Add related article URLs for Atom and JSON

lib/Entry.php

@@ -13,7 +13,7 @@ abstract class Entry {
     protected $feed;
 
     public $link;
-    public $externalLink;
+    public $relatedLink;
     public $title;
     public $summary;
     public $categories;
@@ -26,6 +26,7 @@ abstract class Entry {
     protected function parse() {
         $this->id = $this->getId();
         $this->link = $this->getLink();
+        $this->relatedLink = $this->getRelatedLink();
         $this->title = $this->getTitle();
         $this->people = $this->getPeople();
         $this->author = $this->people->primary() ?? $this->feed->author;
@@ -57,4 +58,7 @@ abstract class Entry {
 
     /** General function to fetch the Web URL of the entry */
     abstract public function getLink(): string;
+
+    /** General function to fetch the URL of a article related to the entry */
+    abstract public function getRelatedLink(): string;
 }

lib/JSON/Entry.php

@@ -72,4 +72,9 @@ class Entry extends \JKingWeb\Lax\Entry {
     public function getLink(): string {
         return $this->fetchUrl("url") ?? "";
     }
+
+    /** General function to fetch the URL of a article related to the entry */
+    public function getRelatedLink(): string {
+        return $this->fetchUrl("external_url") ?? "";
+    }
 }

lib/XML/Entry.php

@@ -63,4 +63,12 @@ class Entry extends \JKingWeb\Lax\Entry {
     public function getLink(): string {
         return $this->getLinkAtom() ?? $this->getLinkRss1() ?? $this->getLinkRss2() ?? "";
     }
+
+    /** General function to fetch the URL of a article related to the entry
+     * 
+     * This is only reliable with Atom feeds
+     */
+    public function getRelatedLink(): string {
+        return $this->getRelatedLinkAtom() ?? "";
+    }
 }

lib/XML/Primitives/Construct.php

@@ -233,7 +233,7 @@ trait Construct {
     /** Primitive to fetch the list of entries in an RDF feed */
     protected function getEntriesRss1() {
         $out = [];
-        foreach ($this->fetchElements("rss1:item|rss0:item", $this->subject->ownerDocument->documentElement) ?? $this->fetchElements("rss1:item|rss0:item") ?? [] as $node) {
+        foreach ($this->fetchElements("rss1:item", $this->subject->ownerDocument->documentElement) ?? $this->fetchElements("rss1:item") ?? $this->fetchElements("rss0:item", $this->subject->ownerDocument->documentElement) ?? $this->fetchElements("rss0:item") ?? [] as $node) {
             $out[] = new FeedEntry($node, $this, $this->xpath);
         }
         return count($out) ? $out : null;
@@ -247,4 +247,11 @@ trait Construct {
         }
         return count($out) ? $out : null;
     }
+
+    /** Primitive to fetch the URL of a article related to the entry */
+    protected function getRelatedLinkAtom() {
+        // FIXME: Atom link fetching should ideally prefer links to text/html resources or the like over e.g. other-format newsfeeds, generic XML, images, etc
+        $node = $this->fetchAtomRelations("related");
+        return $node->length ? $this->resolveNodeUrl($node->item(0), "href") : null;
+    }
 }