From 78db8ddfc0c68f2cc976e6fc79d9c4718d0e8e35 Mon Sep 17 00:00:00 2001
From: Marcel Werk <burntime@woltlab.com>
Date: Sat, 29 Jun 2013 19:07:50 +0200
Subject: [PATCH] Added data import function (WIP)

---
 com.woltlab.wcf/acpMenu.xml                   |   6 +
 com.woltlab.wcf/objectType.xml                |  38 +++
 com.woltlab.wcf/objectTypeDefinition.xml      |  10 +
 com.woltlab.wcf/userGroupOption.xml           |   6 +
 .../files/acp/templates/dataImport.tpl        | 202 ++++++++++++++++
 .../lib/acp/form/DataImportForm.class.php     | 227 ++++++++++++++++++
 .../data/user/group/UserGroupAction.class.php |   6 +-
 .../exporter/AbstractExporter.class.php       | 143 +++++++++++
 .../lib/system/exporter/IExporter.class.php   |  90 +++++++
 .../lib/system/importer/IImporter.class.php   |  23 ++
 .../system/importer/ImportHandler.class.php   | 106 ++++++++
 .../importer/UserGroupImporter.class.php      |  30 +++
 .../system/importer/UserImporter.class.php    |  40 +++
 .../lib/system/worker/ImportWorker.class.php  |  93 +++++++
 wcfsetup/setup/db/install.sql                 |  10 +
 15 files changed, 1028 insertions(+), 2 deletions(-)
 create mode 100644 wcfsetup/install/files/acp/templates/dataImport.tpl
 create mode 100644 wcfsetup/install/files/lib/acp/form/DataImportForm.class.php
 create mode 100644 wcfsetup/install/files/lib/system/exporter/AbstractExporter.class.php
 create mode 100644 wcfsetup/install/files/lib/system/exporter/IExporter.class.php
 create mode 100644 wcfsetup/install/files/lib/system/importer/IImporter.class.php
 create mode 100644 wcfsetup/install/files/lib/system/importer/ImportHandler.class.php
 create mode 100644 wcfsetup/install/files/lib/system/importer/UserGroupImporter.class.php
 create mode 100644 wcfsetup/install/files/lib/system/importer/UserImporter.class.php
 create mode 100644 wcfsetup/install/files/lib/system/worker/ImportWorker.class.php

diff --git a/com.woltlab.wcf/acpMenu.xml b/com.woltlab.wcf/acpMenu.xml
index 99f3c3fca3..cdb9d329c1 100644
--- a/com.woltlab.wcf/acpMenu.xml
+++ b/com.woltlab.wcf/acpMenu.xml
@@ -92,6 +92,12 @@
 			<parent>wcf.acp.menu.link.maintenance</parent>
 			<permissions>admin.system.canManageApplication</permissions>
 		</acpmenuitem>
+		
+		<acpmenuitem name="wcf.acp.menu.link.maintenance.import">
+			<controller><![CDATA[wcf\acp\form\DataImport]]></controller>
+			<parent>wcf.acp.menu.link.maintenance</parent>
+			<permissions>admin.system.canImportData</permissions>
+		</acpmenuitem>
 		<!-- /maintenance -->
 		
 		<!-- log -->
diff --git a/com.woltlab.wcf/objectType.xml b/com.woltlab.wcf/objectType.xml
index c15955563d..4d1172930a 100644
--- a/com.woltlab.wcf/objectType.xml
+++ b/com.woltlab.wcf/objectType.xml
@@ -210,5 +210,43 @@
 			<name>com.woltlab.wcf.label</name>
 			<definitionname>com.woltlab.wcf.acl</definitionname>
 		</type>
+		
+		<!-- importers -->
+		<type>
+			<name>com.woltlab.wcf.user</name>
+			<definitionname>com.woltlab.wcf.importer</definitionname>
+			<classname><![CDATA[wcf\system\importer\UserImporter]]></classname>
+		</type>
+		<type>
+			<name>com.woltlab.wcf.user.group</name>
+			<definitionname>com.woltlab.wcf.importer</definitionname>
+			<classname><![CDATA[wcf\system\importer\UserGroupImporter]]></classname>
+		</type>
+		<!-- <type>
+			<name>com.woltlab.wcf.user.option</name>
+			<definitionname>com.woltlab.wcf.importer</definitionname>
+			<classname><![CDATA[wcf\system\importer\UserOptionImporter]]></classname>
+		</type>
+		<type>
+			<name>com.woltlab.wcf.user.avatar</name>
+			<definitionname>com.woltlab.wcf.importer</definitionname>
+			<classname><![CDATA[wcf\system\importer\UserAvatarImporter]]></classname>
+		</type>
+		<type>
+			<name>com.woltlab.wcf.user.comment</name>
+			<definitionname>com.woltlab.wcf.importer</definitionname>
+			<classname><![CDATA[wcf\system\importer\UserCommentImporter]]></classname>
+		</type>
+		<type>
+			<name>com.woltlab.wcf.user.comment.response</name>
+			<definitionname>com.woltlab.wcf.importer</definitionname>
+			<classname><![CDATA[wcf\system\importer\UserCommentResponseImporter]]></classname>
+		</type>
+		<type>
+			<name>com.woltlab.wcf.user.follower</name>
+			<definitionname>com.woltlab.wcf.importer</definitionname>
+			<classname><![CDATA[wcf\system\importer\UserFollowerImporter]]></classname>
+		</type>-->
+		<!-- /importers -->
 	</import>
 </data>
\ No newline at end of file
