Add collections and authors RSS/Atom/OPDS feeds

.gitignore

@@ -2,11 +2,11 @@ ebooks/*
 www/ebooks/*
 www/images/covers/*
 www/feeds/opds/*.xml
-www/feeds/opds/subjects/*.xml
+www/feeds/opds/*/*.xml
 www/feeds/rss/*.xml
-www/feeds/rss/subjects/*.xml
+www/feeds/rss/*/*.xml
 www/feeds/atom/*.xml
-www/feeds/atom/subjects/*.xml
+www/feeds/atom/*/*.xml
 vendor/
 composer.lock
 .vagrant/

config/apache/standardebooks.org.conf

@@ -279,6 +279,8 @@ Define webroot /standardebooks.org/web
 	RewriteCond %{QUERY_STRING}		\bquery=
 	RewriteRule				^/feeds/(opds|atom|rss)/all.xml$		/feeds/$1/search.php [QSA]
 
+	RewriteRule				^/feeds/(atom|rss)/([^/\.]+)$			/feeds/collection.php?type=$1&name=$2
+
 	# Rewrite rules for bulk downloads
 	RewriteRule 				^/bulk-downloads/(.+\.zip)$			/bulk-downloads/download.php?path=$1
 	RewriteRule 				^/bulk-downloads/([^/\.]+)$			/bulk-downloads/collection.php?name=$1

config/apache/standardebooks.test.conf

@@ -261,6 +261,8 @@ Define webroot /standardebooks.org/web
 	RewriteCond %{QUERY_STRING}		\bquery=
 	RewriteRule				^/feeds/(opds|atom|rss)/all.xml$		/feeds/$1/search.php [QSA]
 
+	RewriteRule				^/feeds/(atom|rss)/([^/\.]+)$			/feeds/collection.php?type=$1&name=$2
+
 	# Rewrite rules for bulk downloads
 	RewriteRule 				^/bulk-downloads/(.+\.zip)$			/bulk-downloads/download.php?path=$1
 	RewriteRule 				^/bulk-downloads/([^/\.]+)$			/bulk-downloads/collection.php?name=$1

lib/AtomFeed.php

@@ -23,7 +23,7 @@ class AtomFeed extends Feed{
 		parent::__construct($title, $url, $path, $entries);
 		$this->Subtitle = $subtitle;
 		$this->Id = $url;
-		$this->Stylesheet = '/feeds/atom/style';
+		$this->Stylesheet = SITE_URL . '/feeds/atom/style';
 	}
 
 
@@ -41,13 +41,16 @@ class AtomFeed extends Feed{
 		return $this->XmlString;
 	}
 
-	public function SaveIfChanged(): void{
+	public function SaveIfChanged(): bool{
 		// Did we actually update the feed? If so, write to file and update the index
 		if($this->HasChanged($this->Path)){
 			// Files don't match, save the file
 			$this->Updated = new DateTime();
 			$this->Save();
+			return true;
 		}
+
+		return false;
 	}
 
 	protected function HasChanged(string $path): bool{

lib/Library.php

@@ -322,7 +322,10 @@ class Library{
 	 * @return array<string, array<int|string, array<int|string, mixed>>>
 	 */
 	public static function RebuildBulkDownloadsCache(): array{
-		$collator = collator_create( 'en_US' ); // Used for sorting letters with diacritics like in author names
+		$collator = Collator::create('en_US'); // Used for sorting letters with diacritics like in author names
+		if($collator === null){
+			throw new Exceptions\SeException('Couldn\'t create collator object when rebuilding bulk download cache.');
+		}
 		$months = [];
 		$subjects = [];
 		$collections = [];

lib/OpdsFeed.php

@@ -16,7 +16,7 @@ class OpdsFeed extends AtomFeed{
 	public function __construct(string $title, string $subtitle, string $url, string $path, array $entries, ?OpdsNavigationFeed $parent){
 		parent::__construct($title, $subtitle, $url, $path, $entries);
 		$this->Parent = $parent;
-		$this->Stylesheet = '/feeds/opds/style';
+		$this->Stylesheet = SITE_URL . '/feeds/opds/style';
 	}
 
 
@@ -45,7 +45,7 @@ class OpdsFeed extends AtomFeed{
 		}
 	}
 
-	public function SaveIfChanged(): void{
+	public function SaveIfChanged(): bool{
 		// Did we actually update the feed? If so, write to file and update the index
 		if($this->HasChanged($this->Path)){
 			// Files don't match, save the file and update the parent navigation feed with the last updated timestamp
@@ -58,6 +58,9 @@ class OpdsFeed extends AtomFeed{
 
 			// Save our own file
 			$this->Save();
+			return true;
 		}
+
+		return false;
 	}
 }

lib/RssFeed.php

@@ -17,7 +17,7 @@ class RssFeed extends Feed{
 	public function __construct(string $title, string $description, string $url, string $path, array $entries){
 		parent::__construct($title, $url, $path, $entries);
 		$this->Description = $description;
-		$this->Stylesheet = '/feeds/rss/style';
+		$this->Stylesheet = SITE_URL . '/feeds/rss/style';
 	}
 
