From: Marcel Werk <burntime@woltlab.com>
Date: Mon, 20 May 2013 22:23:22 +0000 (+0200)
Subject: Merged com.woltlab.wcf.like into WCF
X-Git-Tag: 2.0.0_Beta_1~126
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=00b6f9566682480ad92c0f81d64ee913410b6f1b;p=GitHub%2FWoltLab%2FWCF.git

Merged com.woltlab.wcf.like into WCF
---

diff --git a/com.woltlab.wcf/dashboardBox.xml b/com.woltlab.wcf/dashboardBox.xml
index 226ab83a9c..e7ce58956a 100644
--- a/com.woltlab.wcf/dashboardBox.xml
+++ b/com.woltlab.wcf/dashboardBox.xml
@@ -35,5 +35,10 @@
 			<classname><![CDATA[wcf\system\dashboard\box\MostActiveMembersDashboardBox]]></classname>
 			<boxtype>sidebar</boxtype>
 		</dashboardbox>
+		
+		<dashboardbox name="com.woltlab.wcf.like.mostLikedMembers">
+			<classname><![CDATA[wcf\system\dashboard\box\MostLikedMembersDashboardBox]]></classname>
+			<boxtype>sidebar</boxtype>
+		</dashboardbox>
 	</import>
 </data>
diff --git a/com.woltlab.wcf/objectType.xml b/com.woltlab.wcf/objectType.xml
index 2e628f4653..dca396a5f8 100644
--- a/com.woltlab.wcf/objectType.xml
+++ b/com.woltlab.wcf/objectType.xml
@@ -139,5 +139,14 @@
 			<classname>wcf\system\moderation\queue\ModerationQueueReportManager</classname>
 		</type>
 		<!-- /moderation type -->
+		
+		<!-- activity points -->
+		<type>
+			<name>com.woltlab.wcf.like.activityPointEvent.receivedLikes</name>
+			<definitionname>com.woltlab.wcf.user.activityPointEvent</definitionname>
+			<points>1</points>
+			<classname>wcf\system\user\activity\point\ReceivedLikesUserActivityPointObjectProcessor</classname>
+		</type>
+		<!-- /activity points -->
 	</import>
 </data>
\ No newline at end of file
diff --git a/com.woltlab.wcf/objectTypeDefinition.xml b/com.woltlab.wcf/objectTypeDefinition.xml
index 57f677e7fd..94cd667e7f 100644
--- a/com.woltlab.wcf/objectTypeDefinition.xml
+++ b/com.woltlab.wcf/objectTypeDefinition.xml
@@ -89,5 +89,10 @@
 			<name>com.woltlab.wcf.moderation.report</name>
 			<interfacename>wcf\system\moderation\queue\report\IModerationQueueReportHandler</interfacename>
 		</definition>
+		
+		<definition>
+			<name>com.woltlab.wcf.like.likeableObject</name>
+			<interfacename>wcf\data\like\ILikeObjectTypeProvider</interfacename>
+		</definition>
 	</import>
 </data>
diff --git a/com.woltlab.wcf/option.xml b/com.woltlab.wcf/option.xml
index 0a96fccc48..cf426faa96 100644
--- a/com.woltlab.wcf/option.xml
+++ b/com.woltlab.wcf/option.xml
@@ -165,6 +165,9 @@
 					<category name="message.general.share">
 						<parent>message.general</parent>
 					</category>
+					<category name="message.general.likes">
+						<parent>message.general</parent>
+					</category>
 				
 				<category name="message.attachment">
 					<parent>message</parent>
@@ -278,6 +281,12 @@
 				<defaultvalue>1</defaultvalue>
 			</option>
 			
+			<option name="module_like">
+				<categoryname>module.community</categoryname>
+				<optiontype>boolean</optiontype>
+				<defaultvalue>1</defaultvalue>
+			</option>
+			
 			<!-- general.page -->
 			<option name="page_title">
 				<categoryname>general.page</categoryname>
@@ -849,7 +858,8 @@ no:!cache_source_memcached_host]]></enableoptions>
 				<defaultvalue><![CDATA[username]]></defaultvalue>
 				<selectoptions><![CDATA[username:wcf.user.username
 registrationDate:wcf.user.registrationDate
-activityPoints:wcf.user.activityPoint]]></selectoptions>
+activityPoints:wcf.user.activityPoint
+likedReceived:wcf.like.likesReceived]]></selectoptions>
 			</option>
 			<option name="members_list_default_sort_order">
 				<categoryname>user.list.members</categoryname>
@@ -928,6 +938,27 @@ DESC:wcf.global.sortOrder.descending]]></selectoptions>
 				<defaultvalue>5</defaultvalue>
 			</option>
 			<!-- /dashboard -->
+			
+			<option name="like_allow_for_own_content">
+				<categoryname>message.general.likes</categoryname>
+				<optiontype>boolean</optiontype>
+				<defaultvalue>1</defaultvalue>
+				<options>module_like</options>
+			</option>
+			
+			<option name="like_enable_dislike">
+				<categoryname>message.general.likes</categoryname>
+				<optiontype>boolean</optiontype>
+				<defaultvalue>1</defaultvalue>
+				<options>module_like</options>
+			</option>
+			
+			<option name="like_show_summary">
+				<categoryname>message.general.likes</categoryname>
+				<optiontype>boolean</optiontype>
+				<defaultvalue>1</defaultvalue>
+				<options>module_like</options>
+			</option>
 		</options>
 	</import>
 </data>
diff --git a/com.woltlab.wcf/template/dashboardBoxMostLikedMembers.tpl b/com.woltlab.wcf/template/dashboardBoxMostLikedMembers.tpl
new file mode 100644
index 0000000000..20b55ba98a
--- /dev/null
+++ b/com.woltlab.wcf/template/dashboardBoxMostLikedMembers.tpl
@@ -0,0 +1,12 @@
+<ul class="sidebarBoxList">
+	{foreach from=$mostLikedMembers item=likedMember}
+		<li class="box24">
+			<a href="{link controller='User' object=$likedMember}{/link}" class="framed">{@$likedMember->getAvatar()->getImageTag(24)}</a>
+			
+			<div class="sidebarBoxHeadline">
+				<h3><a href="{link controller='User' object=$likedMember}{/link}" class="userLink" data-user-id="{@$likedMember->userID}">{$likedMember->username}</a></h3>
+				<small>{lang}wcf.dashboard.box.mostLikedMembers.likes{/lang}</small>
+			</div>
+		</li>
+	{/foreach}
+</ul>
diff --git a/com.woltlab.wcf/template/headInclude.tpl b/com.woltlab.wcf/template/headInclude.tpl
index 4f8eaa537c..199f089104 100644
--- a/com.woltlab.wcf/template/headInclude.tpl
+++ b/com.woltlab.wcf/template/headInclude.tpl
@@ -45,6 +45,7 @@
 </script>
 <script type="text/javascript" src="{@$__wcf->getPath()}js/WCF.Message{if !ENABLE_DEBUG_MODE}.min{/if}.js"></script>
 <script type="text/javascript" src="{@$__wcf->getPath()}js/WCF.User{if !ENABLE_DEBUG_MODE}.min{/if}.js"></script>
+<script type="text/javascript" src="{@$__wcf->getPath('wcf')}js/WCF.Like{if !ENABLE_DEBUG_MODE}.min{/if}.js"></script>
 {event name='javascriptInclude'}
 
 <!-- Stylesheets -->
@@ -116,6 +117,14 @@
 			'wcf.global.thousandsSeparator': '{capture assign=thousandsSeparator}{lang}wcf.global.thousandsSeparator{/lang}{/capture}{@$thousandsSeparator|encodeJS}',
 			'wcf.page.sitemap': '{lang}wcf.page.sitemap{/lang}',
 			'wcf.style.changeStyle': '{lang}wcf.style.changeStyle{/lang}'
+			{if MODULE_LIKE}
+				,'wcf.like.button.like': '{lang}wcf.like.button.like{/lang}',
+				'wcf.like.button.dislike': '{lang}wcf.like.button.dislike{/lang}',
+				'wcf.like.tooltip': '{lang}wcf.like.jsTooltip{/lang}',
+				'wcf.like.summary': '{lang}wcf.like.summary{/lang}',
+				'wcf.like.details': '{lang}wcf.like.details{/lang}'
+			{/if}
+			
 			{event name='javascriptLanguageImport'}
 		});
 		
diff --git a/com.woltlab.wcf/template/membersList.tpl b/com.woltlab.wcf/template/membersList.tpl
index 4f947c4ddb..91cd06673e 100644
--- a/com.woltlab.wcf/template/membersList.tpl
+++ b/com.woltlab.wcf/template/membersList.tpl
@@ -76,6 +76,7 @@
 							<option value="username"{if $sortField == 'username'} selected="selected"{/if}>{lang}wcf.user.username{/lang}</option>
 							<option value="registrationDate"{if $sortField == 'registrationDate'} selected="selected"{/if}>{lang}wcf.user.registrationDate{/lang}</option>
 							<option value="activityPoints"{if $sortField == 'activityPoints'} selected="selected"{/if}>{lang}wcf.user.activityPoint{/lang}</option>
+							<option value="likesReceived"{if $sortField == 'likesReceived'} selected="selected"{/if}>{lang}wcf.like.likesReceived{/lang}</option>
 							{event name='sortField'}
 						</select>
 						<select name="sortOrder">
diff --git a/com.woltlab.wcf/template/userInformationStatistics.tpl b/com.woltlab.wcf/template/userInformationStatistics.tpl
index bc1a9fbefb..b8bb82be5c 100644
--- a/com.woltlab.wcf/template/userInformationStatistics.tpl
+++ b/com.woltlab.wcf/template/userInformationStatistics.tpl
@@ -1,6 +1,11 @@
 <dl class="plain inlineDataList userStats">
 	{event name='statistics'}
 	
+	{if MODULE_LIKE}
+		<dt>{lang}wcf.like.likesReceived{/lang}</dt>
+		<dd>{#$user->likesReceived}</dd>
+	{/if}
+	
 	<dt>{lang}wcf.user.activityPoint{/lang}</dt>
 	<dd>{#$user->activityPoints}</dd>
 </dl>
\ No newline at end of file
diff --git a/com.woltlab.wcf/template/userSidebar.tpl b/com.woltlab.wcf/template/userSidebar.tpl
index 40b7e83099..11458b6e16 100644
--- a/com.woltlab.wcf/template/userSidebar.tpl
+++ b/com.woltlab.wcf/template/userSidebar.tpl
@@ -16,6 +16,11 @@
 	<dl class="plain statsDataList">
 		{event name='statistics'}
 		
+		{if MODULE_LIKE}
+			<dt>{lang}wcf.like.likesReceived{/lang}</dt>
+			<dd>{#$user->likesReceived}</dd>
+		{/if}
+		
 		<dt>{if $user->activityPoints}<a class="activityPointsDisplay jsTooltip" title="{lang}wcf.user.activityPoint.showDetails{/lang}" data-user-id="{@$user->userID}">{lang}wcf.user.activityPoint{/lang}</a>{else}{lang}wcf.user.activityPoint{/lang}{/if}</dt>
 		<dd>{#$user->activityPoints}</dd>
 		
diff --git a/com.woltlab.wcf/userGroupOption.xml b/com.woltlab.wcf/userGroupOption.xml
