator($format, $this->gunid);
if(PEAR::isError($val)) return $val;
$res = $val->validate($tree);
if(PEAR::isError($res)) return $res;
}
return TRUE;
}
/**
* Insert parsed metadata into database
*
* @param tree array, parsed tree
* @return true or PEAR::error
*/
function storeDoc(&$tree)
{
$this->dbc->query("BEGIN");
$res = $this->storeNode($tree);
if(PEAR::isError($res)){
$this->dbc->query("ROLLBACK"); return $res;
}
$res = $this->dbc->query("COMMIT");
if(PEAR::isError($res)){ $this->dbc->query("ROLLBACK"); return $res; }
return TRUE;
return $root;
}
/**
* Process one node of metadata XML for insert or update.
*
* @param node object, node in tree returned by XmlParser
* @param parid int, parent id
* @param nSpaces array of name spaces definitions
* @return int, local metadata record id
*/
function storeNode(&$node, $parid=NULL, $nSpaces=array())
{
//echo $node->node_name().", ".$node->node_type().", ".$node->prefix().", $parid.\n";
$nSpaces = array_merge($nSpaces, $node->nSpaces);
// null parid = root node of metadata tree
$subjns = (is_null($parid)? '_G' : '_I');
$subject = (is_null($parid)? $this->gunid : $parid);
$object = $node->content;
if(is_null($object) || $object == ''){
$objns = '_blank';
$object = 'NULL';
}else $objns = '_L';
$id = $this->storeRecord($subjns, $subject,
$node->ns, $node->name, 'T', $objns, $object);
// process attributes
foreach($node->attrs as $atn=>$ato){
$this->storeRecord('_I', $id,
$ato->ns, $ato->name, 'A', '_L', $ato->val);
}
// process child nodes
foreach($node->children as $ch){
$this->storeNode($ch, $id, $nSpaces);
}
// process namespace definitions
foreach($node->nSpaces as $ns=>$uri){
$this->storeRecord('_I', $id,
'xmlns', $ns, 'N', '_L', $uri);
}
return $id;
}
/**
* Update object namespace and value of one metadata record
* identified by metadata record id
*
* @param mdid int, metadata record id
* @param object string, object value, e.g. title string
* @param objns string, object namespace prefix, have to be defined
* in file's metadata
* @return true or PEAR::error
*/
function updateRecord($mdid, $object, $objns='_L')
{
$res = $this->dbc->query("UPDATE {$this->mdataTable}
SET objns = '$objns', object = '$object'
WHERE gunid = x'{$this->gunid}'::bigint AND id='$mdid'
");
if(PEAR::isError($res)) return $res;
return TRUE;
}
/**
* Insert or update of one metadata record completely
*
* @param subjns string, subject namespace prefix, have to be defined
* in file's metadata (or reserved prefix)
* @param subject string, subject value, e.g. gunid
* @param predns string, predicate namespace prefix, have to be defined
* in file's metadata (or reserved prefix)
* @param predicate string, predicate value, e.g. name of DC element
* @param predxml string 'T'|'A'|'N' - XML tag, attribute or NS def.
* @param objns string, object namespace prefix, have to be defined
* in file's metadata (or reserved prefix)
* @param object string, object value, e.g. title of song
* @return int, new metadata record id
*/
function storeRecord($subjns, $subject, $predns, $predicate, $predxml='T',
$objns=NULL, $object=NULL)
{
//echo "$subjns, $subject, $predns, $predicate, $predxml, $objns, $object\n";
$predns = strtolower($predns);
$predicate = strtolower($predicate);
$predns_sql = (is_null($predns) ? "NULL" : "'$predns'" );
$objns_sql = (is_null($objns) ? "NULL" : "'$objns'" );
$object_sql = (is_null($object)? "NULL" : "'$object'");
$id = $this->dbc->nextId("{$this->mdataTable}_id_seq");
if(PEAR::isError($id)) return $id;
$res = $this->dbc->query("
INSERT INTO {$this->mdataTable}
(id , gunid , subjns , subject ,
predns , predicate , predxml ,
objns , object
)
VALUES
($id, x'{$this->gunid}'::bigint, '$subjns', '$subject',
$predns_sql, '$predicate', '$predxml',
$objns_sql, $object_sql
)
");
if(PEAR::isError($res)) return $res;
return $id;
}
/**
* Delete metadata record recursively
*
* @param mid int local metadata record id
* @return boolean
*/
function deleteRecord($mid)
{
$sql = "
SELECT id FROM {$this->mdataTable}
WHERE subjns='_I' AND subject='{$mid}' AND
