GoogleScholarPlugin.inc.php

<?php
 
import('lib.pkp.classes.plugins.GenericPlugin');
 
class GoogleScholarPlugin extends GenericPlugin {
   function register($category, $path, $mainContextId = null) {
      if (parent::register($category, $path, $mainContextId)) {
         if ($this->getEnabled($mainContextId)) {
            HookRegistry::register('ArticleHandler::view', array(&$this, 'submissionView'));
            HookRegistry::register('PreprintHandler::view', array(&$this, 'submissionView'));
         }
         return true;
      }
      return false;
   }
 
   function getContextSpecificPluginSettingsFile() {
      return $this->getPluginPath() . '/settings.xml';
   }
 
   function submissionView($hookName, $args) {
      $application = Application::get();
      $applicationName = $application->getName();
      $request = $args[0];
      if ($applicationName == "ojs2"){
         $issue = $args[1];
         $submission = $args[2];
         $submissionPath = 'article';
      }
      if ($applicationName == "ops"){
         $submission = $args[1];
         $submissionPath = 'preprint';
      }     
      $requestArgs = $request->getRequestedArgs();
      $context = $request->getContext();
 
      // Only add Google Scholar metadata tags to the canonical URL for the latest version
      // See discussion: https://github.com/pkp/pkp-lib/issues/4870
      if (count($requestArgs) > 1 && $requestArgs[1] === 'version') {
         return;
      }
 
      $templateMgr = TemplateManager::getManager($request);
      $templateMgr->addHeader('googleScholarRevision', '<meta name="gs_meta_revision" content="1.1"/>');
 
      // Context identification
      if ($applicationName == "ojs2"){
         $templateMgr->addHeader('googleScholarJournalTitle', '<meta name="citation_journal_title" content="' . htmlspecialchars($context->getName($context->getPrimaryLocale())) . '"/>');
         if (($abbreviation = $context->getData('abbreviation', $context->getPrimaryLocale())) || ($abbreviation = $context->getData('acronym', $context->getPrimaryLocale()))) {
            $templateMgr->addHeader('googleScholarJournalAbbrev', '<meta name="citation_journal_abbrev" content="' . htmlspecialchars($abbreviation) . '"/>');
         }
         if ( ($issn = $context->getData('onlineIssn')) || ($issn = $context->getData('printIssn')) || ($issn = $context->getData('issn'))) {
            $templateMgr->addHeader('googleScholarIssn', '<meta name="citation_issn" content="' . htmlspecialchars($issn) . '"/> ');
         }
      }
      if ($applicationName == "ops"){
         $templateMgr->addHeader('googleScholarPublisher', '<meta name="citation_publisher" content="' . htmlspecialchars($context->getName($context->getPrimaryLocale())) . '"/>');
      }
 
 
      // Contributors
      foreach ($submission->getAuthors() as $i => $author) {
         $templateMgr->addHeader('googleScholarAuthor' . $i, '<meta name="citation_author" content="' . htmlspecialchars($author->getFullName(false)) .'"/>');
         if ($affiliation = htmlspecialchars($author->getAffiliation($submission->getLocale()))) {
            $templateMgr->addHeader('googleScholarAuthor' . $i . 'Affiliation', '<meta name="citation_author_institution" content="' . $affiliation . '"/>');
         }
      }
 
      // Submission title
      $templateMgr->addHeader('googleScholarTitle', '<meta name="citation_title" content="' . htmlspecialchars($submission->getFullTitle($submission->getLocale())) . '"/>');
      if ($locale = $submission->getLocale()) $templateMgr->addHeader('googleScholarLanguage', '<meta name="citation_language" content="' . htmlspecialchars(substr($locale, 0, 2)) . '"/>');
 