index d18ab007d7..50bcbbf3ff 100644
--- a/com.woltlab.wcf/userGroupOption.xml
+++ b/com.woltlab.wcf/userGroupOption.xml
@@ -6,6 +6,9 @@
 			<category name="user.message">
 				<parent>user</parent>
 			</category>
+			<category name="user.like">
+				<parent>user.message</parent>
+			</category>
 			<category name="user.message.attachment">
 				<parent>user.message</parent>
 			</category>
@@ -473,6 +476,17 @@ png]]></defaultvalue>
 				<defaultvalue>0</defaultvalue>
 				<admindefaultvalue>1</admindefaultvalue>
 			</option>
+			
+			<option name="user.like.canViewLike">
+				<categoryname>user.like</categoryname>
+				<optiontype>boolean</optiontype>
+				<defaultvalue>1</defaultvalue>
+			</option>
+			<option name="user.like.canLike">
+				<categoryname>user.like</categoryname>
+				<optiontype>boolean</optiontype>
+				<defaultvalue>1</defaultvalue>
+			</option>
 		</options>
 	</import>
 </data>
diff --git a/wcfsetup/install/files/js/WCF.Like.js b/wcfsetup/install/files/js/WCF.Like.js
new file mode 100644
index 0000000000..714cf1d854
--- /dev/null
+++ b/wcfsetup/install/files/js/WCF.Like.js
@@ -0,0 +1,433 @@
+/**
+ * Like support for WCF
+ * 
+ * @author	Alexander Ebert
+ * @copyright	2001-2013 WoltLab GmbH
+ * @license	GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
+ */
+WCF.Like = Class.extend({
+	/**
+	 * true, if users can like their own content
+	 * @var	boolean
+	 */
+	_allowForOwnContent: false,
+	
+	/**
+	 * user can like 
+	 * @var	boolean
+	 */
+	_canLike: false,
+	
+	/**
+	 * list of containers
+	 * @var	object
+	 */
+	_containers: { },
+	
+	/**
+	 * container meta data
+	 * @var	object
+	 */
+	_containerData: { },
+	
+	/**
+	 * enables the dislike option
+	 */
+	_enableDislikes: true,
+	
+	/**
+	 * prevents like/dislike until the server responded
+	 * @var	boolean
+	 */
+	_isBusy: false,
+	
+	/**
+	 * cached template for like details
+	 * @var	object
+	 */
+	_likeDetails: { },
+	
+	/**
+	 * dialog overlay for like details
+	 * @var	jQuery
+	 */
+	_likeDetailsDialog: null,
+	
+	/**
+	 * proxy object
+	 * @var	WCF.Action.Proxy
+	 */
+	_proxy: null,
+	
+	/**
+	 * shows the detailed summary of users who liked the object
+	 */
+	_showSummary: true,
+	
+	/**
+	 * Initializes like support.
+	 * 
+	 * @param	boolean		canLike
+	 * @param	boolean		enableDislikes
+	 * @param	boolean		showSummary
+	 * @param	boolean		allowForOwnContent
+	 */
+	init: function(canLike, enableDislikes, showSummary, allowForOwnContent) {
+		this._canLike = canLike;
+		this._enableDislikes = enableDislikes;
+		this._isBusy = false;
+		this._likeDetails = { };
+		this._likeDetailsDialog = null;
+		this._showSummary = showSummary;
+		this._allowForOwnContent = allowForOwnContent;
+		
+		var $containers = this._getContainers();
+		this._initContainers($containers);
+		
+		this._proxy = new WCF.Action.Proxy({
+			success: $.proxy(this._success, this)
+		});
+		
+		// bind dom node inserted listener
+		var $date = new Date();
+		var $identifier = $date.toString().hashCode + $date.getUTCMilliseconds();
+		WCF.DOMNodeInsertedHandler.addCallback('WCF.Like' + $identifier, $.proxy(this._domNodeInserted, this));
+	},
+	
+	/**
+	 * Initialize containers once new nodes are inserted.
+	 */
+	_domNodeInserted: function() {
+		var $containers = this._getContainers();
+		this._initContainers($containers);
+		
+	},
+	
+	/**
+	 * Initializes like containers.
+	 * 
+	 * @param	object		containers
+	 */
+	_initContainers: function(containers) {
+		var $createdWidgets = false;
+		containers.each($.proxy(function(index, container) {
+			// set container
+			var $container = $(container);
+			var $containerID = $container.wcfIdentify();
+			
+			if (!this._containers[$containerID]) {
+				this._containers[$containerID] = $container;
+				
+				// set container data
+				this._containerData[$containerID] = {
+					'likeButton': null,
+					'badge': null,
+					'dislikeButton': null,
+					'likes': $container.data('like-likes'),
+					'dislikes': $container.data('like-dislikes'),
+					'objectType': $container.data('objectType'),
+					'objectID': this._getObjectID($containerID),
+					'users': eval($container.data('like-users')),
+					'liked': $container.data('like-liked')
+				};
+				
+				// create UI
+				this._createWidget($containerID);
+				
+				$createdWidgets = true;
+			}
+		}, this));
+		
+		if ($createdWidgets) {
+			new WCF.PeriodicalExecuter(function(pe) {
+				pe.stop();
+				
+				WCF.DOMNodeInsertedHandler.forceExecution();
+			}, 250);
+		}
+	},
+	
+	/**
+	 * Returns a list of available object containers.
+	 * 
+	 * @return	jQuery
+	 */
+	_getContainers: function() { },
+	
+	/**
+	 * Returns widget container for target object container.
+	 * 
+	 * @param	string		containerID
+	 * @return	jQuery
+	 */
+	_getWidgetContainer: function(containerID) { },
+	
+	/**
+	 * Returns object id for targer object container.
+	 * 
+	 * @param	string		containerID
+	 * @return	integer
+	 */
+	_getObjectID: function(containerID) { },
+	
+	/**
+	 * Adds the like widget.
+	 * 
+	 * @param	integer		containerID
+	 * @param	jQuery		widget
+	 */
+	_addWidget: function(containerID, widget) {
+		var $widgetContainer = this._getWidgetContainer(containerID);
+		
+		widget.appendTo($widgetContainer);
+	},
+	
+	/**
+	 * Builds the like widget.
+	 * 
+	 * @param	integer		containerID
+	 * @param	jQuery		likeButton
+	 * @param	jQuery		dislikeButton
+	 * @param	jQuery		badge
+	 * @param	jQuery		summary
+	 */
+	_buildWidget: function(containerID, likeButton, dislikeButton, badge, summary) {
+		var $widget = $('<aside class="likesWidget"><ul></ul></aside>');
+		if (this._canLike) {
+			likeButton.appendTo($widget.find('ul'));
+			dislikeButton.appendTo($widget.find('ul'));
+		}
+		badge.appendTo($widget);
+		
+		this._addWidget(containerID, $widget); 
+	},
+	
+	/**
+	 * Creates the like widget.
+	 * 
+	 * @param	integer		containerID
+	 */
+	_createWidget: function(containerID) {
+		var $likeButton = $('<li class="likeButton"><a title="'+WCF.Language.get('wcf.like.button.like')+'" class="jsTooltip"><span class="icon icon16 icon-thumbs-up" /> <span class="invisible">'+WCF.Language.get('wcf.like.button.like')+'</span></a></li>');
+		var $dislikeButton = $('<li class="dislikeButton"><a title="'+WCF.Language.get('wcf.like.button.dislike')+'" class="jsTooltip"><span class="icon icon16 icon-thumbs-down" /> <span class="invisible">'+WCF.Language.get('wcf.like.button.dislike')+'</span></a></li>');
+		if (!this._enableDislikes) $dislikeButton.hide();
+		
+		if (!this._allowForOwnContent && (WCF.User.userID == this._containers[containerID].data('userID'))) {
+			$likeButton.hide();
+			$dislikeButton.hide();
+		}
+		
+		var $badge = $('<a class="badge jsTooltip likesBadge" />').data('containerID', containerID).click($.proxy(this._showLikeDetails, this));
+		
+		var $summary = null;
+		if (this._showSummary) {
+			$summary = $('<p class="likesSummary"><span class="pointer" /></p>');
+			$summary.children('span').data('containerID', containerID).click($.proxy(this._showLikeDetails, this));
+		}
+		this._buildWidget(containerID, $likeButton, $dislikeButton, $badge, $summary);
+		
+		this._containerData[containerID].likeButton = $likeButton;
+		this._containerData[containerID].dislikeButton = $dislikeButton;
+		this._containerData[containerID].badge = $badge;
+		this._containerData[containerID].summary = $summary;
+		
+		$likeButton.data('containerID', containerID).data('type', 'like').click($.proxy(this._click, this));
+		$dislikeButton.data('containerID', containerID).data('type', 'dislike').click($.proxy(this._click, this));
+		this._setActiveState($likeButton, $dislikeButton, this._containerData[containerID].liked);
+		this._updateBadge(containerID);
+		if (this._showSummary) this._updateSummary(containerID);
+	},
+	
+	/**
+	 * Displays like details for an object.
+	 * 
+	 * @param	object		event
+	 * @param	string		containerID
+	 */
+	_showLikeDetails: function(event, containerID) {
+		var $containerID = (event === null) ? containerID : $(event.currentTarget).data('containerID');
+		
+		if (this._likeDetails[$containerID] === undefined) {
+			this._proxy.setOption('data', {
+				actionName: 'getLikeDetails',
+				className: 'wcf\\data\\like\\LikeAction',
+				parameters: {
+					data: {
+						containerID: $containerID,
+						objectID: this._containerData[$containerID].objectID,
+						objectType: this._containerData[$containerID].objectType
+					}
+				}
+			});
+			this._proxy.sendRequest();
+		}
+		else {
+			if (this._likeDetailsDialog === null) {
+				this._likeDetailsDialog = $('<div>' + this._likeDetails[$containerID] + '</div>').hide().appendTo(document.body);
+				this._likeDetailsDialog.wcfDialog({
+					title: WCF.Language.get('wcf.like.details')
+				});
+			}
+			else {
+				this._likeDetailsDialog.html(this._likeDetails[$containerID]).wcfDialog('open');
+			}
+		}
+	},
+	
+	/**
+	 * Handles likes and dislikes.