 
@@ -35,12 +35,15 @@ class RssFeed extends Feed{
 		return $this->XmlString;
 	}
 
-	public function SaveIfChanged(): void{
+	public function SaveIfChanged(): bool{
 		// Did we actually update the feed? If so, write to file and update the index
 		if($this->HasChanged($this->Path)){
 			// Files don't match, save the file
 			$this->Save();
+			return true;
 		}
+
+		return false;
 	}
 
 	protected function HasChanged(string $path): bool{

scripts/generate-feeds

@@ -2,24 +2,58 @@
 <?
 require_once('/standardebooks.org/web/lib/Core.php');
 
-use function Safe\krsort;
+use Safe\DateTime;
 use function Safe\getopt;
 use function Safe\mkdir;
 use function Safe\preg_replace;
-use function Safe\sort;
 
-function SaveFeed($feed, $force, $now = null){
+function SortByUpdatedDesc($a, $b){
+	return $b->Updated <=> $a->Updated;
+}
+
+function SaveFeed(Feed $feed, bool $force, ?string $label = null, ?string $labelSort = null, DateTime $now = null): void{
+	$updateAttrs = false;
+
 	if($force){
 		if($now !== null){
 			$feed->Updated = $now;
 		}
 		$feed->Save();
+		$updateAttrs = true;
 	}
 	else{
-		$feed->SaveIfChanged();
+		$updateAttrs = $feed->SaveIfChanged();
+	}
+
+	if($updateAttrs && $label !== null && $labelSort !== null){
+		exec('attr -q -s se-label -V ' . escapeshellarg($label) . ' ' . escapeshellarg($feed->Path));
+		exec('attr -q -s se-label-sort -V ' . escapeshellarg($labelSort) . ' ' . escapeshellarg($feed->Path));
 	}
 }
 
+function CreateOpdsCollectionFeed(string $name, string $url, string $description, array $collections, array $ebooks, DateTime $now, string $webRoot, OpdsNavigationFeed $opdsRoot, bool $force): void{
+	$collator = collator_create('en_US'); // Used for sorting letters with diacritics like in author names
+	usort($collections, function($a, $b) use($collator){ return $collator->compare($a['sortedname'], $b['sortedname']); });
+
+	// Create the collections navigation document
+	$collectionNavigationEntries = [];
+	foreach($collections as $collection){
+		$collectionNavigationEntries[] = new OpdsNavigationEntry($collection['name'], str_replace('%s', $collection['name'], $description), $url . '/' . $collection['id'], $now, 'subsection', 'navigation');
+	}
+	$collectionsFeed = new OpdsNavigationFeed('Standard Ebooks by ' . ucfirst($name), 'Browse Standard Ebooks by ' . $name . '.', $url, $webRoot . $url . '/index.xml', $collectionNavigationEntries, $opdsRoot);
+	$collectionsFeed->Subtitle = 'Browse Standard Ebooks by collection.';
+	SaveFeed($collectionsFeed, $force, null, null, $now);
+
+	// Now generate each individual collection feed
+	foreach($collectionNavigationEntries as $collectionNavigationEntry){
+		$id = basename($collectionNavigationEntry->Id);
+		usort($ebooks[$id], 'SortByUpdatedDesc');
+		$collectionFeed = new OpdsAcquisitionFeed($collectionNavigationEntry->Title . ' Ebooks', $collectionNavigationEntry->Description, $url . '/' . $id, $webRoot . $url . '/' . $id . '.xml', $ebooks[$id], $collectionsFeed);
+		SaveFeed($collectionFeed, $force, null, null, $now);
+	}
+}
+
+
 $longopts = ['webroot:', 'force'];
 $options = getopt('', $longopts);
 $webRoot = $options['webroot'] ?? WEB_ROOT;
@@ -29,37 +63,47 @@ $allEbooks = [];
 $newestEbooks = [];
 $subjects = [];
 $ebooksBySubject = [];
+$collections = [];
+$ebooksByCollection = [];
+$authors = [];
+$ebooksByAuthor = [];
 $ebooksPerNewestEbooksFeed = 15;
 
-if(!is_dir($webRoot . '/feeds/opds/subjects')){
+$dirs = [	'/feeds/opds/subjects', '/feeds/rss/subjects', '/feeds/atom/subjects',
-	mkdir($webRoot . '/feeds/opds/subjects');
+		'/feeds/opds/collections', '/feeds/rss/collections', '/feeds/atom/collections',
-}
+		'/feeds/opds/authors', '/feeds/rss/authors', '/feeds/atom/authors'
+	];
 
