refs #19118 [fid_bbi] blog integration via rss feed

* add real blog-entries
** includes latest blog entries via Rss feed reader

* make Rss feed consumer more configurable, add caching
* improve excerpt shortening

fid_bbi/config/vufind/config.ini

@@ -93,6 +93,20 @@ host            = https://fid-bbi.idm.oclc.org
 ; authentication requests in VuFind:
 ;disable_ticket_auth_logging = true
 
+[RssConsumer]
+base_url = "https://www.fid-bbi.de/wordpress/"
+xml_doc = "?feed=rss2"
+input_date_format = "D, j M Y G:i:s O"
+excerpt_length = 150
+; excerpt_suffix is the string added to excerpts to denote they were shortened
+excerpt_suffix = " ..."
+limit = 4
+; set cache_ttl to
+; * number of seconds for cache lifetime
+; * or 0 for infinite caching (default)
+; * or -1 for no caching
+cache_ttl = 3600 ;one hour
+
 [Content]
 coversize = false
 

module/fid_bbi/config/module.config.php

@@ -23,6 +23,7 @@
 
 use VuFind\Db\Table\Tags as BaseTagsTable;
 use fid_bbi\Db\Table\Tags as BBITagsTable;
+use fid_bbi\Helper\Rss;
 use VuFind\Db\Row\Tags as BaseTagsRow;
 use VuFind\Db\Table\CaseSensitiveTagsFactory;
 use fid_bbi\Controller\RecordController;
@@ -84,6 +85,14 @@ $config = [
             ],
         ],
     ],
+    'view_helpers' => [
+        'aliases'   => [
+            'rss' => Rss::class,
+        ],
+        'factories' => [
+            Rss::class => 'fid_bbi\Helper\Factory::getRss',
+        ],
+    ],
     'vufind'      => [
         'plugin_managers'              => [
             'recorddriver' => [

module/fid_bbi/src/fid_bbi/Helper/Factory.php

+<?php
+/**
+ * Factory for view helpers.
+ *
+ * PHP version 7
+ *
+ * Copyright (C) Leipzig University Library 2021.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2,
+ * as published by the Free Software Foundation.
+ *
+ * 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * @category VuFind
+ * @package  View_Helpers
+ * @author   Dorain Merz <merz@ub.uni-leipzig.de>
+ * @license  http://opensource.org/licenses/gpl-2.0.php GNU General Public License
+ * @link     https://vufind.org/wiki/development Wiki
+ */
+namespace fid_bbi\Helper;
+
+use Interop\Container\ContainerInterface;
+
+/**
+ * Factory for Root view helpers.
+ *
+ * @category VuFind
+ * @package  View_Helpers
+ * @author   Dorain Merz <merz@ub.uni-leipzig.de>
+ * @license  http://opensource.org/licenses/gpl-2.0.php GNU General Public License
+ * @link     https://vufind.org/wiki/development Wiki
+ */
+class Factory
+{
+    /**
+     * Construct the Rss helper.
+     *
+     * @param ContainerInterface $container Service manager.
+     *
+     * @return Rss
+     */
+    public static function getRss(ContainerInterface $container)
+    {
+        return new Rss(
+            $container->get('VuFind\Config')->get('config')->RssConsumer,
+            $container->get('VuFind\Date\Converter'),
+            $container->get('VuFind\Cache\Manager')->getCache('object',Rss::class)
+        );
+    }
+}