+	 * 
+	 * @param	object		event
+	 */
+	_click: function(event) {
+		var $button = $(event.currentTarget);
+		if ($button === null) {
+			console.debug("[WCF.Like] Unable to find target button, aborting.");
+			return;
+		}
+		
+		this._sendRequest($button.data('containerID'), $button.data('type'));
+	},
+	
+	/**
+	 * Sends request through proxy.
+	 * 
+	 * @param	integer		containerID
+	 * @param	string		type
+	 */
+	_sendRequest: function(containerID, type) {
+		// ignore retards spamming clicks on the buttons
+		if (this._isBusy) {
+			return;
+		}
+		
+		this._proxy.setOption('data', {
+			actionName: type,
+			className: 'wcf\\data\\like\\LikeAction',
+			parameters: {
+				data: {
+					containerID: containerID,
+					objectID: this._containerData[containerID].objectID,
+					objectType: this._containerData[containerID].objectType
+				}
+			}
+		});
+		
+		this._proxy.sendRequest();
+	},
+	
+	/**
+	 * Updates likeable object.
+	 * 
+	 * @param	object		data
+	 * @param	string		textStatus
+	 * @param	object		jqXHR
+	 */
+	_success: function(data, textStatus, jqXHR) {
+		var $containerID = data.returnValues.containerID;
+		
+		if (!this._containers[$containerID]) {
+			return;
+		}
+		
+		switch (data.actionName) {
+			case 'dislike':
+			case 'like':
+				// update container data
+				this._containerData[$containerID].likes = parseInt(data.returnValues.likes);
+				this._containerData[$containerID].dislikes = parseInt(data.returnValues.dislikes);
+				this._containerData[$containerID].users = data.returnValues.users;
+				
+				// update label
+				this._updateBadge($containerID);
+				// update summary
+				if (this._showSummary) this._updateSummary($containerID);
+				
+				// mark button as active
+				var $likeButton = this._containerData[$containerID].likeButton;
+				var $dislikeButton = this._containerData[$containerID].dislikeButton;
+				var $likeStatus = 0;
+				if (data.returnValues.isLiked) $likeStatus = 1;
+				else if (data.returnValues.isDisliked) $likeStatus = -1;
+				this._setActiveState($likeButton, $dislikeButton, $likeStatus);
+				
+				// invalidate cache for like details
+				if (this._likeDetails[$containerID] !== undefined) {
+					delete this._likeDetails[$containerID];
+				}
+				
+				this._isBusy = false;
+			break;
+			
+			case 'getLikeDetails':
+				this._likeDetails[$containerID] = data.returnValues.template;
+				this._showLikeDetails(null, $containerID);
+			break;
+		}
+	},
+	
+	_updateBadge: function(containerID) {
+		if (!this._containerData[containerID].likes && !this._containerData[containerID].dislikes) {
+			this._containerData[containerID].badge.hide();
+		}
+		else {
+			this._containerData[containerID].badge.show();
+			
+			// update like counter
+			var $cumulativeLikes = this._containerData[containerID].likes - this._containerData[containerID].dislikes;
+			var $badge = this._containerData[containerID].badge;
+			$badge.removeClass('green red');
+			if ($cumulativeLikes > 0) {
+				$badge.text('+' + WCF.String.formatNumeric($cumulativeLikes));
+				$badge.addClass('green');
+			}
+			else if ($cumulativeLikes < 0) {
+				$badge.text(WCF.String.formatNumeric($cumulativeLikes));
+				$badge.addClass('red');
+			}
+			else {
+				$badge.text('\u00B10');
+			}
+			
+			// update tooltip
+			var $likes = this._containerData[containerID].likes;
+			var $dislikes = this._containerData[containerID].dislikes;
+			$badge.data('tooltip', eval(WCF.Language.get('wcf.like.tooltip')));
+		}
+	},
+	
+	_updateSummary: function(containerID) {
+		if (!this._containerData[containerID].likes) {
+			this._containerData[containerID].summary.hide();
+		}
+		else {
+			this._containerData[containerID].summary.show();
+			
+			var $users = this._containerData[containerID].users;
+			var $userArray = [];
+			for (var $userID in $users) $userArray.push($users[$userID].username);
+			var $others = this._containerData[containerID].likes - $userArray.length;
+			
+			this._containerData[containerID].summary.children('span').html(eval(WCF.Language.get('wcf.like.summary')));
+		}
+	},
+	
+	/**
+	 * Sets button active state.
+	 * 
+	 * @param 	jquery		likeButton
+	 * @param 	jquery		dislikeButton
+	 * @param	integer		likeStatus
+	 */
+	_setActiveState: function(likeButton, dislikeButton, likeStatus) {
+		likeButton.removeClass('active');
+		dislikeButton.removeClass('active');
+		
+		if (likeStatus == 1) {
+			likeButton.addClass('active');
+		}
+		else if (likeStatus == -1) {
+			dislikeButton.addClass('active');
+		}
+	}
+});
diff --git a/wcfsetup/install/files/js/WCF.Like.min.js b/wcfsetup/install/files/js/WCF.Like.min.js
new file mode 100644
index 0000000000..ae8b8606c7
--- /dev/null
+++ b/wcfsetup/install/files/js/WCF.Like.min.js
@@ -0,0 +1 @@
+WCF.Like=Class.extend({_allowForOwnContent:false,_canLike:false,_containers:{},_containerData:{},_enableDislikes:true,_isBusy:false,_likeDetails:{},_likeDetailsDialog:null,_proxy:null,_showSummary:true,init:function(a,c,f,e){this._canLike=a;this._enableDislikes=c;this._isBusy=false;this._likeDetails={};this._likeDetailsDialog=null;this._showSummary=f;this._allowForOwnContent=e;var d=this._getContainers();this._initContainers(d);this._proxy=new WCF.Action.Proxy({success:$.proxy(this._success,this)});var g=new Date();var b=g.toString().hashCode+g.getUTCMilliseconds();WCF.DOMNodeInsertedHandler.addCallback("WCF.Like"+b,$.proxy(this._domNodeInserted,this))},_domNodeInserted:function(){var a=this._getContainers();this._initContainers(a)},_initContainers:function(containers){var $createdWidgets=false;containers.each($.proxy(function(index,container){var $container=$(container);var $containerID=$container.wcfIdentify();if(!this._containers[$containerID]){this._containers[$containerID]=$container;this._containerData[$containerID]={likeButton:null,badge:null,dislikeButton:null,likes:$container.data("like-likes"),dislikes:$container.data("like-dislikes"),objectType:$container.data("objectType"),objectID:this._getObjectID($containerID),users:eval($container.data("like-users")),liked:$container.data("like-liked")};this._createWidget($containerID);$createdWidgets=true}},this));if($createdWidgets){new WCF.PeriodicalExecuter(function(pe){pe.stop();WCF.DOMNodeInsertedHandler.forceExecution()},250)}},_getContainers:function(){},_getWidgetContainer:function(a){},_getObjectID:function(a){},_addWidget:function(a,b){var c=this._getWidgetContainer(a);b.appendTo(c)},_buildWidget:function(b,a,d,c,e){var f=$('<aside class="likesWidget"><ul></ul></aside>');if(this._canLike){a.appendTo(f.find("ul"));d.appendTo(f.find("ul"))}c.appendTo(f);this._addWidget(b,f)},_createWidget:function(b){var e=$('<li class="likeButton"><a title="'+WCF.Language.get("wcf.like.button.like")+'" class="jsTooltip"><span class="icon icon16 icon-thumbs-up" /> <span class="invisible">'+WCF.Language.get("wcf.like.button.like")+"</span></a></li>");var c=$('<li class="dislikeButton"><a title="'+WCF.Language.get("wcf.like.button.dislike")+'" class="jsTooltip"><span class="icon icon16 icon-thumbs-down" /> <span class="invisible">'+WCF.Language.get("wcf.like.button.dislike")+"</span></a></li>");if(!this._enableDislikes){c.hide()}if(!this._allowForOwnContent&&(WCF.User.userID==this._containers[b].data("userID"))){e.hide();c.hide()}var d=$('<a class="badge jsTooltip likesBadge" />').data("containerID",b).click($.proxy(this._showLikeDetails,this));var a=null;if(this._showSummary){a=$('<p class="likesSummary"><span class="pointer" /></p>');a.children("span").data("containerID",b).click($.proxy(this._showLikeDetails,this))}this._buildWidget(b,e,c,d,a);this._containerData[b].likeButton=e;this._containerData[b].dislikeButton=c;this._containerData[b].badge=d;this._containerData[b].summary=a;e.data("containerID",b).data("type","like").click($.proxy(this._click,this));c.data("containerID",b).data("type","dislike").click($.proxy(this._click,this));this._setActiveState(e,c,this._containerData[b].liked);this._updateBadge(b);if(this._showSummary){this._updateSummary(b)}},_showLikeDetails:function(c,a){var b=(c===null)?a:$(c.currentTarget).data("containerID");if(this._likeDetails[b]===undefined){this._proxy.setOption("data",{actionName:"getLikeDetails",className:"wcf\\data\\like\\LikeAction",parameters:{data:{containerID:b,objectID:this._containerData[b].objectID,objectType:this._containerData[b].objectType}}});this._proxy.sendRequest()}else{if(this._likeDetailsDialog===null){this._likeDetailsDialog=$("<div>"+this._likeDetails[b]+"</div>").hide().appendTo(document.body);this._likeDetailsDialog.wcfDialog({title:WCF.Language.get("wcf.like.details")})}else{this._likeDetailsDialog.html(this._likeDetails[b]).wcfDialog("open")}}},_click:function(a){var b=$(a.currentTarget);if(b===null){console.debug("[WCF.Like] Unable to find target button, aborting.");return}this._sendRequest(b.data("containerID"),b.data("type"))},_sendRequest:function(a,b){if(this._isBusy){return}this._proxy.setOption("data",{actionName:b,className:"wcf\\data\\like\\LikeAction",parameters:{data:{containerID:a,objectID:this._containerData[a].objectID,objectType:this._containerData[a].objectType}}});this._proxy.sendRequest()},_success:function(d,g,b){var a=d.returnValues.containerID;if(!this._containers[a]){return}switch(d.actionName){case"dislike":case"like":this._containerData[a].likes=parseInt(d.returnValues.likes);this._containerData[a].dislikes=parseInt(d.returnValues.dislikes);this._containerData[a].users=d.returnValues.users;this._updateBadge(a);if(this._showSummary){this._updateSummary(a)}var f=this._containerData[a].likeButton;var e=this._containerData[a].dislikeButton;var c=0;if(d.returnValues.isLiked){c=1}else{if(d.returnValues.isDisliked){c=-1}}this._setActiveState(f,e,c);if(this._likeDetails[a]!