diff --git a/com.woltlab.wcf/objectTypeDefinition.xml b/com.woltlab.wcf/objectTypeDefinition.xml
index b53929cef2..2fba986584 100644
--- a/com.woltlab.wcf/objectTypeDefinition.xml
+++ b/com.woltlab.wcf/objectTypeDefinition.xml
@@ -129,5 +129,15 @@
 			<name>com.woltlab.wcf.poll</name>
 			<interfacename><![CDATA[wcf\system\poll\IPollHandler]]></interfacename>
 		</definition>
+		
+		<definition>
+			<name>com.woltlab.wcf.importer</name>
+			<interfacename><![CDATA[wcf\system\importer\IImporter]]></interfacename>
+		</definition>
+		
+		<definition>
+			<name>com.woltlab.wcf.exporter</name>
+			<interfacename><![CDATA[wcf\system\exporter\IExporter]]></interfacename>
+		</definition>
 	</import>
 </data>
diff --git a/com.woltlab.wcf/userGroupOption.xml b/com.woltlab.wcf/userGroupOption.xml
index 46add8db97..fe420e20b2 100644
--- a/com.woltlab.wcf/userGroupOption.xml
+++ b/com.woltlab.wcf/userGroupOption.xml
@@ -137,6 +137,12 @@
 				<defaultvalue>0</defaultvalue>
 				<admindefaultvalue>1</admindefaultvalue>
 			</option>
+			<option name="admin.system.canImportData">
+				<categoryname>admin.system</categoryname>
+				<optiontype>boolean</optiontype>
+				<defaultvalue>0</defaultvalue>
+				<admindefaultvalue>1</admindefaultvalue>
+			</option>
 			<option name="admin.system.canManageCronjob">
 				<categoryname>admin.system</categoryname>
 				<optiontype>boolean</optiontype>
diff --git a/wcfsetup/install/files/acp/templates/dataImport.tpl b/wcfsetup/install/files/acp/templates/dataImport.tpl
new file mode 100644
index 0000000000..e8fb95482b
--- /dev/null
+++ b/wcfsetup/install/files/acp/templates/dataImport.tpl
@@ -0,0 +1,202 @@
+{include file='header' pageTitle='wcf.acp.dataImport'}
+
+<script type="text/javascript">
+	//<![CDATA[
+	$(function() {
+		{if $queue|isset}
+			WCF.Language.addObject({
+				{implode from=$importers item=importer}'wcf.acp.dataImport.import.{@$importer}': '{lang}wcf.acp.dataImport.import.{@$importer}{/lang}'{/implode}
+			});
+			
+			var $queue = [ {implode from=$queue item=item}'{@$item}'{/implode} ];
+			var $queueID = 0;
+			
+			function runProcess() {
+				new WCF.ACP.Worker('mail', 'wcf\\system\\worker\\ImportWorker', WCF.Language.get('wcf.acp.dataImport.import.' + $queue[$queueID]), {
+					objectType: $queue[$queueID]
+				}, function(worker) {
+					$queueID++;
+					if ($queueID < $queue.length) {
+						worker._dialog.wcfDialog('close');
+						runProcess();
+					}
+				});
+			}
+			
+			runProcess();
+		{/if}
+		
+		$('.jsImportSection').change(function(event) {
+			var $section = $(event.currentTarget);
+			window.dtdesign = $section;
+			if ($section.is(':checked')) {
+				$section.parent().next().find('input[type=checkbox]').prop('checked', 'checked');
+			}
+			else {
+				$section.parent().next().find('input[type=checkbox]').prop('checked', false);
+			}
+		});
+
+		$('.jsImportItem').change(function(event) {
+			var $item = $(event.currentTarget);
+			if ($item.is(':checked')) {
+				$item.parents('.jsImportCollection').find('.jsImportSection').prop('checked', 'checked');
+			}
+			else {
+				var $collection = $item.parents('.jsImportCollection');
+				var $checkedItems = $collection.find('.jsImportItem:checked');
+				if (!$checkedItems.length) {
+					$collection.find('.jsImportSection').prop('checked', false);
+				}
+			}
+		});
+	});
+	//]]>
+</script>
+
+<header class="boxHeadline">
+	<h1>{lang}wcf.acp.dataImport{/lang}</h1>
+</header>
+
+{if $errorField}
+	<p class="error">{lang}wcf.global.form.error{/lang} ({$errorField})</p>
+{/if}
+
+<div class="contentNavigation">
+	{hascontent}
+		<nav>
+			<ul>
+				{content}
+					{event name='contentNavigationButtons'}
+				{/content}
+			</ul>
+		</nav>
+	{/hascontent}
+</div>
+
+{if !$exporterName}
+	{if !$availableExporters|count}
+		<p class="info">{lang}wcf.acp.dataImport.selectExporter.noExporters{/lang}</p>
+	{else}
+		<form method="get" action="{link controller='DataImport'}{/link}">
+			<div class="container containerPadding marginTop">
+				<fieldset>
+					<legend>{lang}wcf.acp.dataImport.selectExporter{/lang}</legend>
+					
+					<dl{if $errorField == 'exporterName'} class="formError"{/if}>
+						<dt><label for="exporterName">{lang}wcf.acp.dataImport.exporter{/lang}</label></dt>
+						<dd>
+							<select name="exporterName" id="exporterName">
+								{foreach from=$availableExporters key=availableExporterName item=availableExporter}