gunid=x'{$this->gunid}'::bigint
";
$rh = $this->dbc->query($sql);
if(PEAR::isError($rh)) return $rh;
while($row = $rh->fetchRow()){
$r = $this->deleteRecord($row['id']);
if(PEAR::isError($r)) return $r;
}
$rh->free();
$sql = "
DELETE FROM {$this->mdataTable}
WHERE id={$mid} AND
gunid=x'{$this->gunid}'::bigint
";
$res = $this->dbc->query($sql);
if(PEAR::isError($res)) return $res;
return TRUE;
}
/* =========================================== XML reconstruction from db */
/**
* Generate PHP array from metadata database
*
* @return array with metadata tree
*/
function genPhpArray()
{
$res = array();
$row = $this->dbc->getRow("
SELECT * FROM {$this->mdataTable}
WHERE gunid=x'{$this->gunid}'::bigint
AND subjns='_G' AND subject='{$this->gunid}'
");
if(PEAR::isError($row)) return $row;
if(is_null($row)){
}else{
$node = $this->genXMLNode($row, FALSE);
if(PEAR::isError($node)) return $node;
$res = $node;
}
return $res;
}
/**
* Generate XML document from metadata database
*
* @return string with XML document
*/
function genXMLDoc()
{
require_once "XML/Util.php";
$res = XML_Util::getXMLDeclaration("1.0", "UTF-8")."\n";
$row = $this->dbc->getRow("
SELECT * FROM {$this->mdataTable}
WHERE gunid=x'{$this->gunid}'::bigint
AND subjns='_G' AND subject='{$this->gunid}'
");
if(PEAR::isError($row)) return $row;
if(is_null($row)){
$node = XML_Util::createTagFromArray(array(
'localpart'=>'none'
));
}else{
$node = $this->genXMLNode($row);
if(PEAR::isError($node)) return $node;
}
$res .= $node;
require_once "XML/Beautifier.php";
$fmt = new XML_Beautifier();
$res = $fmt->formatString($res);
return $res;
}
/**
* Generate XML element from database
*
* @param row array, hash with metadata record fields
* @param genXML boolean, if TRUE generate XML else PHP array
* @return string, XML serialization of node
*/
function genXMLNode($row, $genXML=TRUE)
{
if(DEBUG) echo"genXMLNode:\n";
if(DEBUG) var_dump($row);
extract($row);
$arr = $this->getSubrows($id, $genXML);
if(PEAR::isError($arr)) return $arr;
if(DEBUG) var_dump($arr);
extract($arr);
if($genXML){
$node = XML_Util::createTagFromArray(array(
'namespace' => $predns,
'localPart' => $predicate,
'attributes'=> $attrs,
'content' => ($object == 'NULL' ? $children : $object),
), FALSE);
}else{
$node = array_merge(
array(
'elementname' => ($predns ? "$predns:" : '').$predicate,
'content' => $object,
'children'=> $children,
), $arr
);
}
return $node;
}
/**
* Return values of attributes, child nodes and namespaces for
* one metadata record
*
* @param parid int, local id of parent metadata record
* @param genXML boolean, if TRUE generate XML else PHP array for
* children
* @return hash with three fields:
* - attr hash, attributes
* - children array, child nodes
* - nSpaces hash, namespace definitions
*/
function getSubrows($parid, $genXML=TRUE)
{
if(DEBUG) echo" getSubrows:\n";
$qh = $this->dbc->query($q = "
SELECT
id, predxml, predns, predicate, objns,
coalesce(object, 'NULL')as object
FROM {$this->mdataTable}
WHERE
subjns='_I' AND subject='$parid' AND
gunid=x'{$this->gunid}'::bigint
ORDER BY id
");
if(PEAR::isError($qh)) return $qh;
$attrs = array();
$children = array();
$nSpaces = array();
if(DEBUG) echo " #=".$qh->numRows()."\n$q\n";
while($row = $qh->fetchRow()){
if(DEBUG) var_dump($row);
extract($row);
switch($predxml){
case"N":
$nSpaces["$predicate"] = $object;
case"A":
$sep=':';
if($predns=='' || $predicate=='') $sep='';
$attrs["{$predns}{$sep}{$predicate}"] = $object;
break;
case"T":
$children[] = $this->genXMLNode($row, $genXML);
break;
default:
return PEAR::raiseError(
"MetaData::getSubrows: unknown predxml ($predxml)");
} // switch
}
$qh->free();
if($genXML) $children = join(" ", $children);
return compact('attrs', 'children', 'nSpaces');
}
/* ========================================================= test methods */
/**
* Test method
*
* @return true or PEAR::error
*/
function test()
{
$res = $this->replace(getcwd().'/mdata2.xml');
if(PEAR::isError($res)) return $res;
$res = $this->getMetaData();
if(PEAR::isError($res)) return $res;
return TRUE;
}
}
?>