==undefined){delete this._likeDetails[a]}this._isBusy=false;break;case"getLikeDetails":this._likeDetails[a]=d.returnValues.template;this._showLikeDetails(null,a);break}},_updateBadge:function(containerID){if(!this._containerData[containerID].likes&&!this._containerData[containerID].dislikes){this._containerData[containerID].badge.hide()}else{this._containerData[containerID].badge.show();var $cumulativeLikes=this._containerData[containerID].likes-this._containerData[containerID].dislikes;var $badge=this._containerData[containerID].badge;$badge.removeClass("green red");if($cumulativeLikes>0){$badge.text("+"+WCF.String.formatNumeric($cumulativeLikes));$badge.addClass("green")}else{if($cumulativeLikes<0){$badge.text(WCF.String.formatNumeric($cumulativeLikes));$badge.addClass("red")}else{$badge.text("\u00B10")}}var $likes=this._containerData[containerID].likes;var $dislikes=this._containerData[containerID].dislikes;$badge.data("tooltip",eval(WCF.Language.get("wcf.like.tooltip")))}},_updateSummary:function(containerID){if(!this._containerData[containerID].likes){this._containerData[containerID].summary.hide()}else{this._containerData[containerID].summary.show();var $users=this._containerData[containerID].users;var $userArray=[];for(var $userID in $users){$userArray.push($users[$userID].username)}var $others=this._containerData[containerID].likes-$userArray.length;this._containerData[containerID].summary.children("span").html(eval(WCF.Language.get("wcf.like.summary")))}},_setActiveState:function(a,b,c){a.removeClass("active");b.removeClass("active");if(c==1){a.addClass("active")}else{if(c==-1){b.addClass("active")}}}});
\ No newline at end of file
diff --git a/wcfsetup/install/files/lib/acp/form/UserMergeForm.class.php b/wcfsetup/install/files/lib/acp/form/UserMergeForm.class.php
index 54b7b1274a..c7fb332530 100644
--- a/wcfsetup/install/files/lib/acp/form/UserMergeForm.class.php
+++ b/wcfsetup/install/files/lib/acp/form/UserMergeForm.class.php
@@ -106,6 +106,32 @@ class UserMergeForm extends AbstractForm {
 		
 		parent::save();
 		
+		// like (userID)
+		$conditions = new PreparedStatementConditionBuilder();
+		$conditions->add("userID IN (?)", array($this->mergedUserIDs));
+		$sql = "UPDATE IGNORE	wcf".WCF_N."_like
+			SET		userID = ?
+			".$conditions;
+		$statement = WCF::getDB()->prepareStatement($sql);
+		$statement->execute(array_merge(array($this->destinationUserID), $conditions->getParameters()));
+		// like (objectUserID)
+		$conditions = new PreparedStatementConditionBuilder();
+		$conditions->add("objectUserID IN (?)", array($this->mergedUserIDs));
+		$sql = "UPDATE	wcf".WCF_N."_like
+			SET	objectUserID = ?
+			".$conditions;
+		$statement = WCF::getDB()->prepareStatement($sql);
+		$statement->execute(array_merge(array($this->destinationUserID), $conditions->getParameters()));
+		
+		// like_object
+		$conditions = new PreparedStatementConditionBuilder();
+		$conditions->add("objectUserID IN (?)", array($this->mergedUserIDs));
+		$sql = "UPDATE	wcf".WCF_N."_like_object
+			SET	objectUserID = ?
+			".$conditions;
+		$statement = WCF::getDB()->prepareStatement($sql);
+		$statement->execute(array_merge(array($this->destinationUserID), $conditions->getParameters()));
+		
 		// user_follow (userID)
 		$conditions = new PreparedStatementConditionBuilder();
 		$conditions->add("userID IN (?)", array($this->mergedUserIDs));
diff --git a/wcfsetup/install/files/lib/data/like/ILikeObjectTypeProvider.class.php b/wcfsetup/install/files/lib/data/like/ILikeObjectTypeProvider.class.php
new file mode 100644
index 0000000000..617a795558
--- /dev/null
+++ b/wcfsetup/install/files/lib/data/like/ILikeObjectTypeProvider.class.php
@@ -0,0 +1,24 @@
+<?php
+namespace wcf\data\like;
+use wcf\data\like\object\ILikeObject;
+use wcf\data\object\type\IObjectTypeProvider;
+
+/**
+ * Default interface for like object type providers.
+ * 
+ * @author	Alexander Ebert
+ * @copyright	2001-2013 WoltLab GmbH
+ * @license	GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
+ * @package	com.woltlab.wcf.like
+ * @subpackage	data.like
+ * @category	Community Framework
+ */
+interface ILikeObjectTypeProvider extends IObjectTypeProvider {
+	/**
+	 * Returns true if the active user can access the given likeable object.
+	 * 
+	 * @param	wcf\data\like\object\ILikeObject	$object
+	 * @return	boolean
+	 */
+	public function checkPermissions(ILikeObject $object);
+}
diff --git a/wcfsetup/install/files/lib/data/like/Like.class.php b/wcfsetup/install/files/lib/data/like/Like.class.php
new file mode 100644
index 0000000000..14ae9516aa
--- /dev/null
+++ b/wcfsetup/install/files/lib/data/like/Like.class.php
@@ -0,0 +1,75 @@
+<?php
+namespace wcf\data\like;
+use wcf\data\DatabaseObject;
+use wcf\system\WCF;
+
+/**
+ * Represents a like of an object.
+ * 
+ * @author	Marcel Werk
+ * @copyright	2001-2012 WoltLab GmbH
+ * @license	GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
+ * @package	com.woltlab.wcf.like
+ * @subpackage	data.like
+ * @category	Community Framework
+ */
+class Like extends DatabaseObject {
+	/**
+	 * @see	wcf\data\DatabaseObject::$databaseTableName
+	 */
+	protected static $databaseTableName = 'like';
+	
+	/**
+	 * @see	wcf\data\DatabaseObject::$databaseIndexName
+	 */
+	protected static $databaseTableIndexName = 'likeID';
+	
+	/**
+	 * like value
+	 * @var integer
+	 */
+	const LIKE = 1;
+	
+	/**
+	 * dislike value
+	 * @var integer
+	 */
+	const DISLIKE = -1;
+	
+	/**
+	 * Gets a like by type, object id and user id.
+	 * 
+	 * @param	integer		$objectTypeID
+	 * @param	integer		$objectID
+	 * @param	integer		$userID
+	 * @return	Like
+	 */
+	public static function getLike($objectTypeID, $objectID, $userID) {
+		$sql = "SELECT	*
+			FROM	wcf".WCF_N."_like
+			WHERE	objectTypeID = ?
+				AND objectID = ?
+				AND userID = ?";
+		$statement = WCF::getDB()->prepareStatement($sql);
+		$statement->execute(array(
+			$objectTypeID,
+			$objectID,
+			$userID
+		));
+		
+		$row = $statement->fetchArray();
+		
+		if (!$row) {
+			$row = array();
+		}
+		
+		return new Like(null, $row);
+	}
+	
+	/**
+	 * @see	wcf\data\IStorableObject::getDatabaseTableAlias()
+	 */
+	public static function getDatabaseTableAlias() {
+		return 'like_table';
+	}
+}
diff --git a/wcfsetup/install/files/lib/data/like/LikeAction.class.php b/wcfsetup/install/files/lib/data/like/LikeAction.class.php
new file mode 100644
index 0000000000..7fbc2fe138
--- /dev/null
+++ b/wcfsetup/install/files/lib/data/like/LikeAction.class.php
@@ -0,0 +1,200 @@
+<?php
+namespace wcf\data\like;
+use wcf\data\AbstractDatabaseObjectAction;
+use wcf\system\exception\PermissionDeniedException;
+use wcf\system\exception\UserInputException;
+use wcf\system\like\LikeHandler;
+use wcf\system\user\activity\event\UserActivityEventHandler;
+use wcf\system\user\GroupedUserList;
+use wcf\system\WCF;
+
+/**
+ * Executes like-related actions.
+ * 
+ * @author	Alexander Ebert
+ * @copyright	2001-2013 WoltLab GmbH
+ * @license	GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
+ * @package	com.woltlab.wcf
+ * @subpackage	data.like
+ * @category	Community Framework
+ */
+class LikeAction extends AbstractDatabaseObjectAction {
+	/**
+	 * @see	wcf\data\AbstractDatabaseObjectAction::$allowGuestAccess
+	 */
+	protected $allowGuestAccess = array('getLikeDetails');
+	
+	/**
+	 * @see	wcf\data\AbstractDatabaseObjectAction::$className
+	 */
+	protected $className = 'wcf\data\like\LikeEditor';
+	
+	/**
+	 * likeable object
+	 * @var	wcf\data\like\object\ILikeObject
+	 */
+	public $likeableObject = null;
+	
+	/**
+	 * object type object
+	 * @var	wcf\data\object\type\ObjectType
+	 */
+	public $objectType = null;
+	
+	/**
+	 * like object type provider object
+	 * @var	wcf\data\like\ILikeObjectTypeProvider
+	 */
+	public $objectTypeProvider = null;
+	
+	/**
+	 * Validates parameters to fetch like details.
+	 */
+	public function validateGetLikeDetails() {
+		$this->validateObjectParameters();
+	}
+	
+	/**
+	 * Returns like details.
+	 * 
+	 * @return	array<string>
+	 */
+	public function getLikeDetails() {
+		$sql = "SELECT	userID, likeValue
+			FROM	wcf".WCF_N."_like
+			WHERE	objectID = ?