+									<option value="{@$availableExporterName}">{lang}wcf.acp.dataImport.exporter.{@$availableExporterName}{/lang}</option>
+								{/foreach}
+							</select>
+							{if $errorField == 'exporterName'}
+								<small class="innerError">
+									{if $errorType == 'empty'}
+										{lang}wcf.global.form.error.empty{/lang}
+									{else}
+										{lang}wcf.acp.dataImport.exporterName.error.{@$errorType}{/lang}
+									{/if}
+								</small>
+							{/if}
+						</dd>
+					</dl>
+					
+					{event name='selectExporterFields'}
+				</fieldset>
+			</div>
+		
+			<div class="formSubmit">
+				{@SID_INPUT_TAG}
+				<input type="submit" value="{lang}wcf.global.button.submit{/lang}" accesskey="s" />
+			</div>
+		</form>
+	{/if}
+{else}
+	<form method="post" action="{link controller='DataImport'}{/link}">
+		<div class="container containerPadding marginTop">
+			<fieldset>
+				<legend>{lang}wcf.acp.dataImport.configure.data{/lang}</legend>
+				
+				<small>{lang}wcf.acp.dataImport.configure.data.description{/lang}</small>
+				
+				{foreach from=$supportedData key=objectTypeName item=objectTypes}
+					<dl class="wide">
+						<dd class="jsImportCollection">
+							<label><input type="checkbox" name="selectedData[]" value="{@$objectTypeName}" class="jsImportSection"{if $objectTypeName|in_array:$selectedData}checked="checked" {/if}/> {lang}wcf.acp.dataImport.data.{@$objectTypeName}{/lang}</label>
+							<p>
+								{foreach from=$objectTypes item=objectTypeName}
+									<label><input type="checkbox" name="selectedData[]" value="{@$objectTypeName}" class="jsImportItem"{if $objectTypeName|in_array:$selectedData}checked="checked" {/if}/> {lang}wcf.acp.dataImport.data.{@$objectTypeName}{/lang}</label>
+								{/foreach}
+							</p>
+						</dd>
+					</dl>
+				{/foreach}
+			</fieldset>
+			
+			<fieldset>
+				<legend>{lang}wcf.acp.dataImport.configure.settings{/lang}</legend>
+				
+				
+			</fieldset>
+			
+			<fieldset>
+				<legend>{lang}wcf.acp.dataImport.configure.database{/lang}</legend>
+				
+				<dl>
+					<dt><label for="dbHost">{lang}wcf.acp.dataImport.configure.database.host{/lang}</label></dt>
+					<dd>
+						<input type="text" id="dbHost" name="dbHost" value="{$dbHost}" class="long" />
+					</dd>
+				</dl>
+				
+				<dl>
+					<dt><label for="dbUser">{lang}wcf.acp.dataImport.configure.database.user{/lang}</label></dt>
+					<dd>
+						<input type="text" id="dbUser" name="dbUser" value="{$dbUser}" class="medium" />
+					</dd>
+				</dl>
+				
+				<dl>
+					<dt><label for="dbPassword">{lang}wcf.acp.dataImport.configure.database.password{/lang}</label></dt>
+					<dd>
+						<input type="password" id="dbPassword" name="dbPassword" value="{$dbPassword}" class="medium" />
+					</dd>
+				</dl>
+				
+				<dl>
+					<dt><label for="dbName">{lang}wcf.acp.dataImport.configure.database.name{/lang}</label></dt>
+					<dd>
+						<input type="text" id="dbName" name="dbName" value="{$dbName}" class="medium" />
+					</dd>
+				</dl>
+				
+				<dl>
+					<dt><label for="dbPrefix">{lang}wcf.acp.dataImport.configure.database.prefix{/lang}</label></dt>
+					<dd>
+						<input type="text" id="dbPrefix" name="dbPrefix" value="{$dbPrefix}" class="short" />
+					</dd>
+				</dl>
+			</fieldset>
+			
+			<fieldset>
+				<legend>{lang}wcf.acp.dataImport.configure.fileSystem{/lang}</legend>
+				
+				<dl>
+					<dt><label for="fileSystemPath">{lang}wcf.acp.dataImport.configure.fileSystem.path{/lang}</label></dt>
+					<dd>
+						<input type="text" id="fileSystemPath" name="fileSystemPath" value="{$fileSystemPath}" class="long" />
+					</dd>
+				</dl>
+			</fieldset>
+		</div>
+	
+		<div class="formSubmit">
+			<input type="hidden" name="exporterName" value="{$exporterName}" />
+			<input type="submit" value="{lang}wcf.global.button.submit{/lang}" accesskey="s" />
+		</div>
+	</form>
+{/if}
+
+{include file='footer'}
diff --git a/wcfsetup/install/files/lib/acp/form/DataImportForm.class.php b/wcfsetup/install/files/lib/acp/form/DataImportForm.class.php
new file mode 100644
index 0000000000..55707c6b21
--- /dev/null
+++ b/wcfsetup/install/files/lib/acp/form/DataImportForm.class.php
@@ -0,0 +1,227 @@
+<?php
+namespace wcf\acp\form;
+use wcf\data\object\type\ObjectTypeCache;
+use wcf\form\AbstractForm;
+use wcf\system\exception\IllegalLinkException;
+use wcf\system\exception\UserInputException;
+use wcf\system\WCF;
+use wcf\util\StringUtil;
+
+/**
+ * Provides the data import form.