-if(!is_dir($webRoot . '/feeds/rss/subjects')){
+foreach($dirs as $dir){
-	mkdir($webRoot . '/feeds/rss/subjects');
+	if(!is_dir($webRoot . $dir)){
-}
+		mkdir($webRoot . $dir);
-
+	}
-if(!is_dir($webRoot . '/feeds/atom/subjects')){
-	mkdir($webRoot . '/feeds/atom/subjects');
 }
 
 // Iterate over all ebooks to build the various feeds
 foreach(Library::GetEbooksFromFilesystem($webRoot) as $ebook){
-	$allEbooks[$ebook->Updated->format('Y-m-d\TH:i:s\Z') . ' ' . $ebook->Identifier] = $ebook;
+	$allEbooks[] = $ebook;
-	$newestEbooks[$ebook->Created->format('Y-m-d\TH:i:s\Z') . ' ' . $ebook->Identifier] = $ebook;
+	$newestEbooks[] = $ebook;
 
 	foreach($ebook->Tags as $tag){
-		// Add the book's subjects to the main subjects list
+		$urlName = Formatter::MakeUrlSafe($tag->Name);
-		if(!in_array($tag->Name, $subjects)){
+		$ebooksBySubject[$urlName][] = $ebook;
-			$subjects[] = $tag->Name;
+		$subjects[$urlName] = ['id' => $urlName, 'name' => $tag->Name, 'sortedname' => $tag->Name];
 	}
 
-		// Sort this ebook by subject
+	foreach($ebook->Collections as $collection){
-		$ebooksBySubject[$tag->Name][$ebook->Created->format('Y-m-d\TH:i:s\Z') . ' ' . $ebook->Identifier] = $ebook;
+		$urlName = Formatter::MakeUrlSafe($collection->Name);
+		$ebooksByCollection[$urlName][] = $ebook;
+		$collections[$urlName] = ['id' => $urlName, 'name' => $collection->Name, 'sortedname' => $collection->GetSortedName()];
 	}
+
+	$authorsUrl = preg_replace('|^/ebooks/|', '', $ebook->AuthorsUrl);
+	$ebooksByAuthor[$authorsUrl][] = $ebook;
+	$authors[$authorsUrl] = ['id' => $authorsUrl, 'name' => strip_tags($ebook->AuthorsHtml), 'sortedname' => $ebook->Authors[0]->SortName];
 }
 
-krsort($newestEbooks);
+usort($allEbooks, 'SortByUpdatedDesc');
+usort($newestEbooks, function($a, $b){ return $b->Created <=> $a->Created; });
 $newestEbooks = array_slice($newestEbooks, 0, $ebooksPerNewestEbooksFeed);
 
 $now = new DateTime();
@@ -81,6 +125,20 @@ $opdsRootEntries = [
 		$now,
 		'subsection',
 		'navigation'),
+	new OpdsNavigationEntry(
+		'Standard Ebooks by Collection',
+		'Browse Standard Ebooks by collection.',
+		'/feeds/opds/collections',
+		$now,
+		'subsection',
+		'navigation'),
+	new OpdsNavigationEntry(
+		'Standard Ebooks by Author',
+		'Browse Standard Ebooks by author.',
+		'/feeds/opds/authors',
+		$now,
+		'subsection',
+		'navigation'),
 	new OpdsNavigationEntry(
 		'All Standard Ebooks',
 		'All Standard Ebooks, most-recently-updated first. This is a Complete Acquisition Feed as defined in OPDS 1.2 §2.5.',
@@ -91,64 +149,85 @@ $opdsRootEntries = [
 ];
 
 $opdsRoot = new OpdsNavigationFeed('Standard Ebooks', 'The Standard Ebooks catalog.', '/feeds/opds', $webRoot . '/feeds/opds/index.xml', $opdsRootEntries, null);
-SaveFeed($opdsRoot, $force, $now);
+SaveFeed($opdsRoot, $force, null, null, $now);
 
-// Create the subjects navigation document
+// Create the Subjects feeds
-sort($subjects);
+CreateOpdsCollectionFeed('subject', '/feeds/opds/subjects', 'Standard Ebooks in the “%s” subject, most-recently-released first.', $subjects, $ebooksBySubject, $now, $webRoot, $opdsRoot, $force);
-$subjectNavigationEntries = [];
-foreach($subjects as $subject){
-	$subjectNavigationEntries[] = new OpdsNavigationEntry($subject, 'Standard Ebooks tagged with “' . strtolower($subject) . ',” most-recently-released first.', '/feeds/opds/subjects/' . Formatter::MakeUrlSafe($subject), $now, 'subsection', 'navigation');
-}
-$subjectsFeed = new OpdsNavigationFeed('Standard Ebooks by Subject', 'Browse Standard Ebooks by subject.', '/feeds/opds/subjects', $webRoot . '/feeds/opds/subjects/index.xml', $subjectNavigationEntries, $opdsRoot);
-$subjectsFeed->Subtitle = 'Browse Standard Ebooks by subject.';
-SaveFeed($subjectsFeed, $force, $now);
 
