/lib/php-views/ezproxy-export.php

<?php



/**

 * Outputs an EZProxy config file from Metalib/Xerxes KB. See:

 * http://code.google.com/p/xerxes-portal/wiki/EzProxyExport

 *

 * @author Jonathan Rochkind

 * @copyright 2009 Johns Hopkins University

 * @link http://xerxes.calstate.edu

 * @license http://www.gnu.org/licenses/

 * @version $Id: ezproxy-export.php 1552 2010-12-07 22:54:43Z rochkind@jhu.edu $

 * @package Xerxes

 */



/* 

For documentation of the EZProxy config format, see:

http://www.oclc.org/us/en/support/documentation/ezproxy/cfg/database.htm

http://www.oclc.org/us/en/support/documentation/ezproxy/cfg/groups.htm

*/



// inherits $objRegistry and $objXml



header("Content-type: text/plain");



// simpleXml is a lot easier to work with than DOM



$objDatabases = simplexml_import_dom($objXml->documentElement);





// First sort and process

$warnings = array();

$exporter = new EzProxyExportGen($objRegistry);

foreach ( $objDatabases->databases->database as $xmlDatabase) {

  

  try {

    if ($xmlDatabase->proxy == '1') {

      $exporter->addDbXml( $xmlDatabase );

    }

  }

  catch (Exception $e) {

    array_push($warnings, $e->getMessage());

  }

}



$exporter->createConfig($warnings);



if (count($warnings) > 0 ) {

  print "# NOTE: Warnings for Xerxes EZProxy output: \n#\n";

  foreach ($warnings as $w) {

    print "# " . str_replace("\n", " ", $w) . "\n#\n"; 

  }

}



class EzProxyExportGen {

  private $objRegistry = null;

  private $index_by_domain = array();

  private $index_by_restriction = array();

  

  public function __construct($argRegistry) {

    $this->objRegistry = $argRegistry; 

  }

  

  // Takes a simple xml object representing a database, in Xerxes. 

  public function addDbXml($xmlDatabase) {    

      $dbHash = $this->makeDbHash($xmlDatabase);

      

      // To begin with, index it by domain, to get urls in same

      // domain together.

      $domain = $dbHash['domain'];

      if (! array_key_exists($domain, $this->index_by_domain)) {

        $this->index_by_domain[ $domain ] = array();

      }

      array_push( $this->index_by_domain[$domain], $dbHash );

  }

  

  public function createConfig(&$warnings) {

    // We have our individual entries grouped by domains. 

    // We need to take these domain groups, and group them

    // by access control. 

    foreach ($this->index_by_domain as $domainList) {

      

      $first_entry = $domainList[0];      

      $groups = array_merge($first_entry['group_restrictions']); // array_merge to make a copy



      for ($i = 1; $i < count($domainList) - 1; $i++ ) {

          $entry = $domainList[$i];

          if ( count( array_diff($entry['group_restrictions'], $groups)) > 0) {

                        

            array_push($warnings, "Conflicting group restrictions in two resources with same domain can not be enforced. Ezproxy restrictions may be more generous than intended: 1) " . $first_entry["title"] . "(" . $first_entry["metalib_id"] . ") 2) " . $entry["title"] . ")" . $entry["metalib_id"] .")");

            

            $groups = array_unique(array_merge( $groups, $entry['group_restrictions']));            

          }

      }

      

      // We can't combine default with other restrictions, default

      // trumps it. 

      if ( in_array('Default', $groups)) {

        $restriction_key = 'Default';

      }

      else {

        sort($groups);

        $restriction_key = join(';',$groups);

      }

      

      if (! array_key_exists($restriction_key, $this->index_by_restriction)) {

        $this->index_by_restriction[$restriction_key] = array();

      }

      array_push( $this->index_by_restriction[$restriction_key], $domainList );



    }

    // Now we've grouped by restriction, let's output. 

    

    foreach (array_keys( $this->index_by_restriction ) as $restriction_key) {

      $groups = explode(';', $restriction_key);

      

      $ezproxy_groups = array();

      foreach ($groups as $group) {

        array_push($ezproxy_groups, $this->getEzProxyGroup($group));

      }

      if (count($ezproxy_groups) > 0) {

        print "\n\n#EZProxy group for metalib secondary affiliations: $restriction_key\n";

        print ("Group " . implode("+", $ezproxy_groups) . "\n\n");

      }

      

      foreach ( $this->index_by_restriction[$restriction_key] as $domainList ) {

        $first_entry = $domainList[0];

        

        print "Title ". $first_entry['title'] . " (" . $first_entry['metalib_id'] . ")";

        if ( count($domainList) > 1 ) {

          print " (and others) ";

          print "\n# Complete list of included Metalib IRD IDs: ";

          foreach ($domainList as $domainHash) {

            print $domainHash["metalib_id"] . " ";

          }

        }

        print "\n";

        

        print "URL " . $first_entry['url'] . "\n";

        print "Domain " . $first_entry['domain'] . "\n";

        

        // Any other hosts in this domain group? Find em and unique em. 

