| Current File : //opt/alt/php82/usr/share/pear/File/MARC/List.php |
<?php
/* vim: set expandtab shiftwidth=4 tabstop=4 softtabstop=4 foldmethod=marker: */
/**
* Parser for MARC records
*
* This package is based on the PHP MARC package, originally called "php-marc",
* that is part of the Emilda Project (http://www.emilda.org). Christoffer
* Landtman generously agreed to make the "php-marc" code available under the
* GNU LGPL so it could be used as the basis of this PEAR package.
*
* PHP version 5
*
* LICENSE: This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* @category File_Formats
* @package File_MARC
* @author Christoffer Landtman <landtman@realnode.com>
* @author Dan Scott <dscott@laurentian.ca>
* @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 SplDoublyLinkedList
/**
* The File_MARC_List class extends the SplDoublyLinkedList 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.
*
* <code>
* // 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";
* }
* </code>
*
* @category File_Formats
* @package File_MARC
* @author Dan Scott <dscott@laurentian.ca>
* @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 SplDoublyLinkedList
{
// {{{ properties
/**
* Position of the subfield
* @var int
*/
protected $position;
// }}}
// {{{ key()
/**
* Returns the tag for a {@link File_MARC_Field} object, or the code
* for a {@link File_MARC_Subfield} object.
*
* This method enables you to use a foreach iterator to retrieve
* the tag or code as the key for the iterator.
*
* @return string returns the tag or code
*/
function key()
{
if ($this->current() instanceof File_MARC_Field) {
return $this->current()->getTag();
} elseif ($this->current() instanceof File_MARC_Subfield) {
return $this->current()->getCode();
}
return false;
}
// }}}
// {{{ function insertNode()
/**
* Inserts a node into the linked list, based on a reference node that
* already exists in the list.
*
* @param mixed $new_node New node to add to the list
* @param mixed $existing_node Reference position node
* @param bool $before Insert new node before or after the existing node
*
* @return bool Success or failure
**/
public function insertNode($new_node, $existing_node, $before = false)
{
$pos = 0;
$exist_pos = $existing_node->getPosition();
$this->rewind();
// Now add the node according to the requested mode
switch ($before) {
case true:
$this->add($exist_pos, $new_node);
break;
// after
case false:
if ($this->offsetExists($exist_pos + 1)) {
$this->add($exist_pos + 1, $new_node);
} else {
$this->appendNode($new_node);
return true;
}
break;
}
// Fix positions
$this->rewind();
while ($n = $this->current()) {
$n->setPosition($pos);
$this->next();
$pos++;
}
return true;
}
// }}}
// {{{ function appendNode()
/**
* Adds a node onto the linked list.
*
* @param mixed $new_node New node to add to the list
*
* @return void
**/
public function appendNode($new_node)
{
$pos = $this->count();
$new_node->setPosition($pos);
$this->push($new_node);
}
// }}}
// {{{ function prependNode()
/**
* Adds a node to the start of the linked list.
*
* @param mixed $new_node New node to add to the list
*
* @return void
**/
public function prependNode($new_node)
{
$this->insertNode($new_node, $this->bottom(), true);
}
// }}}
// {{{ function deleteNode()
/**
* Deletes a node from the linked list.
*
* @param mixed $node Node to delete from the list
*
* @return void
**/
public function deleteNode($node)
{
$target_pos = $node->getPosition();
$this->rewind();
$pos = 0;
// Omit target node and adjust pos of remainder
$done = false;
try {
while ($n = $this->current()) {
if ($pos == $target_pos && !$done) {
$done = true;
$this->next();
$this->offsetUnset($pos);
} elseif ($pos >= $target_pos) {
$n->setPosition($pos);
$pos++;
$this->next();
} else {
$pos++;
$this->next();
}
}
}
catch (Exception $e) {
// no-op - shift() throws an exception, sigh
}
}
// }}}
// {{{ setPosition()
/**
* Sets position of the subfield
*
* @param string $pos new position of the subfield
*
* @return void
*/
function setPosition($pos)
{
$this->position = $pos;
}
// }}}
// {{{ getPosition()
/**
* Return position of the subfield
*
* @return int data
*/
function getPosition()
{
return $this->position;
}
// }}}
}
// }}}