-// Now generate each individual subject feed
+// Create the Collections feeds
-foreach($subjectNavigationEntries as $subjectNavigationEntry){
+CreateOpdsCollectionFeed('collection', '/feeds/opds/collections', 'Standard Ebooks in the “%s” collection, most-recently-released first.', $collections, $ebooksByCollection, $now, $webRoot, $opdsRoot, $force);
-	krsort($ebooksBySubject[$subjectNavigationEntry->Title]);
-	$subjectFeed = new OpdsAcquisitionFeed($subjectNavigationEntry->Title . ' Ebooks', $subjectNavigationEntry->Description, '/feeds/opds/subjects/' . Formatter::MakeUrlSafe($subjectNavigationEntry->Title), $webRoot . '/feeds/opds/subjects/' . Formatter::MakeUrlSafe($subjectNavigationEntry->Title) . '.xml', $ebooksBySubject[$subjectNavigationEntry->Title], $subjectsFeed);
-	SaveFeed($subjectFeed, $force, $now);
-}
 
-// Create the 'all' feed
+// Create the Author feeds
-krsort($allEbooks);
+CreateOpdsCollectionFeed('author', '/feeds/opds/authors', 'Standard Ebooks by %s, most-recently-released first.', $authors, $ebooksByAuthor, $now, $webRoot, $opdsRoot, $force);
+
+// Create the All feed
 $allFeed = new OpdsAcquisitionFeed('All Standard Ebooks', 'All Standard Ebooks, most-recently-updated first. This is a Complete Acquisition Feed as defined in OPDS 1.2 §2.5.', '/feeds/opds/all', $webRoot . '/feeds/opds/all.xml', $allEbooks, $opdsRoot, true);
-SaveFeed($allFeed, $force, $now);
+SaveFeed($allFeed, $force, null, null, $now);
 
-// Create the 'newest' feed
+// Create the Newest feed
 $newestFeed = new OpdsAcquisitionFeed('Newest Standard Ebooks', 'The ' . number_format($ebooksPerNewestEbooksFeed) . ' latest Standard Ebooks, most-recently-released first.', '/feeds/opds/new-releases', $webRoot . '/feeds/opds/new-releases.xml', $newestEbooks, $opdsRoot);
-SaveFeed($newestFeed, $force, $now);
+SaveFeed($newestFeed, $force, null, null, $now);
 
-// Now create RSS feeds
 
-// Create the 'newest' feed
-$newestRssFeed = new RssFeed('Standard Ebooks - Newest Ebooks', 'The ' . number_format($ebooksPerNewestEbooksFeed) . ' latest Standard Ebooks, most-recently-released first.', '/feeds/rss/new-releases', $webRoot . '/feeds/rss/new-releases.xml', $newestEbooks);
-SaveFeed($newestRssFeed, $force);
 
-// Create the 'all' feed
+// Create RSS/Atom feeds
+
+// Create the RSS All feed
 $allRssFeed = new RssFeed('Standard Ebooks - All Ebooks', 'All Standard Ebooks, most-recently-released first.', '/feeds/rss/all',  $webRoot . '/feeds/rss/all.xml', $allEbooks);
-SaveFeed($allRssFeed, $force);
+SaveFeed($allRssFeed, $force, null, null);
 
-// Generate each individual subject feed
+// Create the RSS Newest feed
-foreach($ebooksBySubject as $subject => $ebooks){
+$newestRssFeed = new RssFeed('Standard Ebooks - Newest Ebooks', 'The ' . number_format($ebooksPerNewestEbooksFeed) . ' latest Standard Ebooks, most-recently-released first.', '/feeds/rss/new-releases', $webRoot . '/feeds/rss/new-releases.xml', $newestEbooks);
-	krsort($ebooks);
+SaveFeed($newestRssFeed, $force, null, null);
-	$subjectRssFeed = new RssFeed('Standard Ebooks - ' . (string)$subject . ' Ebooks', 'Standard Ebooks tagged with “' . strtolower($subject) . ',” most-recently-released first.', '/feeds/rss/subjects/' . Formatter::MakeUrlSafe((string)$subject),  $webRoot . '/feeds/rss/subjects/' . Formatter::MakeUrlSafe((string)$subject) . '.xml', $ebooks);
-	SaveFeed($subjectRssFeed, $force);
-}
 
