i18n database object list class

this makes it possible to provide a list of objects in a real alphabetical order
for performance-reasons it should be used when needed only (e.g. when sortField is title and title might contain language items)

diff --git a/wcfsetup/install/files/lib/data/I18nDatabaseObjectList.class.php b/wcfsetup/install/files/lib/data/I18nDatabaseObjectList.class.php
new file mode 100644 (file)
index 0000000..a75f928
--- /dev/null
+++ b/wcfsetup/install/files/lib/data/I18nDatabaseObjectList.class.php
@@ -0,0 +1,60 @@
+<?php
+namespace wcf\data;
+use wcf\system\WCF;
+use wcf\util\StringUtil;
+
+/**
+ * Abstract class for a list of database objects with better sorting of i18n-based columns.
+ *
+ * @author     Florian Gail
+ * @copyright  2001-2017 WoltLab GmbH
+ * @license    GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
+ * @package    WoltLabSuite\Core\Data
+ * @since      3.1
+ */
+abstract class I18nDatabaseObjectList extends DatabaseObjectList {
+       /**
+        * Array of column names, that are eventually filled with language items.
+        * Those additional joins are going to slow down the system; you should use this
+        * class only when it's really needed.
+        * The key represents the original field name.
+        * The value represents the new field name containing the localized field-value.
+        *
+        * @example   [ 'title' => 'titleSortField' ]
+        *
+        * @var string[]
+        */
+       public $i18nFields = [];
+       
+       /**
+        * @inheritDoc
+        * @param integer $languageID id of the language that should be used
+        * @throws \DomainException
+        */
+       public function __construct($languageID = null) {
+               parent::__construct();
+               
+               if ($languageID === null) {
+                       $languageID = WCF::getUser()->languageID;
+               }
+               
+               if (!empty($this->i18nFields)) {
+                       if (count($this->i18nFields) !== count(array_flip($this->i18nFields))) {
+                               throw new \DomainException("Array values of '".$this->className."::\$i18nFields' must be unique.");
+                       }
+                       
+                       foreach ($this->i18nFields as $key => $value) {
+                               if (!preg_match('/^[a-z][a-zA-Z0-9]*$/', $key) || !preg_match('/^[a-z][a-zA-Z0-9]*$/', $value)) {
+                                       throw new \DomainException("Array keys and values of '".$this->className."::\$i18nFields' must start with a small letter and consist of letters and number only.");
+                               }
+                               
+                               $matchTable =  'i18n_' . StringUtil::getHash($key);
+                               
+                               $this->sqlSelects .= (!empty($this->sqlSelects) ? ', ' : '') . "COALESCE(" . $matchTable . ".languageItemValue, " . $this->getDatabaseTableAlias() . "." . $key . ") AS " . $value;
+                               $this->sqlJoins .= " LEFT JOIN wcf" . WCF_N . "_language_item " . $matchTable . "
+                                               ON " . $matchTable . ".languageItem = " . $this->getDatabaseTableAlias() . "." . $key . "
+                                               AND " . $matchTable . ".languageID = " . $languageID;
+                       }
+               }
+       }
+}