From 30ac765c7cd66621f581040fa52d97a451f6f51f Mon Sep 17 00:00:00 2001
From: Marcel Werk <burntime@woltlab.com>
Date: Wed, 8 Jun 2016 15:18:20 +0200
Subject: [PATCH] Added links to other (language) versions of an article

---
 com.woltlab.wcf/templates/article.tpl         | 18 +++++++++++++
 .../files/lib/data/article/Article.class.php  | 27 +++++++++++++++++++
 .../article/content/ArticleContent.class.php  | 15 +++++++++++
 3 files changed, 60 insertions(+)

diff --git a/com.woltlab.wcf/templates/article.tpl b/com.woltlab.wcf/templates/article.tpl
index df85e5a4f6..87a693b356 100644
--- a/com.woltlab.wcf/templates/article.tpl
+++ b/com.woltlab.wcf/templates/article.tpl
@@ -48,6 +48,16 @@
 	</header>
 {/capture}
 
+{capture assign='headContent'}
+	{if $article->isMultilingual}
+		{foreach from=$article->getLanguageLinks() item='langArticleContent'}
+			{if $langArticleContent->getLanguage()}
+				<link rel="alternate" hreflang="{$langArticleContent->getLanguage()->languageCode}" href="{$langArticleContent->getLink()}" />
+			{/if}
+		{/foreach}
+	{/if}
+{/capture}
+
 {include file='header'}
 
 {if $articleContent->getImage()}
@@ -85,6 +95,14 @@
 	
 	<ul class="articleLikeButtons buttonGroup"></ul>
 	
+	{if $article->isMultilingual}
+		{foreach from=$article->getLanguageLinks() item='langArticleContent'}
+			{if $langArticleContent->getLanguage() && $langArticleContent->languageID != $articleContent->languageID}
+				<a href="{$langArticleContent->getLink()}">{$langArticleContent->getLanguage()->languageName}</a>
+			{/if}
+		{/foreach}
+	{/if}
+	
 	{if ENABLE_SHARE_BUTTONS}
 		<section class="section jsOnly">
 			<h2 class="sectionTitle">{lang}wcf.message.share{/lang}</h2>
diff --git a/wcfsetup/install/files/lib/data/article/Article.class.php b/wcfsetup/install/files/lib/data/article/Article.class.php
index f2a3f392c0..d3988d1282 100644
--- a/wcfsetup/install/files/lib/data/article/Article.class.php
+++ b/wcfsetup/install/files/lib/data/article/Article.class.php
@@ -48,6 +48,12 @@ class Article extends DatabaseObject implements ILinkableObject {
 	 */
 	public $articleContent;
 	
+	/**
+	 * language links
+	 * @var	ArticleContent[]
+	 */
+	public $languageLinks;
+	
 	/**
 	 * article's category
 	 * @var ArticleCategory
@@ -205,6 +211,27 @@ class Article extends DatabaseObject implements ILinkableObject {
 		return $this->articleContent;
 	}
 	
+	/**
+	 * Returns the article's language links.
+	 *
+	 * @return	ArticleContent[]
+	 */
+	public function getLanguageLinks() {
+		if ($this->languageLinks === null) {
+			$this->languageLinks = [];
+			$sql = "SELECT	articleContentID, title, languageID
+				FROM	wcf" . WCF_N . "_article_content
+				WHERE	articleID = ?";
+			$statement = WCF::getDB()->prepareStatement($sql);
+			$statement->execute([$this->articleID]);
+			while ($row = $statement->fetchArray()) {
+				$this->languageLinks[($row['languageID'] ?: 0)] = new ArticleContent(null, $row);
+			}
+		}
+		
+		return $this->languageLinks;
+	}
+	
 	/**
 	 * Returns the category of the article.
 	 *
diff --git a/wcfsetup/install/files/lib/data/article/content/ArticleContent.class.php b/wcfsetup/install/files/lib/data/article/content/ArticleContent.class.php
index 126d88ddc1..ac4d51457f 100644
--- a/wcfsetup/install/files/lib/data/article/content/ArticleContent.class.php
+++ b/wcfsetup/install/files/lib/data/article/content/ArticleContent.class.php
@@ -3,7 +3,9 @@ namespace wcf\data\article\content;
 use wcf\data\article\Article;
 use wcf\data\DatabaseObject;
 use wcf\data\ILinkableObject;
+use wcf\data\language\Language;
 use wcf\system\html\output\HtmlOutputProcessor;
+use wcf\system\language\LanguageFactory;
 use wcf\system\message\embedded\object\MessageEmbeddedObjectManager;
 use wcf\system\request\IRouteController;
 use wcf\system\request\LinkHandler;
@@ -88,6 +90,19 @@ class ArticleContent extends DatabaseObject implements ILinkableObject, IRouteCo
 		return $this->article;
 	}
 	
+	/**
+	 * Returns the language of this article content as language object.
+	 * 
+	 * @return Language|null
+	 */
+	public function getLanguage() {
+		if ($this->languageID) {
+			return LanguageFactory::getInstance()->getLanguage($this->languageID);
+		}
+		
+		return null;
+	}
+	
 	public static function getArticleContent($articleID, $languageID) {
 		if ($languageID !== null) {
 			$sql = "SELECT  *
-- 
2.20.1