-// Now create the Atom feeds
+// Create the Atom All feed
-// Create the 'newest' feed
-$newestAtomFeed = new AtomFeed('Standard Ebooks - Newest Ebooks', 'The ' . number_format($ebooksPerNewestEbooksFeed) . ' latest Standard Ebooks, most-recently-released first.', '/feeds/atom/new-releases', $webRoot . '/feeds/atom/new-releases.xml', $newestEbooks);
-SaveFeed($newestAtomFeed, $force, $now);
-
-// Create the 'all' feed
 $allAtomFeed = new AtomFeed('Standard Ebooks - All Ebooks', 'All Standard Ebooks, most-recently-released first.', '/feeds/atom/all',  $webRoot . '/feeds/atom/all.xml', $allEbooks);
-SaveFeed($allAtomFeed, $force, $now);
+SaveFeed($allAtomFeed, $force, null, null, $now);
+
+// Create the Atom Newest feed
+$newestAtomFeed = new AtomFeed('Standard Ebooks - Newest Ebooks', 'The ' . number_format($ebooksPerNewestEbooksFeed) . ' latest Standard Ebooks, most-recently-released first.', '/feeds/atom/new-releases', $webRoot . '/feeds/atom/new-releases.xml', $newestEbooks);
+SaveFeed($newestAtomFeed, $force, null, null, $now);
 
 // Generate each individual subject feed
 foreach($ebooksBySubject as $subject => $ebooks){
-	krsort($ebooks);
+	usort($ebooks, 'SortByUpdatedDesc');
-	$subjectAtomFeed = new AtomFeed('Standard Ebooks - ' . (string)$subject . ' Ebooks', 'Standard Ebooks tagged with “' . strtolower($subject) . ',” most-recently-released first.', '/feeds/atom/subjects/' . Formatter::MakeUrlSafe((string)$subject),  $webRoot . '/feeds/atom/subjects/' . Formatter::MakeUrlSafe((string)$subject) . '.xml', $ebooks);
+
-	SaveFeed($subjectAtomFeed, $force, $now);
+	$title = 'Standard Ebooks - ' . $subjects[$subject]['name'] . ' Ebooks';
+	$subtitle = 'Standard Ebooks in the “' . strtolower($subjects[$subject]['name']) . '” subject, most-recently-released first.';
+
+	$subjectRssFeed = new RssFeed($title, $subtitle, '/feeds/rss/subjects/' . Formatter::MakeUrlSafe($subject),  $webRoot . '/feeds/rss/subjects/' . Formatter::MakeUrlSafe($subject) . '.xml', $ebooks);
+	SaveFeed($subjectRssFeed, $force, $subjects[$subject]['name'], $subjects[$subject]['sortedname']);
+
+	$subjectAtomFeed = new AtomFeed($title, $subtitle, '/feeds/atom/subjects/' . Formatter::MakeUrlSafe($subject),  $webRoot . '/feeds/atom/subjects/' . Formatter::MakeUrlSafe($subject) . '.xml', $ebooks);
+	SaveFeed($subjectAtomFeed, $force, $subjects[$subject]['name'], $subjects[$subject]['sortedname'], $now);
+}
+
+// Generate each individual collection feed
+foreach($ebooksByCollection as $collection => $ebooks){
+	usort($ebooks, 'SortByUpdatedDesc');
+
+	$titleName = preg_replace('/^The /ius', '', $collections[$collection]['name']);
+
+	$title ='Standard Ebooks - Ebooks in the ' . $titleName . ' collection';
+	$subtitle = 'Standard Ebooks in the ' . $titleName . ' collection, most-recently-released first.';
+
+	$collectionRssFeed = new RssFeed($title, $subtitle, '/feeds/rss/collections/' . Formatter::MakeUrlSafe($collection),  $webRoot . '/feeds/rss/collections/' . Formatter::MakeUrlSafe($collection) . '.xml', $ebooks);
+	SaveFeed($collectionRssFeed, $force, $collections[$collection]['name'], $collections[$collection]['sortedname']);
+
+	$collectionAtomFeed = new AtomFeed($title, $subtitle, '/feeds/atom/collections/' . Formatter::MakeUrlSafe($collection),  $webRoot . '/feeds/atom/collections/' . Formatter::MakeUrlSafe($collection) . '.xml', $ebooks);
+	SaveFeed($collectionAtomFeed, $force, $collections[$collection]['name'], $collections[$collection]['sortedname'], $now);
+}
+
+// Generate each individual author feed
+foreach($ebooksByAuthor as $collection => $ebooks){
+	usort($ebooks, 'SortByUpdatedDesc');
+
+	$title = 'Standard Ebooks - Ebooks by ' . $authors[$collection]['name'];
+	$subtitle = 'Standard Ebooks by ' . $authors[$collection]['name'] . ', most-recently-released first.';
+
+	$collectionRssFeed = new RssFeed($title, $subtitle, '/feeds/rss/authors/' . $authors[$collection]['id'],  $webRoot . '/feeds/rss/authors/' . $authors[$collection]['id'] . '.xml', $ebooks);
+	SaveFeed($collectionRssFeed, $force, $authors[$collection]['name'], $authors[$collection]['sortedname']);
+
+	$collectionAtomFeed = new AtomFeed($title, $subtitle, '/feeds/atom/authors/' . $authors[$collection]['id'],  $webRoot . '/feeds/atom/authors/' . $authors[$collection]['id'] . '.xml', $ebooks);
+	SaveFeed($collectionAtomFeed, $force, $authors[$collection]['name'], $authors[$collection]['sortedname'], $now);
 }
-?>