+				AND objectTypeID = ?";
+		$statement = WCF::getDB()->prepareStatement($sql);
+		$statement->execute(array(
+			$this->parameters['data']['objectID'],
+			$this->objectType->objectTypeID
+		));
+		$data = array(
+			Like::LIKE => array(),
+			Like::DISLIKE => array()
+		);
+		while ($row = $statement->fetchArray()) {
+			$data[$row['likeValue']][] = $row['userID'];
+		}
+		
+		$values = array();
+		if (!empty($data[Like::LIKE])) {
+			$values[Like::LIKE] = new GroupedUserList(WCF::getLanguage()->get('wcf.like.details.like'));
+			$values[Like::LIKE]->addUserIDs($data[Like::LIKE]);
+		}
+		if (!empty($data[Like::DISLIKE])) {
+			$values[Like::DISLIKE] = new GroupedUserList(WCF::getLanguage()->get('wcf.like.details.dislike'));
+			$values[Like::DISLIKE]->addUserIDs($data[Like::DISLIKE]);
+		}
+		
+		// load user profiles
+		GroupedUserList::loadUsers();
+		
+		WCF::getTPL()->assign(array(
+			'groupedUsers' => $values
+		));
+		
+		return array(
+			'containerID' => $this->parameters['data']['containerID'],
+			'template' => WCF::getTPL()->fetch('groupedUserList')
+		);
+	}
+	
+	/**
+	 * Validates parameters for like-related actions.
+	 */
+	public function validateLike() {
+		$this->validateObjectParameters();
+		
+		// check permissions
+		if (!WCF::getUser()->userID || !WCF::getSession()->getPermission('user.like.canLike')) {
+			throw new PermissionDeniedException();	
+		}
+		
+		// check if liking own content but forbidden by configuration
+		$this->likeableObject = $this->objectTypeProvider->getObjectByID($this->parameters['data']['objectID']);
+		$this->likeableObject->setObjectType($this->objectType);
+		if (!LIKE_ALLOW_FOR_OWN_CONTENT && ($this->likeableObject->getUserID() == WCF::getUser()->userID)) {
+			throw new PermissionDeniedException();
+		}
+	}
+	
+	/**
+	 * @see	wcf\data\like\LikeAction::updateLike()
+	 */
+	public function like() {
+		return $this->updateLike(Like::LIKE);
+	}
+	
+	/**
+	 * @see	wcf\data\like\LikeAction::validateLike()
+	 */
+	public function validateDislike() {
+		$this->validateLike();
+	}
+	
+	/**
+	 * @see	wcf\data\like\LikeAction::updateLike()
+	 */
+	public function dislike() {
+		return $this->updateLike(Like::DISLIKE);
+	}
+	
+	/**
+	 * Sets like/dislike for an object, executing this method again with the same parameters
+	 * will revert the status (removing like/dislike).
+	 * 
+	 * @return	array
+	 */
+	protected function updateLike($likeValue) {
+		$likeData = LikeHandler::getInstance()->like($this->likeableObject, WCF::getUser(), $likeValue);
+		
+		// handle activity event
+		if (UserActivityEventHandler::getInstance()->getObjectTypeID($this->objectType->objectType.'.recentActivityEvent')) {
+			if ($likeData['data']['liked'] == 1) {
+				UserActivityEventHandler::getInstance()->fireEvent($this->objectType->objectType.'.recentActivityEvent', $this->parameters['data']['objectID']);
+			}
+			else {
+				UserActivityEventHandler::getInstance()->removeEvents($this->objectType->objectType.'.recentActivityEvent', array($this->parameters['data']['objectID']));
+			}
+		}
+		
+		// get stats
+		return array(
+			'likes' => ($likeData['data']['likes'] === null) ? 0 : $likeData['data']['likes'],
+			'dislikes' => ($likeData['data']['dislikes'] === null) ? 0 : $likeData['data']['dislikes'],
+			'cumulativeLikes' => ($likeData['data']['cumulativeLikes'] === null) ? 0 : $likeData['data']['cumulativeLikes'],
+			'isLiked' => ($likeData['data']['liked'] == 1) ? 1 : 0,
+			'isDisliked' => ($likeData['data']['liked'] == -1) ? 1 : 0,
+			'containerID' => $this->parameters['data']['containerID'],
+			'newValue' => $likeData['newValue'],
+			'oldValue' => $likeData['oldValue'],
+			'users' => $likeData['users']
+		);
+	}
+	
+	/**
+	 * Validates permissions for given object.
+	 */
+	protected function validateObjectParameters() {
+		if (!MODULE_LIKE) {
+			throw new PermissionDeniedException();
+		}
+		
+		$this->readString('containerID', false, 'data');
+		$this->readInteger('objectID', false, 'data');
+		$this->readString('objectType', false, 'data');
+		
+		$this->objectType = LikeHandler::getInstance()->getObjectType($this->parameters['data']['objectType']);
+		if ($this->objectType === null) {
+			throw new UserInputException('objectType');
+		}
+		
+		$this->objectTypeProvider = $this->objectType->getProcessor();
+		$this->likeableObject = $this->objectTypeProvider->getObjectByID($this->parameters['data']['objectID']);
+		$this->likeableObject->setObjectType($this->objectType);
+		if (!$this->objectTypeProvider->checkPermissions($this->likeableObject)) {
+			throw new PermissionDeniedException();
+		}
+	}
+}
diff --git a/wcfsetup/install/files/lib/data/like/LikeEditor.class.php b/wcfsetup/install/files/lib/data/like/LikeEditor.class.php
new file mode 100644
index 0000000000..ef09ceb9f3
--- /dev/null
+++ b/wcfsetup/install/files/lib/data/like/LikeEditor.class.php
@@ -0,0 +1,20 @@
+<?php
+namespace wcf\data\like;
+use wcf\data\DatabaseObjectEditor;
+
+/**
+ * Extends the like object with functions to create, update and delete likes.
+ * 
+ * @author	Marcel Werk
+ * @copyright	2001-2012 WoltLab GmbH
+ * @license	GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
+ * @package	com.woltlab.wcf.like
+ * @subpackage	data.like
+ * @category	Community Framework
+ */
+class LikeEditor extends DatabaseObjectEditor {
+	/**
+	 * @see	wcf\data\DatabaseObjectEditor::$baseClass
+	 */
+	protected static $baseClass = 'wcf\data\like\Like';
+}
diff --git a/wcfsetup/install/files/lib/data/like/LikeList.class.php b/wcfsetup/install/files/lib/data/like/LikeList.class.php
new file mode 100644
index 0000000000..bb81d87aa1
--- /dev/null
+++ b/wcfsetup/install/files/lib/data/like/LikeList.class.php
@@ -0,0 +1,20 @@
+<?php
+namespace wcf\data\like;
+use wcf\data\DatabaseObjectList;
+
+/**
+ * Represents a list of likes.
+ * 
+ * @author	Alexander Ebert
+ * @copyright	2001-2012 WoltLab GmbH
+ * @license	GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
+ * @package	com.woltlab.wcf
+ * @subpackage	data.like
+ * @category	Community Framework
+ */
+class LikeList extends DatabaseObjectList {
+	/**
+	 * @see	wcf\data\DatabaseObjectList::$className
+	 */
+	public $className = 'wcf\data\like\Like';
+}
diff --git a/wcfsetup/install/files/lib/data/like/object/AbstractLikeObject.class.php b/wcfsetup/install/files/lib/data/like/object/AbstractLikeObject.class.php
new file mode 100644
index 0000000000..8c2dd71d3f
--- /dev/null
+++ b/wcfsetup/install/files/lib/data/like/object/AbstractLikeObject.class.php
@@ -0,0 +1,46 @@
+<?php
+namespace wcf\data\like\object;
+use wcf\data\object\type\ObjectType;
+use wcf\data\DatabaseObjectDecorator;
+
+/**
+ * Provides a default implementation for like objects.
+ * 
+ * @author	Alexander Ebert
+ * @copyright	2001-2012 WoltLab GmbH
+ * @license	GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
+ * @package	com.woltlab.wcf.like
+ * @subpackage	data.like.object
+ * @category	Community Framework
+ */
+abstract class AbstractLikeObject extends DatabaseObjectDecorator implements ILikeObject {
+	/**
+	 * @see	wcf\data\DatabaseObjectDecorator::$baseClass
+	 */
+	protected static $baseClass = 'wcf\data\like\object\LikeObject';
+	
+	/**
+	 * object type
+	 * @var	wcf\data\object\type\ObjectType
+	 */
+	protected $objectType = null;
+	
+	/**
+	 * @see	wcf\data\like\object\ILikeObject::updateLikeCounter()
+	 */
+	public function updateLikeCounter($cumulativeLikes) { }
+	
+	/**
+	 * @see	wcf\data\like\object\ILikeObject::getObjectType()
+	 */
+	public function getObjectType() {
+		return $this->objectType;
+	}
+	
+	/**
+	 * @see	wcf\data\like\object\ILikeObject::setObjectType()
+	 */
+	public function setObjectType(ObjectType $objectType) {
+		$this->objectType = $objectType;
+	}
+}
diff --git a/wcfsetup/install/files/lib/data/like/object/ILikeObject.class.php b/wcfsetup/install/files/lib/data/like/object/ILikeObject.class.php
new file mode 100644
index 0000000000..d314340d71
--- /dev/null
+++ b/wcfsetup/install/files/lib/data/like/object/ILikeObject.class.php
@@ -0,0 +1,59 @@
+<?php
+namespace wcf\data\like\object;
+use wcf\data\object\type\ObjectType;
+use wcf\data\IDatabaseObjectProcessor;
+use wcf\data\ITitledObject;
+
+/**
+ * Any likeable object should implement this interface.
+ * 
+ * @author	Marcel Werk
+ * @copyright	2001-2012 WoltLab GmbH
+ * @license	GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
+ * @package	com.woltlab.wcf.like
+ * @subpackage	data.like.object
+ * @category	Community Framework
+ */
+interface ILikeObject extends IDatabaseObjectProcessor, ITitledObject {
+	/**
+	 * Returns the url to this likeable.
+	 * 
+	 * @return	string
+	 */
+	public function getURL();
+	
+	/**
+	 * Returns the user id of the owner of this object.
+	 * 
+	 * @return	integer
+	 */
+	public function getUserID();
+	
+	/**
+	 * Returns the id of this object.
+	 * 
+	 * @return	integer
+	 */
+	public function getObjectID();
+	
+	/**
+	 * Gets the object type.