        $included_hosts = array( $first_entry['url_host'] );

        for($i = 2; $i < count($domainList) - 1 ; $i++) {

          $new_host = $domainList[$i]['url_host'];

          if ( ! in_array($new_host, $included_hosts)) {

            array_push($included_hosts, $new_host);

            print "Host " . $new_host . "\n"; 

          }

        }

        // Derived hosts. 

        $new_host = $first_entry['domain'];

        if (! in_array( $new_host, $included_hosts )) {

          array_push($included_hosts, $new_host);

          print "Host " . $new_host . "\n";

        }

        $new_host = "www." . $first_entry['domain'];

        if (! in_array($new_host, $included_hosts)) {

          array_push($included_hosts, $new_host);

          print "Host " . $new_host . "\n";         

        }

        

        

        print "\n\n";

      }

    }

    

  }

  

  

  

  // Takes a simple xml object representing a database, in Xerxes. 

  public function makeDbHash($xmlDatabase) {

    $hash = array();

    $hash['title'] = $xmlDatabase->title_display;

    if (! $hash['title'] ) $hash['title'] = 'unknown/missing';

    

    if ( $this->shouldOmitResourceID( $xmlDatabase->metalib_id ) ) {

      throw new Exception("Omitted as per Xerxes ezp_exp_resourceid_omit config: " . $xmlDatabase->metalib_id);

    }

    

    if (! $xmlDatabase->link_native_home ) {

       throw new Exception("Could not include db in ezproxy export, missing title: " . $xmlDatabase->metalib_id);

    }

    

    $parsed_url = parse_url($xmlDatabase->link_native_home);

    

    

    if (! array_key_exists('host', $parsed_url)) {

        throw new Exception("Could not include db in ezproxy export. Malformed url? " . $xmlDatabase->metalib_id . " url: " . $xmlDatabase->link_native_home );

    }

    

    $hash['metalib_id'] = (string) $xmlDatabase->metalib_id;

    $hash['url'] = (string) $xmlDatabase->link_native_home;

    $hash['url_host'] = $parsed_url['host'];

    $hash['domain'] = $this->getDomain($parsed_url);

    

    // Any access restrictions?

    $hash['group_restrictions'] = array();        

    foreach ($xmlDatabase->group_restriction as $restriction) {

      array_push( $hash['group_restrictions'], (string) $restriction); 

    }

    if (count($hash['group_restrictions']) == 0) {

      $hash['group_restrictions'] = array('Default');

    }

    

    return $hash;

  }

  

  protected function getDomain($parsed_url) {

    $host = $parsed_url['host'];

    

    // If host is numeric, we can't create a domain statement.

    // It's bad to use a numeric host, but oh well. 

    if (preg_match("/^(\d|\.)+$/", $host)) {

      return $host;

    }

    $components = explode('.', $host);

    

    if ( count($components) > 2 ) {

      $domain = join('.', array_slice($components, 1));

      // Make sure it's not on our configured avoid list

      if (! $this->shouldAvoidDomain($domain)) {

        return $domain;

      }

      elseif (! $this->shouldAvoidDomain($host)) {

        return $host;

      }

      else {

        throw new Exception("Can't include resource because domain is in ezproxy domain avoid list: ". $host );

      }

    }

    elseif (! $this->shouldAvoidDomain($host)) {

      // No domain statement needed, two-element host, like "ebsco.com".  

      return $host;

    }

    else {

      throw new Exception("Can't include resource because domain is in ezproxy domain avoid list: ". $host);

    }

  }

  

  protected function shouldAvoidDomain($domain) {

     $avoidList = $this->objRegistry->getConfig('ezp_exp_domain_avoid', false, '');

      foreach( explode(',', $avoidList) as $avoid) {

        if (trim($avoid) == $domain) {

          # nevermind, can't use that domain, just use the host.

          return true;

        }

      }

      return false;

  }

  

  protected function shouldOmitResourceId($resourceID) {

   $avoidList = $this->objRegistry->getConfig('ezp_exp_resourceid_omit', false, '');

    foreach( explode(',', $avoidList) as $avoid) {

      if (trim($avoid) == $resourceID) {

        # nevermind, can't use that domain, just use the host.

        return true;

      }

    }

    return false;

  }

  



  protected function getEzProxyGroup($metalib_group) {

    if ($metalib_group == "Default") {

      $config = $this->objRegistry->getConfig("ezp_exp_default_group", false);

      if ( $config ) {

        return $config;

      }

      else {

        return "Default";

      }

    }

    else {

      $xml = $this->objRegistry->getGroupXml($metalib_group);

      if ($xml && $xml->ezp_exp_group ) {

        return $xml->ezp_exp_group;

      }

      else {

        return $metalib_group;

      }

    }

  }

}