templates/FeedHowTo.php

@@ -2,6 +2,7 @@
 	<h2>Accessing the feeds</h2>
 	<p>Our New Releases feeds are accessible by the public. Access to our other, more detailed feeds is available to our <a href="/about#patrons-circle">Patrons Circle supporters</a> and our <a href="/about#corporate-sponsors">corporate sponsors</a>.</p>
 	<p><i>If you’re a Patrons Circle member, when prompted enter your email address and leave the password field blank to access a feed.</i></p>
+	<? if($GLOBALS['User'] === null){ ?>
 	<section id="individuals">
 		<h3>Access for individuals</h3>
 		<ul>
@@ -16,4 +17,5 @@
 			<li><p>Software projects that are open-source and not-for-profit may be granted free access to our feeds. <a href="/about#editor-in-chief">Contact us</a> to inquire.</p></li>
 		</ul>
 	</section>
+	<? } ?>
 </section>

www/bulk-downloads/collection.php

@@ -8,7 +8,7 @@ $canDownload = false;
 $name = HttpInput::Str(GET, 'name', false) ?? '';
 
 if($name != 'authors' && $name != 'collections' && $name != 'subjects' && $name != 'months'){
-	$name = 'subjects';
+	Template::Emit404();
 }
 
 if($GLOBALS['User'] !== null && $GLOBALS['User']->Benefits->CanBulkDownload){

www/feeds/atom/index.php

@@ -17,21 +17,24 @@ require_once('Core.php');
 					<p>The fifteen latest Standard Ebooks, most-recently-released first.</p>
 				</li>
 				<li>
-					<p><a href="/feeds/atom/all">All ebooks</a></p>
+					<p><a href="<? if($GLOBALS['User'] !== null){ ?>https://<?= rawurlencode($GLOBALS['User']->Email) ?>@<?= SITE_DOMAIN ?><? } ?>/feeds/atom/all">All ebooks</a></p>
-					<p class="url"><?= SITE_URL ?>/feeds/atom/all</p>
+					<p class="url"><? if($GLOBALS['User'] !== null){ ?>https://<?= rawurlencode($GLOBALS['User']->Email) ?>@<?= SITE_DOMAIN ?><? }else{ ?><?= SITE_URL ?><? } ?>/feeds/atom/all</p>
 					<p>All Standard Ebooks, most-recently-released first.</p>
 				</li>
 			</ul>
 		</section>
-		<section id="ebooks-by-subject">
+		<section id="feeds-by-topic">
-			<h2>Ebooks by subject</h2>
+			<h2>Feeds by topic</h2>
 			<ul class="feed">
-				<? foreach(SE_SUBJECTS as $subject){ ?>
 				<li>
-					<p><a href="/feeds/atom/subjects/<?= Formatter::MakeUrlSafe($subject) ?>"><?= Formatter::ToPlainText($subject) ?></a></p>
+					<p><a href="/feeds/atom/authors">Feeds by author</a></p>
-					<p class="url"><?= SITE_URL ?>/feeds/atom/subjects/<?= Formatter::MakeUrlSafe($subject) ?></p>
+				</li>
+				<li>
+					<p><a href="/feeds/atom/collections">Feeds by collection</a></p>
+				</li>
+				<li>
+					<p><a href="/feeds/atom/subjects">Feeds by subject</a></p>
 				</li>
-				<? } ?>
 			</ul>
 		</section>
 	</section>

www/feeds/atom/search.php

@@ -16,7 +16,7 @@ catch(\Exception $ex){
 	include(WEB_ROOT . '/404.php');
 	exit();
 }
-print("<?xml version=\"1.0\" encoding=\"utf-8\"?>\n<?xml-stylesheet href=\"/feeds/atom/style\" type=\"text/xsl\"?>\n");
+print("<?xml version=\"1.0\" encoding=\"utf-8\"?>\n<?xml-stylesheet href=\"" . SITE_URL . "/feeds/atom/style\" type=\"text/xsl\"?>\n");
 ?>
 <feed xmlns="http://www.w3.org/2005/Atom" xmlns:media="http://search.yahoo.com/mrss/" xmlns:opensearch="http://a9.com/-/spec/opensearch/1.1/">
 	<id><?= SITE_URL ?>/feeds/atom/all?query=<?= urlencode($query) ?></id>