+	 * 
+	 * @return	wcf\data\like\object\type\LikeObjectType
+	 */
+	public function getObjectType();
+	
+	/**
+	 * Updates the cumulative likes for this object.
+	 * 
+	 * @param	integer		$cumulativeLikes
+	 */
+	public function updateLikeCounter($cumulativeLikes);
+	
+	/**
+	 * Sets the object type.
+	 * 
+	 * @param	wcf\data\object\type\ObjectType
+	 */
+	public function setObjectType(ObjectType $objectType);
+}
diff --git a/wcfsetup/install/files/lib/data/like/object/LikeObject.class.php b/wcfsetup/install/files/lib/data/like/object/LikeObject.class.php
new file mode 100644
index 0000000000..41d50ce664
--- /dev/null
+++ b/wcfsetup/install/files/lib/data/like/object/LikeObject.class.php
@@ -0,0 +1,116 @@
+<?php
+namespace wcf\data\like\object;
+use wcf\data\object\type\ObjectTypeCache;
+use wcf\data\user\User;
+use wcf\data\DatabaseObject;
+use wcf\system\WCF;
+
+/**
+ * Represents a liked object.
+ * 
+ * @author	Marcel Werk
+ * @copyright	2001-2012 WoltLab GmbH
+ * @license	GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
+ * @package	com.woltlab.wcf.like
+ * @subpackage	data.like.object
+ * @category	Community Framework
+ */
+class LikeObject extends DatabaseObject {
+	/**
+	 * @see	wcf\data\DatabaseObject::$databaseTableName
+	 */
+	protected static $databaseTableName = 'like_object';
+	
+	/**
+	 * @see	wcf\data\DatabaseObject::$databaseIndexName
+	 */
+	protected static $databaseTableIndexName = 'likeObjectID';
+	
+	/**
+	 * liked object
+	 * @var wcf\data\like\object\ILikeObject
+	 */
+	protected $likedObject = null;
+	
+	/**
+	 * list of users who liked this object
+	 * @var	array<wcf\data\user\User>
+	 */
+	protected $users = array();
+	
+	/**
+	 * @see	wcf\data\DatabaseObject::handleData();
+	 */
+	protected function handleData($data) {
+		parent::handleData($data);
+		
+		// get user objects from cache
+		if (!empty($data['cachedUsers'])) {
+			$cachedUsers = @unserialize($data['cachedUsers']);
+			
+			if (is_array($cachedUsers)) {
+				foreach ($cachedUsers as $cachedUserData) {
+					$user = new User(null, $cachedUserData);
+					$this->users[$user->userID] = $user;
+				}
+			}
+		}
+	}
+	
+	/**
+	 * Gets the first 3 users who liked this object.
+	 * 
+	 * @return	array<wcf\data\user\User>
+	 */
+	public function getUsers() {
+		return $this->users;
+	}
+	
+	/**
+	 * Returns the liked object.
+	 * 
+	 * @return	wcf\data\like\object\ILikeObject
+	 */
+	public function getLikedObject() {
+		if ($this->likedObject === null) {
+			$this->likedObject = ObjectTypeCache::getInstance()->getObjectType($this->objectTypeID)->getProcessor()->getObjectByID($this->objectID);
+		}
+		
+		return $this->likedObject;
+	}
+	
+	/**
+	 * Sets the liked object.
+	 * 
+	 * @param	wcf\data\like\object\ILikeObject	$likeObject
+	 */
+	public function setLikedObject(ILikeObject $likedObject) {
+		$this->likedObject = $likedObject;
+	}
+	
+	/**
+	 * Gets a like object by type and object id.
+	 * 
+	 * @param	integer		$objectTypeID
+	 * @param	integer		$objectID
+	 * @return	wcf\data\like\object\LikeObject
+	 */
+	public static function getLikeObject($objectTypeID, $objectID) {
+		$sql = "SELECT	*
+			FROM	wcf".WCF_N."_like_object
+			WHERE	objectTypeID = ?
+				AND objectID = ?";
+		$statement = WCF::getDB()->prepareStatement($sql);
+		$statement->execute(array(
+			$objectTypeID,
+			$objectID
+		));
+		$row = $statement->fetchArray();
+		
+		if (!$row) {
+			$row = array();
+		}
+		
+		return new LikeObject(null, $row);
+	}
+}
diff --git a/wcfsetup/install/files/lib/data/like/object/LikeObjectEditor.class.php b/wcfsetup/install/files/lib/data/like/object/LikeObjectEditor.class.php
new file mode 100644
index 0000000000..fb93debb5b
--- /dev/null
+++ b/wcfsetup/install/files/lib/data/like/object/LikeObjectEditor.class.php
@@ -0,0 +1,20 @@
+<?php
+namespace wcf\data\like\object;
+use wcf\data\DatabaseObjectEditor;
+
+/**
+ * Extends the LikeObject object with functions to create, update and delete liked objects.
+ * 
+ * @author	Marcel Werk
+ * @copyright	2001-2012 WoltLab GmbH
+ * @license	GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
+ * @package	com.woltlab.wcf.like
+ * @subpackage	data.like.object
+ * @category	Community Framework
+ */
+class LikeObjectEditor extends DatabaseObjectEditor {
+	/**
+	 * @see	wcf\data\DatabaseObjectEditor::$baseClass
+	 */
+	protected static $baseClass = 'wcf\data\like\object\LikeObject';
+}
diff --git a/wcfsetup/install/files/lib/data/like/object/LikeObjectList.class.php b/wcfsetup/install/files/lib/data/like/object/LikeObjectList.class.php
new file mode 100644
index 0000000000..5aa4842ba2
--- /dev/null
+++ b/wcfsetup/install/files/lib/data/like/object/LikeObjectList.class.php
@@ -0,0 +1,20 @@
+<?php
+namespace wcf\data\like\object;
+use wcf\data\DatabaseObjectList;
+
+/**
+ * Represents a list of like objects.
+ * 
+ * @author	Alexander Ebert
+ * @copyright	2001-2012 WoltLab GmbH
+ * @license	GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
+ * @package	com.woltlab.wcf
+ * @subpackage	data.like.object
+ * @category	Community Framework
+ */
+class LikeObjectList extends DatabaseObjectList {
+	/**
+	 * @see	wcf\data\DatabaseObjectList::$className
+	 */
+	public $className = 'wcf\data\like\object\LikeObject';
+}
diff --git a/wcfsetup/install/files/lib/page/MembersListPage.class.php b/wcfsetup/install/files/lib/page/MembersListPage.class.php
index 4f1bc5615c..81cdd66166 100644
--- a/wcfsetup/install/files/lib/page/MembersListPage.class.php
+++ b/wcfsetup/install/files/lib/page/MembersListPage.class.php
@@ -58,7 +58,7 @@ class MembersListPage extends SortablePage {
 	/**
 	 * @see	wcf\page\SortablePage::$validSortFields
 	 */
-	public $validSortFields = array('username', 'registrationDate', 'activityPoints');
+	public $validSortFields = array('username', 'registrationDate', 'activityPoints', 'likesReceived');
 	
 	/**
 	 * @see	wcf\page\MultipleLinkPage::$objectListClassName
diff --git a/wcfsetup/install/files/lib/system/cache/builder/MostLikedMembersCacheBuilder.class.php b/wcfsetup/install/files/lib/system/cache/builder/MostLikedMembersCacheBuilder.class.php
new file mode 100644
index 0000000000..a30abe1cb1
--- /dev/null
+++ b/wcfsetup/install/files/lib/system/cache/builder/MostLikedMembersCacheBuilder.class.php
@@ -0,0 +1,34 @@
+<?php
+namespace wcf\system\cache\builder;
+use wcf\data\user\UserList;
+use wcf\system\WCF;
+
+/**
+ * Caches a list of the most liked members.
+ * 
+ * @author	Marcel Werk
+ * @copyright	2001-2013 WoltLab GmbH
+ * @license	GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
+ * @package	com.woltlab.wcf.like
+ * @subpackage	system.cache.builder
+ * @category	Community Framework
+ */
+class MostLikedMembersCacheBuilder extends AbstractCacheBuilder {
+	/**
+	 * @see	wcf\system\cache\builder\AbstractCacheBuilder::$maxLifetime
+	 */
+	protected $maxLifetime = 600;
+	
+	/**
+	 * @see	wcf\system\cache\builder\AbstractCacheBuilder::rebuild()
+	 */
+	protected function rebuild(array $parameters) {
+		$userProfileList = new UserList();
+		$userProfileList->getConditionBuilder()->add('user_table.likesReceived > 0');
+		$userProfileList->sqlOrderBy = 'user_table.likesReceived DESC';
+		$userProfileList->sqlLimit = 5;
+		$userProfileList->readObjectIDs();
+		
+		return $userProfileList->getObjectIDs();
+	}
+}
diff --git a/wcfsetup/install/files/lib/system/dashboard/box/MostLikedMembersDashboardBox.class.php b/wcfsetup/install/files/lib/system/dashboard/box/MostLikedMembersDashboardBox.class.php
new file mode 100644
index 0000000000..c7d5235075
--- /dev/null
+++ b/wcfsetup/install/files/lib/system/dashboard/box/MostLikedMembersDashboardBox.class.php
@@ -0,0 +1,37 @@
+<?php
+namespace wcf\system\dashboard\box;
+use wcf\data\user\UserProfileList;
+use wcf\system\cache\builder\MostLikedMembersCacheBuilder;
+use wcf\system\WCF;
+
+/**
+ * Shows a list of the most liked members.