+ *
+ * @author	Marcel Werk
+ * @copyright	2001-2013 WoltLab GmbH
+ * @license	GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
+ * @package	com.woltlab.wcf.user
+ * @subpackage	acp.form
+ * @category	Community Framework
+ */
+class DataImportForm extends AbstractForm {
+	/**
+	 * @see	wcf\page\AbstractPage::$activeMenuItem
+	 */
+	public $activeMenuItem = 'wcf.acp.menu.link.maintenance.import';
+	
+	/**
+	 * @see	wcf\page\AbstractPage::$neededPermissions
+	 */
+	public $neededPermissions = array('admin.system.canImportData');
+	
+	/**
+	 * list of available exporters
+	 * @var array
+	 */
+	public $exporters = array();
+	
+	/**
+	 * exporter name
+	 * @var string
+	 */
+	public $exporterName = '';
+	
+	/**
+	 * exporter object
+	 * @var wcf\system\exporter\IExporter
+	 */
+	public $exporter = null;
+	
+	/**
+	 * list of available importers
+	 * @var array<string>
+	 */
+	public $importers = array();
+	
+	/**
+	 * list of supported data types
+	 * @var array
+	 */
+	public $supportedData = array();
+	
+	/**
+	 * selected data types
+	 * @var array
+	 */
+	public $selectedData = array();
+	
+	/**
+	 * database host name
+	 * @var string
+	 */
+	public $dbHost = '';
+	
+	/**
+	 * database user name
+	 * @var string
+	 */
+	public $dbUser = '';
+	
+	/**
+	 * database password
+	 * @var string
+	 */
+	public $dbPassword = '';
+	
+	/**
+	 * database name
+	 * @var string
+	 */
+	public $dbName = '';
+	
+	/**
+	 * database table prefix
+	 * @var string
+	 */
+	public $dbPrefix = '';
+	
+	/**
+	 * file system path
+	 * @var string
+	 */
+	public $fileSystemPath = '';
+	
+	/**
+	 * @see wcf\page\IPage::readParameters()
+	 */
+	public function readParameters() {
+		parent::readParameters();
+		
+		// get available exporters/importers
+		$this->exporters = ObjectTypeCache::getInstance()->getObjectTypes('com.woltlab.wcf.exporter');
+		$this->importers = array_keys(ObjectTypeCache::getInstance()->getObjectTypes('com.woltlab.wcf.importer'));
+		
+		if (isset($_REQUEST['exporterName'])) {
+			$this->exporterName = $_REQUEST['exporterName'];
+			if (!isset($this->exporters[$this->exporterName])) {
+				throw new IllegalLinkException();
+			}
+			
+			$this->exporter = $this->exporters[$this->exporterName]->getProcessor();
+			$this->supportedData = $this->exporter->getSupportedData();
+			
+			// remove unsupported data
+			foreach ($this->supportedData as $key => $subData) {
+				if (!in_array($key, $this->importers)) {
+					unset($this->supportedData[$key]);
+					continue;
+				}
+				
+				foreach ($subData as $key2 => $value) {
+					if (!in_array($value, $this->importers)) {
+						unset($this->supportedData[$key][$key2]);
+					}
+				}
+			}
+			
+			// get default database prefix
+			if (!count($_POST)) {
+				$this->dbPrefix = $this->exporter->getDefaultDatabasePrefix();
+			}
+		}
+	}
+	
+	/**
+	 * @see wcf\form\IForm::readFormParameters()
+	 */
+	public function readFormParameters() {
+		parent::readFormParameters();
+	
+		if (isset($_POST['selectedData']) && is_array($_POST['selectedData'])) $this->selectedData = $_POST['selectedData'];
+		
+		if (isset($_POST['dbHost'])) $this->dbHost = StringUtil::trim($_POST['dbHost']);
+		if (isset($_POST['dbUser'])) $this->dbUser = StringUtil::trim($_POST['dbUser']);
+		if (isset($_POST['dbPassword'])) $this->dbPassword = $_POST['dbPassword'];
+		if (isset($_POST['dbName'])) $this->dbName = StringUtil::trim($_POST['dbName']);
+		if (isset($_POST['dbPrefix'])) $this->dbPrefix = StringUtil::trim($_POST['dbPrefix']);
+		if (isset($_POST['fileSystemPath'])) $this->fileSystemPath = StringUtil::trim($_POST['fileSystemPath']);
+	}
+	
+	/**
+	 * @see wcf\form\IForm::validate()
+	 */
+	public function validate() {
+		parent::validate();
+	
+		$this->exporter->setData($this->dbHost, $this->dbUser, $this->dbPassword, $this->dbName, $this->dbPrefix, $this->fileSystemPath);
+		
+		// validate database Access
+		if (!$this->exporter->validateDatabaseAccess()) {
+			throw new UserInputException('database');
+		}
+		
+		// validate selected data
+		if (!$this->exporter->validateSelectedData($this->selectedData)) {
+			throw new UserInputException('selectedData');
+		}
+		
+		// validate file access
+		if (!$this->exporter->validateFileAccess()) {
+			throw new UserInputException('fileSystemPath');
+		}
+	}
+	
+	/**
+	 * @see wcf\form\IForm::save()
+	 */
+	public function save() {
+		parent::save();
+	
+		// get queue
+		$queue = $this->exporter->getQueue();
+		
+		// save import data
+		WCF::getSession()->register('importData', array(
+			'exporterName' => $this->exporterName,
+			'dbHost' => $this->dbHost,
+			'dbUser' => $this->dbUser,
+			'dbPassword' => $this->dbPassword,
+			'dbName' => $this->dbName,
+			'dbPrefix' => $this->dbPrefix,
+			'fileSystemPath' => $this->fileSystemPath,
+		));
+		
+		WCF::getTPL()->assign('queue', $queue);
+	}
+	
+	/**
+	 * @see wcf\page\IPage::assignVariables()
+	 */
+	public function assignVariables() {
+		parent::assignVariables();
+	
+		WCF::getTPL()->assign(array(
+			'exporter' => $this->exporter,
+			'importers' => $this->importers,
+			'exporterName' => $this->exporterName,
+			'availableExporters' => $this->exporters,
+			'supportedData' => $this->supportedData,
+			'selectedData' => $this->selectedData,
+			'dbHost' => $this->dbHost,