www/feeds/atom/subjects/index.php

@@ -1,22 +0,0 @@
-<?
-require_once('Core.php');
-
-?><?= Template::Header(['title' => 'Atom 1.0 Ebook Feeds by Subject', 'description' => 'A list of available Atom 1.0 feeds of Standard Ebooks ebooks by subject.']) ?>
-<main>
-	<article>
-		<h1>Atom 1.0 Ebook Feeds by Subject</h1>
-		<?= Template::FeedHowTo() ?>
-		<section id="ebooks-by-subject">
-			<h2>Ebooks by subject</h2>
-			<ul class="feed">
-				<? foreach(SE_SUBJECTS as $subject){ ?>
-				<li>
-					<p><a href="/feeds/atom/subjects/<?= Formatter::MakeUrlSafe($subject) ?>"><?= Formatter::ToPlainText($subject) ?></a></p>
-					<p class="url"><?= SITE_URL ?>/feeds/atom/subjects/<?= Formatter::MakeUrlSafe($subject) ?></p>
-				</li>
-				<? } ?>
-			</ul>
-		</section>
-	</article>
-</main>
-<?= Template::Footer() ?>

www/feeds/collection.php

@@ -0,0 +1,79 @@
+<?
+require_once('Core.php');
+
+use function Safe\apcu_fetch;
+use function Safe\glob;
+use function Safe\preg_replace;
+use function Safe\usort;
+
+$name = HttpInput::Str(GET, 'name', false) ?? '';
+$type = HttpInput::Str(GET, 'type', false) ?? '';
+
+if($name != 'authors' && $name != 'collections' && $name != 'subjects'){
+	Template::Emit404();
+}
+
+if($type != 'rss' && $type != 'atom'){
+	Template::Emit404();
+}
+
+$feeds = [];
+
+$lcTitle = preg_replace('/s$/', '', $name);
+$ucTitle = ucfirst($lcTitle);
+$ucType = 'RSS 2.0';
+if($type === 'atom'){
+	$ucType = 'Atom 1.0';
+}
+
+try{
+	$feeds = apcu_fetch('feeds-index-' . $type . '-' . $name);
+}
+catch(Safe\Exceptions\ApcuException $ex){
+	$files = glob(WEB_ROOT . '/feeds/' . $type . '/' . $name . '/*.xml');
+
+	$feeds = [];
+
+	foreach($files as $file){
+		$obj = new stdClass();
+		$obj->Url = '/feeds/' . $type . '/' . $name . '/' . basename($file, '.xml');
+
+		$obj->Label  = exec('attr -g se-label ' . escapeshellarg($file)) ?: null;
+		if($obj->Label == null){
+			$obj->Label = basename($file, '.xml');
+		}
+
+		$obj->LabelSort  = exec('attr -g se-label-sort ' . escapeshellarg($file)) ?: null;
+		if($obj->LabelSort == null){
+			$obj->LabelSort = basename($file, '.xml');
+		}
+
+		$feeds[] = $obj;
+	}
+
+	$collator = Collator::create('en_US'); // Used for sorting letters with diacritics like in author names
+	if($collator !== null){
+		usort($feeds, function($a, $b) use($collator){ return $collator->compare($a->LabelSort, $b->LabelSort); });
+	}
+
+	apcu_store('feeds-index-' . $type . '-' . $name, $feeds, 43200); // 12 hours
+}
+?><?= Template::Header(['title' => $ucType . ' Ebook Feeds by ' . $ucTitle, 'description' => 'A list of available ' . $ucType . ' feeds of Standard Ebooks ebooks by ' . $lcTitle . '.']) ?>
+<main>
+	<article>
+		<h1><?= $ucType ?> Ebook Feeds by <?= $ucTitle ?></h1>
+		<?= Template::FeedHowTo() ?>
+		<section id="ebooks-by-<?= $lcTitle ?>">
+			<h2>Ebooks by <?= $lcTitle ?></h2>
+			<ul class="feed">
+				<? foreach($feeds as $feed){ ?>
+				<li>
+					<p><a href="<? if($GLOBALS['User'] !== null){ ?>https://<?= rawurlencode($GLOBALS['User']->Email) ?>@<?= SITE_DOMAIN ?><? } ?><?= Formatter::ToPlainText($feed->Url) ?>"><?= Formatter::ToPlainText($feed->Label) ?></a></p>
+					<p class="url"><? if($GLOBALS['User'] !== null){ ?>https://<?= rawurlencode($GLOBALS['User']->Email) ?>@<?= SITE_DOMAIN ?><? }else{ ?><?= SITE_URL ?><? } ?><?= Formatter::ToPlainText($feed->Url) ?></p>
+				</li>
+				<? } ?>
+			</ul>
+		</section>
+	</article>
+</main>
+<?= Template::Footer() ?>

www/feeds/index.php

@@ -18,8 +18,8 @@ require_once('Core.php');
 			<p>They’re also perfect for scripting, or for libraries or other organizations who wish to download, process, and keep up to date with our catalog of ebooks.</p>
 			<ul class="feed">
 				<li>
-					<p><a href="/feeds/opds">The Standard Ebooks OPDS feed</a></p>
+					<p><a href="<? if($GLOBALS['User'] !== null){ ?>https://<?= rawurlencode($GLOBALS['User']->Email) ?>@<?= SITE_DOMAIN ?><? } ?>/feeds/opds">The Standard Ebooks OPDS feed</a></p>
-					<p class="url"><?= SITE_URL ?>/feeds/opds</p>
+					<p class="url"><? if($GLOBALS['User'] !== null){ ?>https://<?= rawurlencode($GLOBALS['User']->Email) ?>@<?= SITE_DOMAIN ?><? }else{ ?><?= SITE_URL ?><? } ?>/feeds/opds</p>
 				</li>
 			</ul>
 		</section>