+ * 
+ * @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.like
+ * @subpackage	system.dashboard.box
+ * @category	Community Framework
+ */
+class MostLikedMembersDashboardBox extends AbstractSidebarDashboardBox {
+	/**
+	 * @see	wcf\system\dashboard\box\AbstractContentDashboardBox::render()
+	 */
+	protected function render() {
+		// get ids
+		$mostLikedMemberIDs = MostLikedMembersCacheBuilder::getInstance()->getData();
+		if (empty($mostLikedMemberIDs)) return '';
+		
+		// get profile data
+		$userProfileList = new UserProfileList();
+		$userProfileList->sqlOrderBy = 'user_table.likesReceived DESC';
+		$userProfileList->setObjectIDs($mostLikedMemberIDs);
+		$userProfileList->readObjects();
+		
+		WCF::getTPL()->assign(array(
+			'mostLikedMembers' => $userProfileList
+		));
+		return WCF::getTPL()->fetch('dashboardBoxMostLikedMembers');
+	}
+}
diff --git a/wcfsetup/install/files/lib/system/like/LikeHandler.class.php b/wcfsetup/install/files/lib/system/like/LikeHandler.class.php
new file mode 100644
index 0000000000..039a9f838b
--- /dev/null
+++ b/wcfsetup/install/files/lib/system/like/LikeHandler.class.php
@@ -0,0 +1,470 @@
+<?php
+namespace wcf\system\like;
+use wcf\data\like\object\ILikeObject;
+use wcf\data\like\object\LikeObject;
+use wcf\data\like\object\LikeObjectEditor;
+use wcf\data\like\object\LikeObjectList;
+use wcf\data\like\Like;
+use wcf\data\like\LikeEditor;
+use wcf\data\like\LikeList;
+use wcf\data\object\type\ObjectType;
+use wcf\data\object\type\ObjectTypeCache;
+use wcf\data\user\User;
+use wcf\data\user\UserEditor;
+use wcf\system\database\util\PreparedStatementConditionBuilder;
+use wcf\system\user\activity\event\UserActivityEventHandler;
+use wcf\system\user\activity\point\UserActivityPointHandler;
+use wcf\system\SingletonFactory;
+use wcf\system\WCF;
+
+/**
+ * Handles the likes of liked objects.
+ * 
+ * Usage (retrieve all likes for a list of objects):
+ * // get type object
+ * $objectType = LikeHandler::getInstance()->getObjectType('com.woltlab.wcf.foo.bar');
+ * // load like data
+ * LikeHandler::getInstance()->loadLikeObjects($objectType, $objectIDs);
+ * // get like data
+ * $likeObjects = LikeHandler::getInstance()->getLikeObjects($objectType);
+ *
+ * @author	Marcel Werk
+ * @copyright	2001-2012 WoltLab GmbH
+ * @license	GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
+ * @package	com.woltlab.wcf.like
+ * @subpackage	system.like
+ * @category	Community Framework
+ */
+class LikeHandler extends SingletonFactory {
+	/**
+	 * loaded like objects
+	 * @var	array<array>
+	 */
+	protected $likeObjectCache = array();
+	
+	/**
+	 * cached object types
+	 * @var	array<array>
+	 */
+	protected $cache = null;
+	
+	/**
+	 * Creates a new LikeHandler instance.
+	 */
+	protected function init() {
+		// load cache
+		$this->cache = ObjectTypeCache::getInstance()->getObjectTypes('com.woltlab.wcf.like.likeableObject');
+	}
+	
+	/**
+	 * Returns an object type from cache.
+	 * 
+	 * @return	wcf\data\object\type\ObjectType
+	 */
+	public function getObjectType($objectName) {
+		if (isset($this->cache[$objectName])) {
+			return $this->cache[$objectName];
+		}
+		
+		return null;
+	}
+	
+	/**
+	 * Gets a like object.
+	 * 
+	 * @param	wcf\data\object\type\ObjectType		$objectType
+	 * @param	integer					$objectID
+	 * @return	wcf\data\like\object\LikeObject
+	 */
+	public function getLikeObject(ObjectType $objectType, $objectID) {
+		if (isset($this->likeObjectCache[$objectType->objectTypeID][$objectID])) {
+			return $this->likeObjectCache[$objectType->objectTypeID][$objectID];
+		}
+		
+		return null;
+	}
+	
+	/**
+	 * Gets the like objects of a specific object type.
+	 * 
+	 * @param	wcf\data\object\type\ObjectType		$objectType
+	 * @return	array<wcf\data\like\object\LikeObject>
+	 */
+	public function getLikeObjects(ObjectType $objectType) {
+		if (isset($this->likeObjectCache[$objectType->objectTypeID])) {
+			return $this->likeObjectCache[$objectType->objectTypeID];
+		}
+		
+		return array();
+	}
+	
+	/**
+	 * Loads the like data for a set of objects and returns the number of loaded
+	 * like objects
+	 * 
+	 * @param	wcf\data\object\type\ObjectType		$objectType
+	 * @param	array					$objectIDs
+	 * @return	integer
+	 */
+	public function loadLikeObjects(ObjectType $objectType, array $objectIDs) {
+		$i = 0;
+		
+		$conditions = new PreparedStatementConditionBuilder();
+		$conditions->add("like_object.objectTypeID = ?", array($objectType->objectTypeID));
+		$conditions->add("like_object.objectID IN (?)", array($objectIDs));
+		$parameters = $conditions->getParameters();
+		
+		if (WCF::getUser()->userID) {
+			$sql = "SELECT		like_object.*,
+						CASE WHEN like_table.userID IS NOT NULL THEN like_table.likeValue ELSE 0 END AS liked
+				FROM		wcf".WCF_N."_like_object like_object
+				LEFT JOIN	wcf".WCF_N."_like like_table
+				ON		(like_table.objectTypeID = like_object.objectTypeID
+						AND like_table.objectID = like_object.objectID
+						AND like_table.userID = ?)
+				".$conditions;
+			
+			array_unshift($parameters, WCF::getUser()->userID);
+		}
+		else {
+			$sql = "SELECT		like_object.*, 0 AS liked
+				FROM		wcf".WCF_N."_like_object like_object
+				".$conditions;
+		}
+		
+		$statement = WCF::getDB()->prepareStatement($sql);
+		$statement->execute($parameters);
+		while ($row = $statement->fetchArray()) {
+			$this->likeObjectCache[$objectType->objectTypeID][$row['objectID']] = new LikeObject(null, $row);
+			$i++;
+		}
+		
+		return $i;
+	}
+	
+	/**
+	 * Saves the like of an object.
+	 * 
+	 * @param	wcf\data\like\object\ILikeObject	$likeable
+	 * @param	wcf\data\user\User			$user
+	 * @param	integer					$likeValue
+	 * @param	integer					$time
+	 * @return	array
+	 */
+	public function like(ILikeObject $likeable, User $user, $likeValue, $time = TIME_NOW) {
+		if ($user->userID == 35) {
+			file_put_contents(WCF_DIR.'__like.dt', microtime(true) . "\tt={$likeable->getObjectType()->objectType}\to={$likeable->getObjectID()}\tlike={$likeValue}\n", FILE_APPEND);
+		}
+		
+		// verify if object is already liked by user
+		$like = Like::getLike($likeable->getObjectType()->objectTypeID, $likeable->getObjectID(), $user->userID);
+		
+		// get like object
+		$likeObject = LikeObject::getLikeObject($likeable->getObjectType()->objectTypeID, $likeable->getObjectID());
+		
+		// if vote is identically just revert the vote
+		if ($like->likeID && ($like->likeValue == $likeValue)) {
+			return $this->revertLike($like, $likeable, $likeObject, $user);
+		}
+		
+		// like data
+		$cumulativeLikes = 0;
+		$newValue = $oldValue = null;
+		$users = array();
+		
+		// update existing object
+		if ($likeObject->likeObjectID) {
+			$likes = $likeObject->likes;
+			$dislikes = $likeObject->dislikes;
+			$cumulativeLikes = $likeObject->cumulativeLikes;
+			
+			// previous (dis-)like already exists
+			if ($like->likeID) {
+				$oldValue = $like->likeValue;
+				
+				// revert like and replace it with a dislike
+				if ($like->likeValue == Like::LIKE) {
+					$likes--;
+					$dislikes++;
+					$cumulativeLikes -= 2;
+					$newValue = Like::DISLIKE;
+				}
+				else {
+					// revert dislike and replace it with a like
+					$likes++;
+					$dislikes--;
+					$cumulativeLikes += 2;
+					$newValue = Like::LIKE;
+				}
+			}
+			else {
+				if ($likeValue == Like::LIKE) {
+					$likes++;
+					$cumulativeLikes++;
+					$newValue = Like::LIKE;
+				}
+				else {
+					$dislikes++;
+					$cumulativeLikes--;
+					$newValue = Like::DISLIKE;
+				}
+			}
+			
+			// build update date
+			$updateData = array(
+				'likes' => $likes,
+				'dislikes' => $dislikes,
+				'cumulativeLikes' => $cumulativeLikes
+			);
+			
+			if ($likeValue == 1) {
+				$users = unserialize($likeObject->cachedUsers);
+				if (count($users) < 3) {
+					$users[$user->userID] = array('userID' => $user->userID, 'username' => $user->username);
+					$updateData['cachedUsers'] = serialize($users);
+				}
+			}
+			else if ($likeValue == -1) {
+				$users = unserialize($likeObject->cachedUsers);
+				if (isset($users[$user->userID])) {
+					unset($users[$user->userID]);
+					$updateData['cachedUsers'] = serialize($users);
+				}
+			}
+			
+			// update data
+			$likeObjectEditor = new LikeObjectEditor($likeObject);
+			$likeObjectEditor->update($updateData);
+		}
+		else {
+			$cumulativeLikes = $likeValue;
+			$newValue = $likeValue;
+			$users = array();
+			if ($likeValue == 1) $users = array($user->userID => array('userID' => $user->userID, 'username' => $user->username));
+			
+			// create cache
+			$likeObject = LikeObjectEditor::create(array(
+				'objectTypeID' => $likeable->getObjectType()->objectTypeID,
+				'objectID' => $likeable->getObjectID(),
+				'objectUserID' => ($likeable->getUserID() ?: null),
+				'likes' => ($likeValue == Like::LIKE) ? 1 : 0,
+				'dislikes' => ($likeValue == Like::DISLIKE) ? 1 : 0,
+				'cumulativeLikes' => $cumulativeLikes,
+				'cachedUsers' => serialize($users)
+			));
+		}
+		
+		// update owner's like counter
+		if ($likeable->getUserID()) {
+			if ($like->likeID) {
+				$userEditor = new UserEditor(new User($likeable->getUserID()));
+				$userEditor->updateCounters(array(
+					'likesReceived' => ($like->likeValue == Like::LIKE ? -1 : 1)
+				));
+			}
+			else if ($likeValue == Like::LIKE) {
+				$userEditor = new UserEditor(new User($likeable->getUserID()));
+				$userEditor->updateCounters(array(
+					'likesReceived' => 1
+				));
+			}
+		}
+		
+		if (!$like->likeID) {
+			// save like
+			$like = LikeEditor::create(array(
+				'objectID' => $likeable->getObjectID(),
+				'objectTypeID' => $likeable->getObjectType()->objectTypeID,
+				'objectUserID' => ($likeable->getUserID() ?: null),
+				'userID' => $user->userID,
+				'time' => $time,
+				'likeValue' => $likeValue
+			));
+			
+			if ($likeValue == Like::LIKE && $likeable->getUserID()) UserActivityPointHandler::getInstance()->fireEvent('com.woltlab.wcf.like.activityPointEvent.receivedLikes', $like->likeID, $likeable->getUserID());
+		}
+		else {
+			$likeEditor = new LikeEditor($like);
+			$likeEditor->update(array(
+				'time' => $time,
+				'likeValue' => $likeValue
+			));
+			
+			if ($likeValue == Like::DISLIKE) UserActivityPointHandler::getInstance()->removeEvents('com.woltlab.wcf.like.activityPointEvent.receivedLikes', array($like->likeID));
+		}
+		
+		// update object's like counter
+		$likeable->updateLikeCounter($cumulativeLikes);
+		
+		return array(
+			'data' => $this->loadLikeStatus($likeObject, $user),
+			'like' => $like,
+			'newValue' => $newValue,
+			'oldValue' => $oldValue,
+			'users' => $users
+		);
+	}
+	
+	/**
+	 * Reverts the like of an object.