+			'dbUser' => $this->dbUser,
+			'dbPassword' => $this->dbPassword,
+			'dbName' => $this->dbName,
+			'dbPrefix' => $this->dbPrefix,
+			'fileSystemPath' => $this->fileSystemPath
+		));
+	}
+}
diff --git a/wcfsetup/install/files/lib/data/user/group/UserGroupAction.class.php b/wcfsetup/install/files/lib/data/user/group/UserGroupAction.class.php
index e0c969c23e..9a8995becc 100644
--- a/wcfsetup/install/files/lib/data/user/group/UserGroupAction.class.php
+++ b/wcfsetup/install/files/lib/data/user/group/UserGroupAction.class.php
@@ -39,8 +39,10 @@ class UserGroupAction extends AbstractDatabaseObjectAction {
 	public function create() {
 		$group = parent::create();
 		
-		$groupEditor = new UserGroupEditor($group);
-		$groupEditor->updateGroupOptions($this->parameters['options']);
+		if (isset($this->parameters['options'])) {
+			$groupEditor = new UserGroupEditor($group);
+			$groupEditor->updateGroupOptions($this->parameters['options']);
+		}
 		
 		return $group;
 	}
diff --git a/wcfsetup/install/files/lib/system/exporter/AbstractExporter.class.php b/wcfsetup/install/files/lib/system/exporter/AbstractExporter.class.php
new file mode 100644
index 0000000000..5b901c8b30
--- /dev/null
+++ b/wcfsetup/install/files/lib/system/exporter/AbstractExporter.class.php
@@ -0,0 +1,143 @@
+<?php
+namespace wcf\system\exporter;
+use wcf\system\database\DatabaseException;
+use wcf\system\database\MySQLDatabase;
+use wcf\system\exception\SystemException;
+use wcf\util\FileUtil;
+
+/**
+ * Basic implementation of IExporter.
+ *
+ * @author	Marcel Werk
+ * @copyright	2001-2013 WoltLab GmbH
+ * @license	GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
+ * @package	com.woltlab.wcf
+ * @subpackage	system.exporter
+ * @category	Community Framework
+ */
+abstract class AbstractExporter implements IExporter {
+	/**
+	 * database host name
+	 * @var string
+	 */
+	protected $databaseHost = '';
+	
+	/**
+	 * database username
+	 * @var string
+	 */
+	protected $databaseUser = '';
+	
+	/**
+	 * database password
+	 * @var string
+	 */
+	protected $databasePassword = '';
+	
+	/**
+	 * database name
+	 * @var string
+	 */
+	protected $databaseName = '';
+	
+	/**
+	 * table prefix
+	 * @var string
+	 */
+	protected $databasePrefix = '';
+	
+	/**
+	 * file system path
+	 * @var string
+	 */
+	protected $fileSystemPath = '';
+	
+	/**
+	 * database connection
+	 * @var wcf\system\database\Database
+	 */
+	protected $database = null;
+	
+	/**
+	 * object type => method names
+	 * @var array
+	 */
+	protected $methods = array();
+	
+	/**
+	 * limits for items per run
+	 * @var array<integer>
+	 */
+	protected $limits = array();
+	
+	/**
+	 * default limit for items per run
+	 * @var integer
+	 */
+	protected $defaultLimit = 1000;
+	
+	/**
+	 * @see wcf\system\exporter\IExporter::setData()
+	 */
+	public function setData($databaseHost, $databaseUser, $databasePassword, $databaseName, $databasePrefix, $fileSystemPath) {
+		$this->databaseHost = $databaseHost;
+		$this->databaseUser = $databaseUser;
+		$this->databasePassword = $databasePassword;
+		$this->databaseName = $databaseName;
+		$this->databasePrefix = $databasePrefix;
+		$this->fileSystemPath = ($fileSystemPath ? FileUtil::addTrailingSlash($fileSystemPath) : '');
+	}
+	
+	/**
+	 * @see wcf\system\exporter\IExporter::init()
+	 */
+	public function init() {
+		$this->database = new MySQLDatabase($this->databaseHost, $this->databaseUser, $this->databasePassword, $this->databaseName, 0);
+	}
+	
+	/**
+	 * @see wcf\system\exporter\IExporter::validateDatabaseAccess()
+	 */
+	public function validateDatabaseAccess() {
+		try {
+			$this->init();
+		}
+		catch (DatabaseException $e) {
+			return false;
+		}
+		
+		return true;
+	}
+	
+	/**
+	 * @see wcf\system\exporter\IExporter::getDefaultDatabasePrefix()
+	 */
+	public function getDefaultDatabasePrefix() {
+		return '';
+	}
+	
+	/**
+	 * @see wcf\system\exporter\IExporter::countLoops()
+	 */
+	public function countLoops($objectType) {
+		if (!isset($this->methods[$objectType]) || !method_exists($this, 'count'.$this->methods[$objectType])) {
+			throw new SystemException("unknown object type '".$objectType."' given");
+		}
+		
+		$count = call_user_func(array($this, 'count'.$this->methods[$objectType]));
+		$limit = (isset($this->limits[$objectType]) ? $this->limits[$objectType] : $this->defaultLimit);
+		return ceil($count / $limit);
+	}
+	
+	/**
+	 * @see wcf\system\exporter\IExporter::exportData()
+	 */
+	public function exportData($objectType, $loopCount = 0) {
+		if (!isset($this->methods[$objectType]) || !method_exists($this, 'export'.$this->methods[$objectType])) {
+			throw new SystemException("unknown object type '".$objectType."' given");
+		}
+		
+		$limit = (isset($this->limits[$objectType]) ? $this->limits[$objectType] : $this->defaultLimit);
+		call_user_func(array($this, 'export'.$this->methods[$objectType]), $loopCount * $limit, $limit);
+	}
+}
diff --git a/wcfsetup/install/files/lib/system/exporter/IExporter.class.php b/wcfsetup/install/files/lib/system/exporter/IExporter.class.php
new file mode 100644
index 0000000000..fed6217f08
--- /dev/null
+++ b/wcfsetup/install/files/lib/system/exporter/IExporter.class.php
@@ -0,0 +1,90 @@
+<?php
+namespace wcf\system\exporter;
+
+/**
+ * Basic interface for all exporters.