www/feeds/opds/search.php

@@ -15,7 +15,7 @@ catch(\Exception $ex){
 	http_response_code(500);
 	exit();
 }
-print("<?xml version=\"1.0\" encoding=\"utf-8\"?>\n<?xml-stylesheet href=\"/feeds/opds/style\" type=\"text/xsl\"?>\n");
+print("<?xml version=\"1.0\" encoding=\"utf-8\"?>\n<?xml-stylesheet href=\"". SITE_URL . "/feeds/opds/style\" type=\"text/xsl\"?>\n");
 ?>
 <feed xmlns="http://www.w3.org/2005/Atom" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:schema="http://schema.org/" xmlns:opensearch="http://a9.com/-/spec/opensearch/1.1/">
 	<id><?= SITE_URL ?>/feeds/opds/all?query=<?= urlencode($query) ?></id>

www/feeds/rss/index.php

@@ -8,7 +8,7 @@ require_once('Core.php');
 		<p>RSS feeds are the predecessors of <a href="/feeds/atom">Atom feeds</a>. They contain less information than Atom feeds, but might be better supported by some news readers.</p>
 		<?= Template::FeedHowTo() ?>
 		<section id="general-feeds">
-			<h2>General Feeds</h2>
+			<h2>General feeds</h2>
 			<ul class="feed">
 				<li>
 					<p><a href="/feeds/rss/new-releases">New releases</a> (Public)</p>
@@ -22,15 +22,18 @@ require_once('Core.php');
 				</li>
 			</ul>
 		</section>
-		<section id="ebooks-by-subject">
+		<section id="ebooks-by-collection">
-			<h2>Ebooks by subject</h2>
+			<h2>Feeds by topic</h2>
 			<ul class="feed">
-				<? foreach(SE_SUBJECTS as $subject){ ?>
 				<li>
-					<p><a href="/feeds/rss/subjects/<?= Formatter::MakeUrlSafe($subject) ?>"><?= Formatter::ToPlainText($subject) ?></a></p>
+					<p><a href="/feeds/rss/authors">Feeds by author</a></p>
-					<p class="url"><?= SITE_URL ?>/feeds/rss/subjects/<?= Formatter::MakeUrlSafe($subject) ?></p>
+				</li>
+				<li>
+					<p><a href="/feeds/rss/collections">Feeds by collection</a></p>
+				</li>
+				<li>
+					<p><a href="/feeds/rss/subjects">Feeds by subject</a></p>
 				</li>
-				<? } ?>
 			</ul>
 		</section>
 	</section>

www/feeds/rss/search.php

@@ -16,7 +16,7 @@ catch(\Exception $ex){
 	include(WEB_ROOT . '/404.php');
 	exit();
 }
-print("<?xml version=\"1.0\" encoding=\"utf-8\"?>\n<?xml-stylesheet href=\"/feeds/rss/style\" type=\"text/xsl\"?>\n");
+print("<?xml version=\"1.0\" encoding=\"utf-8\"?>\n<?xml-stylesheet href=\"" . SITE_URL . "/feeds/rss/style\" type=\"text/xsl\"?>\n");
 ?>
 <rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom" xmlns:media="http://search.yahoo.com/mrss/" xmlns:opensearch="http://a9.com/-/spec/opensearch/1.1/">
 	<channel>

www/feeds/rss/subjects/index.php

@@ -1,22 +0,0 @@
-<?
-require_once('Core.php');
-
-?><?= Template::Header(['title' => 'RSS 2.0 Ebook Feeds by Subject', 'description' => 'A list of available RSS 2.0 feeds of Standard Ebooks ebooks by subject.']) ?>
-<main>
-	<article>
-		<h1>RSS 2.0 Ebook Feeds by Subject</h1>
-		<?= Template::FeedHowTo() ?>
-		<section id="ebooks-by-subject">
-			<h2>Ebooks by subject</h2>
-			<ul class="feed">
-				<? foreach(SE_SUBJECTS as $subject){ ?>
-				<li>
-					<p><a href="/feeds/rss/subjects/<?= Formatter::MakeUrlSafe($subject) ?>"><?= Formatter::ToPlainText($subject) ?></a></p>
-					<p class="url"><?= SITE_URL ?>/feeds/rss/subjects/<?= Formatter::MakeUrlSafe($subject) ?></p>
-				</li>
-				<? } ?>
-			</ul>
-		</section>
-	</article>
-</main>
-<?= Template::Footer() ?>