simple-oai-pmh/oai2.php

<?php
/**
 * OAI Data Provider command processor
 *
 * OAI Data Provider is not designed for human to retrieve data.
 *
 * This is an implementation of OAI Data Provider version 2.0.
 * @see http://www.openarchives.org/OAI/2.0/openarchivesprotocol.htm
 * 
 * It needs other files:
 * - oaidp-config.php : Configuration of provider
 * - oaidp-util.php : Utility functions
 * - xml_creater.php : XML generating functions
 * - Actions:
 * 	- identify.php : About the provider
 * 	- listmetadataformats.php : List supported metadata formats
 * 	- listrecords.php : List identifiers and records
 * 	- listsets.php : List sets
 * 	- getrecord.php : Get a record
 *		- Your own implementation for providing metadata records.
 *
 * It also initiates:
 *	- PDO datbase connection object $db.
 *	- ANDS_XML XML document handler $outputObj.  
 *
 * \todo <b>Remember:</b> to define your own classess for generating metadata records.
 * In common cases, you have to implement your own code to act fully and correctly.
 * For generic usage, you can try the ANDS_Response_XML defined in xml_creater.php.
 */

/**
 * An array for collecting erros which can be reported later. It will be checked before a new action is taken.
 */
$errors = array();

/**
 * Supported attributes associate to verbs.
 */
$attribs = array ('from', 'identifier', 'metadataPrefix', 'set', 'resumptionToken', 'until');

if (in_array($_SERVER['REQUEST_METHOD'],array('GET','POST'))) {
    $args = $_REQUEST;
} else {
    $errors[] = oai_error('badRequestMethod', $_SERVER['REQUEST_METHOD']);
}

require_once('oaidp-util.php');
// Always using htmlentities() function to encodes the HTML entities submitted by others.
// No one can be trusted.
foreach ($args as $key => $val) {
    $checking = htmlspecialchars(stripslashes($val));
    if (!is_valid_attrb($checking)) {
        $errors[] = oai_error('badArgument', $checking);
    } else {$args[$key] = $checking; }
}
if (!empty($errors)) {
    oai_exit();
}

foreach($attribs as $val) {
    unset($$val);
}

require_once('oaidp-config.php');
require_once('config/metadataformats.php');
require_once('config/sets.php');
require_once('config/database.php');

// For generic usage or just trying:
// require_once('xml_creater.php');
// In common cases, you have to implement your own code to act fully and correctly.
require_once('ands_tpa.php');

// Default, there is no compression supported
$compress = FALSE;
if (isset($compression) && is_array($compression)) {
    if (in_array('gzip', $compression) && ini_get('output_buffering')) {
        $compress = TRUE;
    }
}

if (SHOW_QUERY_ERROR) {
    echo "Args:\n"; print_r($args);
}


if (isset($args['verb'])) {

    require_once('oai2server.php');
    $oai2 = new OAI2Server($args);

    switch ($args['verb']) {

        case 'Identify':

            // we never use compression in Identify
            $compress = FALSE;

            if (count($args)>1) {
                foreach($args as $key => $val) {
                    if(strcmp($key,"verb")!=0) {
                        $errors[] = oai_error('badArgument', $key, $val);
                    }	
                }
            }

            if (empty($errors)) {
                $outputObj = $oai2->identify($show_identifier, $repositoryIdentifier, $delimiter, $sampleIdentifier);
            }
            break;

        case 'ListMetadataFormats':

            $checkList = array("ops"=>array("identifier"));
            checkArgs($args, $checkList);
            if (empty($errors)) {
                $outputObj = $oai2->listMetadataFormats();
            }
            break;

        case 'ListSets':
            if (isset($args['resumptionToken']) && count($args) > 2) {
                $errors[] = oai_error('exclusiveArgument');
            }
            $checkList = array("ops"=>array("resumptionToken"));
            checkArgs($args, $checkList);
            if (empty($errors)) {
                $outputObj = $oai2->listSets($SETS);
            }
            break;

        case 'GetRecord':
            $checkList = array("required"=>array("metadataPrefix","identifier"));
            checkArgs($args, $checkList);
            if (empty($errors)) {
                $outputObj = $oai2->getRecord();
            }
            break;

        case 'ListIdentifiers':
        case 'ListRecords':
            if(isset($args['resumptionToken'])) {
                if (count($args) > 2) {
                    $errors[] = oai_error('exclusiveArgument');
                }
                $checkList = array("ops"=>array("resumptionToken"));
            } else {
                $checkList = array("required"=>array("metadataPrefix"),"ops"=>array("from","until","set"));
            }
            checkArgs($args, $checkList);
            if (empty($errors)) {
                $outputObj = $oai2->listRecords($SETS);
            }
            break;

        default:
            // we never use compression with errors
            $compress = FALSE;
            $errors[] = oai_error('badVerb', $args['verb']);
    } /*switch */
} else {
    $errors[] = oai_error('noVerb');
}

if (!empty($errors)) {
    oai_exit();
}

if ($compress) {
    ob_start('ob_gzhandler');
}

header(CONTENT_TYPE);

if (isset($outputObj)) {
    $outputObj->display();
} else {
    exit("There is a bug in codes");
}

if ($compress) {
    ob_end_flush();
}