      // Submission publish date and issue information
      if ($applicationName == "ojs2"){
         if (is_a($submission, 'Submission') && ($datePublished = $submission->getDatePublished()) && (!$issue->getYear() || $issue->getYear() == strftime('%Y', strtotime($datePublished)))) {
            $templateMgr->addHeader('googleScholarDate', '<meta name="citation_date" content="' . strftime('%Y/%m/%d', strtotime($datePublished)) . '"/>');
         } elseif ($issue && $issue->getYear()) {
            $templateMgr->addHeader('googleScholarDate', '<meta name="citation_date" content="' . htmlspecialchars($issue->getYear()) . '"/>');
         } elseif ($issue && ($datePublished = $issue->getDatePublished())) {
            $templateMgr->addHeader('googleScholarDate', '<meta name="citation_date" content="' . strftime('%Y/%m/%d', strtotime($datePublished)) . '"/>');
         }
         if ($issue) {
            if ($issue->getShowVolume()) $templateMgr->addHeader('googleScholarVolume', '<meta name="citation_volume" content="' . htmlspecialchars($issue->getVolume()) . '"/>');
            if ($issue->getShowNumber()) $templateMgr->addHeader('googleScholarNumber', '<meta name="citation_issue" content="' . htmlspecialchars($issue->getNumber()) . '"/>');
         }
         if ($submission->getPages()) {
            if ($startPage = $submission->getStartingPage()) $templateMgr->addHeader('googleScholarStartPage', '<meta name="citation_firstpage" content="' . htmlspecialchars($startPage) . '"/>');
            if ($endPage = $submission->getEndingPage()) $templateMgr->addHeader('googleScholarEndPage', '<meta name="citation_lastpage" content="' . htmlspecialchars($endPage) . '"/>');
         }
      }
      if ($applicationName == "ops"){
         $templateMgr->addHeader('googleScholarDate', '<meta name="citation_online_date" content="' . strftime('%Y/%m/%d', strtotime($submission->getDatePublished())) . '"/>');
      }
 
      // Identifiers: DOI, URN
      foreach((array) $templateMgr->getTemplateVars('pubIdPlugins') as $pubIdPlugin) {
         if ($pubId = $submission->getStoredPubId($pubIdPlugin->getPubIdType())) {
            $templateMgr->addHeader('googleScholarPubId' . $pubIdPlugin->getPubIdDisplayType(), '<meta name="citation_' . htmlspecialchars(strtolower($pubIdPlugin->getPubIdDisplayType())) . '" content="' . htmlspecialchars($pubId) . '"/>');
         }
      }
 
      // Abstract url and keywords
      $templateMgr->addHeader('googleScholarHtmlUrl', '<meta name="citation_abstract_html_url" content="' . $request->url(null, $submissionPath, 'view', array($submission->getBestId())) . '"/>');
 
      $i=0;
      $dao = DAORegistry::getDAO('SubmissionKeywordDAO');
      $keywords = $dao->getKeywords($submission->getCurrentPublication()->getId(), array(AppLocale::getLocale()));
      foreach ($keywords as $locale => $localeKeywords) {
         foreach ($localeKeywords as $keyword) {
            $templateMgr->addHeader('googleScholarKeyword' . $i++, '<meta name="citation_keywords" xml:lang="' . htmlspecialchars(substr($locale, 0, 2)) . '" content="' . htmlspecialchars($keyword) . '"/>');
         }
      }
 
      // Galley links
      $i=$j=0;
      if (is_a($submission, 'Submission')) foreach ($submission->getGalleys() as $galley) {
         if (is_a($galley->getFile(), 'SupplementaryFile')) continue;
         if ($galley->getFileType()=='application/pdf') {
            $templateMgr->addHeader('googleScholarPdfUrl' . $i++, '<meta name="citation_pdf_url" content="' . $request->url(null, $submissionPath, 'download', array($submission->getBestId(), $galley->getBestGalleyId())) . '"/>');
         } elseif ($galley->getFileType()=='text/html') {
            $templateMgr->addHeader('googleScholarHtmlUrl' . $i++, '<meta name="citation_fulltext_html_url" content="' . $request->url(null, $submissionPath, 'view', array($submission->getBestId(), $galley->getBestGalleyId())) . '"/>');
         }
      }
 
      // Citations
      $outputReferences = array();
      $citationDao = DAORegistry::getDAO('CitationDAO'); /* @var $citationDao CitationDAO */
      $parsedCitations = $citationDao->getByPublicationId($submission->getCurrentPublication()->getId());
      if ($parsedCitations->getCount()){
         while ($citation = $parsedCitations->next()) {
            $outputReferences[] = $citation->getRawCitation();
         }
      }
      HookRegistry::call('GoogleScholarPlugin::references', array(&$outputReferences, $submission->getId()));
 
      if (!empty($outputReferences)){
         $i=0;
         foreach ($outputReferences as $outputReference) {
            $templateMgr->addHeader('googleScholarReference' . $i++, '<meta name="citation_reference" content="' . htmlspecialchars($outputReference) . '"/>');
         }
      }
 
      return false;
   }
 
   function getDisplayName() {
      return __('plugins.generic.googleScholar.name');
   }
 
   function getDescription() {
      return __('plugins.generic.googleScholar.description');
   }
}