simple-oai-pmh/oai2xml.php

124 lines
5.3 KiB
PHP

<?php
/**
* Simple OAI-PMH 2.0 Data Provider
* Copyright (C) 2011 Jianfeng Li
* Copyright (C) 2013 Daniel Neis Araujo <danielneis@gmail.com>
* Copyright (C) 2017 Sebastian Meyer <sebastian.meyer@opencultureconsulting.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
class OAI2XMLResponse {
public $doc; // DOMDocument. Handle of current XML Document object
public function __construct($uri, $verb, $request_args) {
$this->verb = $verb;
$this->doc = new DOMDocument('1.0', 'UTF-8');
$oai_node = $this->doc->createElement('OAI-PMH');
$oai_node->setAttribute('xmlns', 'http://www.openarchives.org/OAI/2.0/');
$oai_node->setAttribute('xmlns:xsi', 'http://www.w3.org/2001/XMLSchema-instance');
$oai_node->setAttribute('xsi:schemaLocation', 'http://www.openarchives.org/OAI/2.0/ http://www.openarchives.org/OAI/2.0/OAI-PMH.xsd');
$this->addChild($oai_node, 'responseDate', gmdate('Y-m-d\TH:i:s\Z'));
$this->doc->appendChild($oai_node);
$request = $this->addChild($this->doc->documentElement, 'request', $uri);
$request->setAttribute('verb', $this->verb);
foreach($request_args as $key => $value) {
$request->setAttribute($key, $value);
}
if (!empty($this->verb)) {
$this->verbNode = $this->addChild($this->doc->documentElement, $this->verb);
}
}
/**
* Add a child node to a parent node on a XML Doc: a worker function.
*
* @param $mom_node Type: DOMNode. The target node.
* @param $name Type: string. The name of child node is being added
* @param $value Type: string. Text for the adding node if it is a text node.
*
* @return DOMElement $added_node * The newly created node
*/
function addChild($mom_node, $name, $value = '') {
$added_node = $this->doc->createElement($name, $value);
$added_node = $mom_node->appendChild($added_node);
return $added_node;
}
/**
* Add direct child nodes to verb node (OAI-PMH), e.g. response to ListMetadataFormats.
* Different verbs can have different required child nodes.
* @see create_record, create_header
*
* @param $nodeName Type: string. The name of appending node.
* @param $value Type: string. The content of appending node.
*/
function addToVerbNode($nodeName, $value = null) {
return $this->addChild($this->verbNode, $nodeName, $value);
}
/**
* Headers are enclosed inside of <record> to the query of ListRecords, ListIdentifiers and etc.
*
* @param $identifier Type: string. The identifier string for node <identifier>.
* @param $timestamp Type: timestamp. Timestapme in UTC format for node <datastamp>.
* @param $add_to_node Type: DOMElement. Default value is null.
* In normal cases, $add_to_node is the <record> node created previously.
* When it is null, the newly created header node is attatched to $this->verbNode.
* Otherwise it will be attatched to the desired node defined in $add_to_node.
*/
function createHeader($identifier, $timestamp, $add_to_node = null) {
if(is_null($add_to_node)) {
$header_node = $this->addToVerbNode('header');
} else {
$header_node = $this->addChild($add_to_node, 'header');
}
$this->addChild($header_node, 'identifier', $identifier);
$this->addChild($header_node, 'datestamp', $timestamp);
return $header_node;
}
/**
* If there are too many records request could not finished a resumpToken is generated to let harvester know
*
* @param $token Type: string. A random number created somewhere?
* @param $expirationdatetime Type: string. A string representing time.
* @param $num_rows Type: integer. Number of records retrieved.
* @param $cursor Type: string. Cursor can be used for database to retrieve next time.
*/
function createResumptionToken($token, $expirationdatetime, $num_rows, $cursor = null) {
$resump_node = $this->addChild($this->verbNode, 'resumptionToken', $token);
if(isset($expirationdatetime)) {
$resump_node->setAttribute('expirationDate', $expirationdatetime);
}
$resump_node->setAttribute('completeListSize', $num_rows);
$resump_node->setAttribute('cursor', $cursor);
}
/**
* Imports a XML fragment into a parent node on a XML Doc: a worker function.
*
* @param $mom_node Type: DOMNode. The target node.
* @param $fragment Type: DOMDocument. The XML fragment is being added
*
* @return DOMElement $added_node * The newly created node
*/
function importFragment($mom_node, $fragment) {
$added_node = $mom_node->appendChild($this->doc->importNode($fragment->documentElement, true));
return $added_node;
}
}