KeywordCloudBlockPlugin.inc.php

<?php

/**
 * @file plugins/blocks/KeywordCloud/KeywordCloudBlockPlugin.inc.php
 *
 * Copyright (c) 2014-2018 Simon Fraser University
 * Copyright (c) 2003-2018 John Willinsky
 * Distributed under the GNU GPL v2. For full terms see the file docs/COPYING.
 *
 * @class KeywordCloudBlockPlugin
 * @ingroup plugins_blocks_Keywordcloud
 *
 * @brief Class for KeywordCloud block plugin
 */

define('KEYWORD_BLOCK_MAX_ITEMS', 100);
define('KEYWORD_BLOCK_CACHE_DAYS', 2);

import('lib.pkp.classes.plugins.BlockPlugin');

class KeywordCloudBlockPlugin extends BlockPlugin {
	/**
	 * Install default settings on journal creation.
	 * @return string
	 */
	function getContextSpecificPluginSettingsFile() {
		return $this->getPluginPath() . '/settings.xml';
	}

	/**
	 * Get the display name of this plugin.
	 * @return String
	 */
	function getDisplayName() {
		return __('plugins.block.keywordCloud.displayName');
	}

	/**
	 * Get a description of the plugin.
	 */
	function getDescription() {
		return __('plugins.block.keywordCloud.description');
	}

	/**
	 * @see BlockPlugin::getContents
	 */
	function getContents($templateMgr, $request = null) {
		$journal = $request->getJournal();
		if (!$journal) return '';
		
		$locale = AppLocale::getLocale();

		$cacheManager = CacheManager::getManager();
		$cache = $cacheManager->getFileCache(
			'keywords_'. $locale, $journal->getId(),
			array($this, '_cacheMiss')
		);

		$cacheTime = $cache->getCacheTime();
		if (time() - $cache->getCacheTime() > 60 * 60 * 24 * KEYWORD_BLOCK_CACHE_DAYS)
			$cache->flush();

		$keywords =& $cache->getContents();
		if (empty($keywords)) return '';
		
		$templateMgr->addJavaScript('d3','https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.17/d3.min.js');
		$templateMgr->addJavaScript('d3.layout.cloud','https://cdnjs.cloudflare.com/ajax/libs/d3-cloud/1.0.0/d3.layout.cloud.min.js');
		$templateMgr->addJavaScript('d3.wordcloud',$this->getJavaScriptURL($request).'d3.wordcloud.min.js');


		$templateMgr->assign('keywords', $keywords);
		return parent::getContents($templateMgr, $request);
	}
	
	function _cacheMiss($cache, $id) {

		//Get all published Articles of this Journal
		$publishedArticleDao = DAORegistry::getDAO('PublishedArticleDAO');
		$publishedArticles =& $publishedArticleDao->getPublishedArticlesByJournalId($cache->getCacheId(), $rangeInfo = null, $reverse = true);

		//Get all IDs of the published Articles
		$submissionKeywordDao = DAORegistry::getDAO('SubmissionKeywordDAO');
		//Get all Keywords from all published articles of this journal
		$all_keywords = array();
		while ($publishedArticle = $publishedArticles->next()) {
			$article_keywords = $submissionKeywordDao->getKeywords($publishedArticle->getId(),
				array(AppLocale::getLocale()))[AppLocale::getLocale()];
			$all_keywords = array_merge($all_keywords, $article_keywords);
		}

		//Count the keywords					
		$count_keywords = array_count_values($all_keywords);

		//Sort the keywords frequency-based
		arsort($count_keywords, SORT_NUMERIC);

		// Put only the most often used keywords in an array
		// maximum of KEYWORD_BLOCK_MAX_ITEMS
		$top_keywords = array_slice($count_keywords, 0, KEYWORD_BLOCK_MAX_ITEMS);
		
		$keywords = array();

		foreach ($top_keywords as $k => $c) {
			$kw = new stdClass();
			$kw->text = $k;
			$kw->size = $c;
			$keywords[] = $kw;
		}
		
		$cache->setEntireCache(json_encode($keywords));

		return null;
	}
	
	function getJavaScriptURL($request) {
		return $request->getBaseUrl() . '/' . $this->getPluginPath() . '/js/';
	}
}

?>