+ *
+ * @author	Marcel Werk
+ * @copyright	2001-2013 WoltLab GmbH
+ * @license	GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
+ * @package	com.woltlab.wcf
+ * @subpackage	system.exporter
+ * @category	Community Framework
+ */
+interface IExporter {
+	/**
+	 * Sets database access data.
+	 * 
+	 * @param	string		$databaseHost
+	 * @param	string		$databaseUser
+	 * @param	string		$databasePassword
+	 * @param	string		$databaseName
+	 * @param	string		$databasePrefix
+	 * @param	string		$fileSystemPath
+	 */
+	public function setData($databaseHost, $databaseUser, $databasePassword, $databaseName, $databasePrefix, $fileSystemPath);
+	
+	/**
+	 * Initializes this exporter.
+	 */
+	public function init();
+	
+	/**
+	 * Counts the number of required loops for given type.
+	 * 
+	 * @param	string		$objectType
+	 * @return	integer
+	 */
+	public function countLoops($objectType);
+	
+	/**
+	 * Runs the data export.
+	 *
+	 * @param	string		$objectType
+	 * @param	integer		$loopCount
+	 */
+	public function exportData($objectType, $loopCount = 0);
+	
+	/**
+	 * Validates database access. Returns false on failure.
+	 *
+	 * @return	boolean
+	 */
+	public function validateDatabaseAccess();
+	
+	/**
+	 * Validates given file system path. Returns false on failure.
+	 *
+	 * @return	boolean
+	 */
+	public function validateFileAccess();
+	
+	/**
+	 * Validates the selected data types. Returns false on failure.
+	 * 
+	 * @param	array		$selectedData
+	 * @return	boolean
+	 */
+	public function validateSelectedData(array $selectedData);
+	
+	/**
+	 * Returns the import worker queue.
+	 * 
+	 * @return	array
+	 */
+	public function getQueue();
+	
+	/**
+	 * Returns the supported data types.
+	 * 
+	 * @return	array<string>
+	 */
+	public function getSupportedData();
+	
+	/**
+	 * Returns a default database table prefix.
+	 * 
+	 * @return	string
+	 */
+	public function getDefaultDatabasePrefix();
+}
diff --git a/wcfsetup/install/files/lib/system/importer/IImporter.class.php b/wcfsetup/install/files/lib/system/importer/IImporter.class.php
new file mode 100644
index 0000000000..a7a1d2a423
--- /dev/null
+++ b/wcfsetup/install/files/lib/system/importer/IImporter.class.php
@@ -0,0 +1,23 @@
+<?php
+namespace wcf\system\importer;
+
+/**
+ * Basic interface for all importer.
+ *
+ * @author	Marcel Werk
+ * @copyright	2001-2013 WoltLab GmbH
+ * @license	GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
+ * @package	com.woltlab.wcf
+ * @subpackage	system.importer
+ * @category	Community Framework
+ */
+interface IImporter {
+	/**
+	 * Imports a data set.
+	 * 
+	 * @param	mixed		$oldID
+	 * @param	array		$data
+	 * @return	mixed		new id
+	 */
+	public function import($oldID, array $data);
+}
diff --git a/wcfsetup/install/files/lib/system/importer/ImportHandler.class.php b/wcfsetup/install/files/lib/system/importer/ImportHandler.class.php
new file mode 100644
index 0000000000..e461484950
--- /dev/null
+++ b/wcfsetup/install/files/lib/system/importer/ImportHandler.class.php
@@ -0,0 +1,106 @@
+<?php
+namespace wcf\system\importer;
+use wcf\data\object\type\ObjectTypeCache;
+use wcf\system\exception\SystemException;
+use wcf\system\SingletonFactory;
+use wcf\system\WCF;
+
+/**
+ * Handles data import.