module/fid_bbi/src/fid_bbi/Helper/Rss.php

+<?php
+/**
+ * Copyright (C) 2019 Leipzig University Library
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * @author   Robert Lange <lange@ub.uni-leipzig.de>
+ * @author   Dorian Merz <merz@ub.uni-leipzig.de>
+ * @license  http://opensource.org/licenses/gpl-2.0.php GNU GPLv2
+ */
+
+namespace fid_bbi\Helper;
+
+use DOMDocument;
+use VuFind\Date\Converter;
+use Zend\Cache\Storage\StorageInterface;
+use Zend\Config\Config;
+use Zend\View\Helper\AbstractHelper;
+
+/**
+ * Class Rss Provides feed reader functionality
+ * Mostly a copy from instance/fid_adlr,
+ * * adds excerpt and date,
+ * * returns objects instead of arrays
+ * * provides __invoke
+ * * alters constructor to include config and dateConverter
+ *
+ * @deprecated pull up to FID-module
+ * @package fid_bbi\Helper
+ */
+class Rss extends AbstractHelper
+{
+    /**
+     * @var Config
+     */
+    protected $rssConfig;
+
+    /**
+     * @var Converter
+     */
+    protected $dateConverter;
+
+    /**
+     * @var StorageInterface
+     */
+    protected $cache;
+
+    /**
+     * @var bool
+     */
+    protected $caching;
+
+    /**
+     * @var string
+     */
+    protected $cacheKey;
+
+    /**
+     * Rss constructor.
+     * @param Config $rssConfig
+     * @param Converter $dateConverter
+     * @param StorageInterface $cacheManager
+     */
+    public function __construct(Config $rssConfig, Converter $dateConverter, StorageInterface $cache)
+    {
+        $this->rssConfig = $rssConfig;
+        $this->dateConverter = $dateConverter;
+        $this->feedDateFormat = $this->rssConfig->input_date_format ?? 'c';
+        $this->prepareCache($cache);
+    }
+
+    protected function prepareCache(StorageInterface $cache)
+    {
+        $ttl = $this->rssConfig['cache_ttl'] ?? 0;
+        if ($ttl == -1) {
+            $this->caching = false;
+        } else {
+            $this->caching = true;
+            $this->cache = $cache;
+            $this->cache->getOptions()->setTtl($ttl);
+            $this->cacheKey = md5(implode($this->rssConfig->toArray()));
+        }
+    }
+
+    /**
+     * Read cached feed
+     *
+     * @return bool|mixed cached feed or false if caching is inactive
+     */
+    protected function readCacheData()
+    {
+        if ($this->caching) {
+            return $this->cache->getItem($this->cacheKey);
+        }
+        return false;
+    }
+
+    protected function writeCacheData($data)
+    {
+        if ($this->caching) {
+            $this->cache->setItem($this->cacheKey,$data);
+        }
+    }
+
+    /**
+     * Read the feed
+     *
+     * @return array|bool|mixed
+     */
+    public function __invoke()
+    {
+        return $this->getFeed();
+    }
+
+    /**
+     * get Rss feed data
+     *
+     * @return array|bool|mixed
+     */
+    protected function getFeed()
+    {
+        if ($cacheData = $this->readCacheData()) {
+            return $cacheData;
+        } else {
+            $feed = $this->load($this->rssConfig);
+            $this->writeCacheData($feed);
+            return $feed;
+        }
+    }
+
+    /**
+     * @param array of rss origin data
+     * @return array of rss feeds
+     */
+    public function load($rssOrigin)
+    {
+        $baseUrl    = $rssOrigin["base_url"] ?? "";
+        $fallback   = $rssOrigin["fallback_url"] ?? "";
+        $docPath    = $rssOrigin["xml_doc"] ?? "";
+
+        $rssDoc = new DOMDocument();
+        $feeds = array();
+        try {
+            if ($rssDoc->load($baseUrl . '/' . $docPath)) {
+                $limit = $rssOrigin['limit'] ?? 3;
+                $n = 0;
+
+                foreach ($rssDoc->getElementsByTagName('item') as $node) {
+                    $excerpt = $node->getElementsByTagName('description')->item(0)->nodeValue;
+                    if (strlen($excerpt) > $this->rssConfig->excerpt_length) {
+                        $excerpt = substr($excerpt, 0, $this->rssConfig->excerpt_length);
+                        $lastSpace = strrpos($excerpt, ' ');
+                        $excerpt = substr($excerpt, 0, $lastSpace);
+                        if (isset($this->rssConfig['excerpt_suffix'])) {
+                            $excerpt .= $this->rssConfig['excerpt_suffix'];
+                        }
+                    }
+                    $date = $node->getElementsByTagName('pubDate')->item(0)->nodeValue;
+                    $date = $this->dateConverter->convertToDisplayDate($this->feedDateFormat,$date);
+                    $item = array(
+                        'title' => $node->getElementsByTagName('title')->item(0)->nodeValue,
+                        'link' => $node->getElementsByTagName('link')->item(0)->nodeValue,
+                        'excerpt' => $excerpt,
+                        'date' => $date,
+                    );
+                    array_push($feeds, (object)$item);
+
+                    if (++$n >= $limit) {
+                        break;
+                    }
+                }
+            }
+        } catch (\Exception $ex) {
+            if ($fallback) {
+                $item = array(
+                    'title' => $fallback,
+                    'link' => $fallback
+                );
+                array_push($feeds, $item);
+            }
+        }
+
+        return $feeds;
+    }
+}

themes/fid_bbi/templates/search/home.phtml

@@ -11,13 +11,9 @@ $this->layout()->breadcrumbs = false;
     <h2 class="sr-only"><?=$this->translate('Recent Blog Posts')?></h2>
 
     <div class="posts">
-      <?php
-      // TODO: Replace this once blog API is available
-      $postsFile = APPLICATION_PATH . '/themes/fid_bbi/dummy-posts.json';
-      $posts = @json_decode(@file_get_contents($postsFile));
-      ?>
-
-      <?php if ($posts): ?>
+        <?php
+        $posts = $this->rss();
+    if ($posts): ?>
         <?php foreach ($posts as $post): ?>
           <article class="post">
             <header class="post_header">