+ *
+ * @author	Marcel Werk
+ * @copyright	2001-2013 WoltLab GmbH
+ * @license	GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
+ * @package	com.woltlab.wcf
+ * @subpackage	system.importer
+ * @category	Community Framework
+ */
+class ImportHandler extends SingletonFactory {
+	/**
+	 * id map cache
+	 * @var	array 
+	 */
+	protected $idMappingCache = array();
+	
+	/**
+	 * list of available importers
+	 * @var array
+	 */
+	protected $objectTypes = array();
+	
+	/**
+	 * list of available importer processors
+	 * @var array
+	 */
+	protected $importers = array();
+	
+	/**
+	 * @see wcf\system\SingletonFactory::init()
+	 */
+	protected function init() {
+		$this->objectTypes = ObjectTypeCache::getInstance()->getObjectTypes('com.woltlab.wcf.importer');
+	}
+	
+	/**
+	 * Gets a data importer.
+	 * 
+	 * @param	string		$type
+	 * @return	wcf\system\importer\IImporter
+	 */
+	public function getImporter($type) {
+		if (!isset($this->importers[$type])) {
+			if (!isset($this->objectTypes[$type])) {
+				throw new SystemException("unknown importer '".$type."'");
+			}
+			
+			$this->importers[$type] = $this->objectTypes[$type]->getProcessor();
+		}
+		
+		return $this->importers[$type];
+	}
+	
+	/**
+	 * Gets a new id from id mapping.
+	 *
+	 * @param	string		$type
+	 * @param	mixed		$oldID
+	 * @return	integer		$newID
+	 */
+	public function getNewID($type, $oldID) {
+		$objectTypeID = $this->objectTypes[$type]->objectTypeID;
+		
+		if (!isset($this->idMappingCache[$objectTypeID][$oldID])) {
+			$this->idMappingCache[$objectTypeID][$oldID] = 0;
+			
+			$sql = "SELECT	newID
+				FROM	wcf".WCF_N."_import_mapping
+				WHERE	objectTypeID = ?
+					AND oldID = ?";
+			$statement = WCF::getDB()->prepareStatement($sql);
+			$statement->execute(array($objectTypeID, $oldID));
+			$row = $statement->fetchArray();
+			if ($row !== false) $this->idMappingCache[$objectTypeID][$oldID] = $row['newID'];
+		}
+		
+		return $this->idMappingCache[$objectTypeID][$oldID];
+	}
+	
+	/**
+	 * Saves an id mapping.
+	 *
+	 * @param	string		$type
+	 * @param	integer		$oldID
+	 * @param	integer		$newID
+	 */
+	public function saveNewID($type, $oldID, $newID) {
+		$objectTypeID = $this->objectTypes[$type]->objectTypeID;
+		
+		$sql = "INSERT IGNORE INTO	wcf".WCF_N."_import_mapping
+						(objectTypeID, oldID, newID)
+			VALUES			(?, ?, ?)";
+		$statement = WCF::getDB()->prepareStatement($sql);
+		$statement->execute(array($objectTypeID, $oldID, $newID));
+		
+		unset($this->idMappingCache[$objectTypeID][$oldID]);
+	}
+}
diff --git a/wcfsetup/install/files/lib/system/importer/UserGroupImporter.class.php b/wcfsetup/install/files/lib/system/importer/UserGroupImporter.class.php
new file mode 100644
index 0000000000..254307a5a0
--- /dev/null
+++ b/wcfsetup/install/files/lib/system/importer/UserGroupImporter.class.php
@@ -0,0 +1,30 @@
+<?php
+namespace wcf\system\importer;
+use wcf\data\user\group\UserGroupAction;
+
+/**
+ * Imports user groups.
+ *
+ * @author	Marcel Werk
+ * @copyright	2001-2013 WoltLab GmbH
+ * @license	GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
+ * @package	com.woltlab.wcf
+ * @subpackage	system.importer
+ * @category	Community Framework
+ */
+class UserGroupImporter implements IImporter {
+	/**
+	 * @see wcf\system\importer::import()
+	 */
+	public function import($oldID, array $data) {
+		$action = new UserGroupAction(array(), 'create', array(
+			'data' => $data		
+		));
+		$returnValues = $action->executeAction();
+		$newGroupID = $returnValues['returnValues']->groupID;
+		
+		ImportHandler::getInstance()->saveNewID('com.woltlab.wcf.user.group', $oldID, $newGroupID);
+		
+		return $newGroupID;
+	}
+}
diff --git a/wcfsetup/install/files/lib/system/importer/UserImporter.class.php b/wcfsetup/install/files/lib/system/importer/UserImporter.class.php
new file mode 100644
index 0000000000..ac5764d279
--- /dev/null
+++ b/wcfsetup/install/files/lib/system/importer/UserImporter.class.php
@@ -0,0 +1,40 @@
+<?php
+namespace wcf\system\importer;
+use wcf\data\user\UserAction;
+use wcf\system\database\DatabaseException;
+use wcf\system\WCF;
+
+/**
+ * Imports users.
+ *
+ * @author	Marcel Werk
+ * @copyright	2001-2013 WoltLab GmbH
+ * @license	GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
+ * @package	com.woltlab.wcf
+ * @subpackage	system.importer
+ * @category	Community Framework
+ */
+class UserImporter implements IImporter {
+	/**
+	 * @see wcf\system\importer::import()
+	 */
+	public function import($oldID, array $data) {
+		$sql = "SELECT	COUNT(*) AS count
+			FROM	wcf".WCF_N."_user
+			WHERE	userID = ?";
+		$statement = WCF::getDB()->prepareStatement($sql);
+		$statement->execute(array($oldID));
+		$row = $statement->fetchArray();
+		if (!$row['count']) $data['userID'] = $oldID;
+		
+		$action = new UserAction(array(), 'create', array(
+			'data' => $data
+		));
+		$returnValues = $action->executeAction();
+		
+		$newUserID = $returnValues['returnValues']->groupID;
+		ImportHandler::getInstance()->saveNewID('com.woltlab.wcf.user', $oldID, $newUserID);
+		
+		return $newUserID;
+	}
+}
diff --git a/wcfsetup/install/files/lib/system/worker/ImportWorker.class.php b/wcfsetup/install/files/lib/system/worker/ImportWorker.class.php
new file mode 100644
index 0000000000..6176b07094
--- /dev/null
+++ b/wcfsetup/install/files/lib/system/worker/ImportWorker.class.php
@@ -0,0 +1,93 @@
+<?php
+namespace wcf\system\worker;
+use wcf\data\object\type\ObjectTypeCache;
+use wcf\system\exception\SystemException;
+use wcf\system\WCF;
+
+/**
+ * Worker implementation for data import.
+ * 
+ * @author	Marcel Werk
+ * @copyright	2001-2013 WoltLab GmbH
+ * @license	GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
+ * @package	com.woltlab.wcf
+ * @subpackage	system.worker
+ * @category	Community Framework
+ */
+class ImportWorker extends AbstractWorker {
+	/**
+	 * import data
+	 * @var	array
+	 */
+	protected $importData = null;
+	
+	/**
+	 * exporter object
+	 * @var wcf\system\exporter\IExporter
+	 */
+	protected $exporter = null;
+	
+	/**
+	 * @see	wcf\system\worker\IWorker::validate()
+	 */
+	public function validate() {
+		WCF::getSession()->checkPermissions(array('admin.system.canImportData'));
+		
+		if (!isset($this->parameters['objectType'])) {
+			throw new SystemException("parameter 'objectType' missing");
+		}
+		
+		// get import data
+		$this->importData = WCF::getSession()->getVar('importData');
+		if ($this->importData === null) {
+			throw new SystemException("import data missing");
+		}
+		
+		// get exporter
+		$this->exporter = ObjectTypeCache::getInstance()->getObjectTypeByName('com.woltlab.wcf.exporter', $this->importData['exporterName'])->getProcessor();
+		
+		// set data
+		$this->exporter->setData($this->importData['dbHost'], $this->importData['dbUser'], $this->importData['dbPassword'], $this->importData['dbName'], $this->importData['dbPrefix'], $this->importData['fileSystemPath']);
+		$this->exporter->init();
+	}
+	
+	/**
+	 * @see	wcf\system\worker\AbstractWorker::countObjects()
+	 */
+	protected function countObjects() {
+		$this->count = $this->exporter->countLoops($this->parameters['objectType']);
+	}
+	
+	/**
+	 * @see	wcf\system\worker\IWorker::getProgress()
+	 */
+	public function getProgress() {
+		$this->countObjects();
+		
+		if (!$this->count) {
+			return 100;
+		}
+		
+		$progress = (($this->loopCount + 1) / $this->count) * 100;
+		if ($progress > 100) $progress = 100;
+		return round($progress, 0);
+	}
+	
+	/**
+	 * @see	wcf\system\worker\IWorker::execute()
+	 */
+	public function execute() {
+		if (!$this->count) {
+			return;
+		}
+
+		$this->exporter->exportData($this->parameters['objectType'], $this->loopCount);
+	}
+	
+	/**
+	 * @see	wcf\system\worker\IWorker::getProceedURL()
+	 */
+	public function getProceedURL() {
+		return '';
+	}
+}
diff --git a/wcfsetup/setup/db/install.sql b/wcfsetup/setup/db/install.sql
index 12905005a4..f8a67d2e20 100644
--- a/wcfsetup/setup/db/install.sql
+++ b/wcfsetup/setup/db/install.sql
@@ -326,6 +326,14 @@ CREATE TABLE wcf1_event_listener (
 	UNIQUE KEY packageID (packageID, environment, eventClassName, eventName, listenerClassName)
 );
 
+DROP TABLE IF EXISTS wcf1_import_mapping;
+CREATE TABLE wcf1_import_mapping (
+	objectTypeID INT(10) NOT NULL,
+	oldID VARCHAR(255) NOT NULL,
+	newID INT(10) NOT NULL,
+	UNIQUE KEY (objectTypeID, oldID)
+);
+
 DROP TABLE IF EXISTS wcf1_label;
 CREATE TABLE wcf1_label (
 	labelID INT(10) NOT NULL AUTO_INCREMENT PRIMARY KEY,
@@ -1433,6 +1441,8 @@ ALTER TABLE wcf1_dashboard_box ADD FOREIGN KEY (packageID) REFERENCES wcf1_packa
 ALTER TABLE wcf1_dashboard_option ADD FOREIGN KEY (objectTypeID) REFERENCES wcf1_object_type (objectTypeID) ON DELETE CASCADE;
 ALTER TABLE wcf1_dashboard_option ADD FOREIGN KEY (boxID) REFERENCES wcf1_dashboard_box (boxID) ON DELETE CASCADE;
 
+ALTER TABLE wcf1_import_mapping ADD FOREIGN KEY (objectTypeID) REFERENCES wcf1_object_type (objectTypeID) ON DELETE CASCADE;
+
 ALTER TABLE wcf1_tracked_visit ADD FOREIGN KEY (objectTypeID) REFERENCES wcf1_object_type (objectTypeID) ON DELETE CASCADE;
 ALTER TABLE wcf1_tracked_visit ADD FOREIGN KEY (userID) REFERENCES wcf1_user (userID) ON DELETE CASCADE;
 
-- 
2.20.1