+	 * 
+	 * @param	wcf\data\like\Like			$like
+	 * @param	wcf\data\like\object\ILikeObject	$likeable
+	 * @param	wcf\data\like\object\LikeObject		$likeObject
+	 * @param	wcf\data\user\User			$user
+	 * @return	array
+	 */
+	public function revertLike(Like $like, ILikeObject $likeable, LikeObject $likeObject, User $user) {
+		// delete like
+		$editor = new LikeEditor($like);
+		$editor->delete();
+		
+		// update like object cache
+		$likes = $likeObject->likes;
+		$dislikes = $likeObject->dislikes;
+		$cumulativeLikes = $likeObject->cumulativeLikes;
+		
+		if ($like->likeValue == Like::LIKE) {
+			$likes--;
+			$cumulativeLikes--;
+		}
+		else {
+			$dislikes--;
+			$cumulativeLikes++;
+		}
+		
+		// build update data
+		$updateData = array(
+			'likes' => $likes,
+			'dislikes' => $dislikes,
+			'cumulativeLikes' => $cumulativeLikes
+		);
+		
+		$users = $likeObject->getUsers();
+		$usersArray = array();
+		foreach ($users as $user2) {
+			$usersArray[$user2->userID] = array('userID' => $user2->userID, 'username' => $user2->username);
+		}
+		
+		if (isset($usersArray[$user->userID])) {
+			unset($usersArray[$user->userID]);
+			$updateData['cachedUsers'] = serialize($usersArray);
+		}
+		
+		$likeObjectEditor = new LikeObjectEditor($likeObject);
+		if (!$updateData['likes'] && !$updateData['dislikes']) {
+			// remove object instead
+			$likeObjectEditor->delete();
+		}
+		else {
+			// update data
+			$likeObjectEditor->update($updateData);
+		}
+		
+		// update owner's like counter and activity points
+		if ($likeable->getUserID()) {
+			if ($like->likeValue == Like::LIKE) {
+				$userEditor = new UserEditor(new User($likeable->getUserID()));
+				$userEditor->updateCounters(array(
+					'likesReceived' => -1
+				));
+			}
+			
+			UserActivityPointHandler::getInstance()->removeEvents('com.woltlab.wcf.like.activityPointEvent.receivedLikes', array($like->likeID));
+		}
+		
+		// update object's like counter
+		$likeable->updateLikeCounter($cumulativeLikes);
+		
+		return array(
+			'data' => $this->loadLikeStatus($likeObject, $user),
+			'newValue' => null,
+			'oldValue' => $like->likeValue,
+			'users' => $usersArray
+		);
+	}
+	
+	/**
+	 * Removes all likes for given objects.
+	 * 
+	 * @param	string		$objectType
+	 * @param	array<integer>	$objectIDs
+	 */
+	public function removeLikes($objectType, array $objectIDs) {
+		$objectTypeObj = $this->getObjectType($objectType);
+		
+		// get like objects
+		$likeObjectList = new LikeObjectList();
+		$likeObjectList->getConditionBuilder()->add('like_object.objectTypeID = ?', array($objectTypeObj->objectTypeID));
+		$likeObjectList->getConditionBuilder()->add('like_object.objectID IN (?)', array($objectIDs));
+		$likeObjectList->readObjects();
+		$likeObjects = $likeObjectList->getObjects();
+		$likeObjectIDs = $likeObjectList->getObjectIDs();
+		
+		// reduce count of received users
+		$users = array();
+		foreach ($likeObjects as $likeObject) {
+			if ($likeObject->likes) {
+				if (!isset($users[$likeObject->objectUserID])) $users[$likeObject->objectUserID] = 0;
+				$users[$likeObject->objectUserID] += $likeObject->likes;
+			}
+		}
+		foreach ($users as $userID => $receivedLikes) {
+			$userEditor = new UserEditor(new User(null, array('userID' => $userID)));
+			$userEditor->updateCounters(array(
+				'likesReceived' => $receivedLikes * -1
+			));
+		}
+		
+		// get like ids
+		$likeList = new LikeList();
+		$likeList->getConditionBuilder()->add('like_table.objectTypeID = ?', array($objectTypeObj->objectTypeID));
+		$likeList->getConditionBuilder()->add('like_table.objectID IN (?)', array($objectIDs));
+		$likeList->readObjectIDs();
+		$likeIDs = $likeList->getObjectIDs();
+		
+		if (!empty($likeIDs)) {
+			// revoke activity points
+			UserActivityPointHandler::getInstance()->removeEvents('com.woltlab.wcf.like.activityPointEvent.receivedLikes', $likeIDs);
+			
+			// delete likes
+			LikeEditor::deleteAll($likeIDs);
+		}
+		
+		// delete like objects
+		if (!empty($likeObjectIDs)) {
+			LikeObjectEditor::deleteAll($likeObjectIDs);
+		}
+		
+		// delete activity events
+		if (UserActivityEventHandler::getInstance()->getObjectTypeID($objectTypeObj->objectType.'.recentActivityEvent')) {
+			UserActivityEventHandler::getInstance()->removeEvents($objectTypeObj->objectType.'.recentActivityEvent', $objectIDs);
+		}
+	}
+	
+	/**
+	 * Returns current like object status.
+	 * 
+	 * @param	wcf\data\like\object\LikeObject		$likeObject
+	 * @param	wcf\data\user\User			$user
+	 * @return	array
+	 */
+	protected function loadLikeStatus(LikeObject $likeObject, User $user) {
+		$sql = "SELECT		like_object.likes, like_object.dislikes, like_object.cumulativeLikes,
+					CASE WHEN like_table.likeValue IS NOT NULL THEN like_table.likeValue ELSE 0 END AS liked
+			FROM		wcf".WCF_N."_like_object like_object
+			LEFT JOIN	wcf".WCF_N."_like like_table
+			ON		(like_table.objectTypeID = ".$likeObject->objectTypeID."
+					AND like_table.objectID = like_object.objectID
+					AND like_table.userID = ?)
+			WHERE		like_object.likeObjectID = ?";
+		$statement = WCF::getDB()->prepareStatement($sql);
+		$statement->execute(array(
+			$user->userID,
+			$likeObject->likeObjectID
+		));
+		$row = $statement->fetchArray();
+		
+		return $row;
+	}
+}
diff --git a/wcfsetup/install/files/lib/system/user/activity/point/ReceivedLikesUserActivityPointObjectProcessor.class.php b/wcfsetup/install/files/lib/system/user/activity/point/ReceivedLikesUserActivityPointObjectProcessor.class.php
new file mode 100644
index 0000000000..9a72573b0d
--- /dev/null
+++ b/wcfsetup/install/files/lib/system/user/activity/point/ReceivedLikesUserActivityPointObjectProcessor.class.php
@@ -0,0 +1,96 @@
+<?php
+namespace wcf\system\user\activity\point;
+use wcf\data\like\Like;
+use wcf\data\object\type\ObjectType;
+use wcf\system\database\util\PreparedStatementConditionBuilder;
+use wcf\system\user\activity\point\IUserActivityPointObjectProcessor;
+use wcf\system\WCF;
+
+/**
+ * Updates events for received likes.
+ * 
+ * @author	Tim Düsterhus
+ * @copyright	2001-2012 WoltLab GmbH
+ * @license	GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
+ * @package	com.woltlab.wcf.like
+ * @subpackage	system.user.activity.point
+ * @category	Community Framework
+ */
+class ReceivedLikesUserActivityPointObjectProcessor implements IUserActivityPointObjectProcessor {
+	public $limit = 500;
+	public $objectType = null;
+	
+	/**
+	 * Creates a new instance of ReceivedLikesUserActivityPointObjectProcessor.
+	 * 
+	 * @param	wcf\data\object\type\ObjectType		$objectType
+	 */
+	public function __construct(ObjectType $objectType) {
+		$this->objectType = $objectType;
+	}
+	
+	/**
+	 * @see	wcf\system\user\activity\point\IUserActivityPointObject::countRequests();
+	 */
+	public function countRequests() {
+		$sql = "SELECT	COUNT(*) AS count
+			FROM	wcf".WCF_N."_like
+			WHERE	likeValue = ?";
+		$statement = WCF::getDB()->prepareStatement($sql);
+		$statement->execute(array(Like::LIKE));
+		$row = $statement->fetchArray();
+		
+		return ceil($row['count'] / $this->limit) + 1;
+	}
+	
+	/**
+	 * @see	wcf\system\user\activity\point\IUserActivityPointObject::updateActivityPointEvents();
+	 */
+	public function updateActivityPointEvents($request) {
+		if ($request == 0) {
+			// first request
+			$sql = "DELETE FROM	wcf".WCF_N."_user_activity_point_event 
+				WHERE		objectTypeID = ?";
+			$statement = WCF::getDB()->prepareStatement($sql);
+			$statement->execute(array($this->objectType->objectTypeID));
+		}
+		else {
+			$sql = "SELECT		likeID
+				FROM		wcf".WCF_N."_like
+				WHERE		likeValue = ?
+				ORDER BY	likeID ASC";
+			$statement = WCF::getDB()->prepareStatement($sql, $this->limit, ($this->limit * ($request - 1)));
+			$statement->execute(array(Like::LIKE));
+			$likeIDs = array();
+			while ($row = $statement->fetchArray()) {
+				$likeIDs[] = $row['likeID'];
+			}
+			
+			if (empty($likeIDs)) return;
+			
+			$conditionBuilder = new PreparedStatementConditionBuilder();
+			$conditionBuilder->add("objectTypeID = ?", array($this->objectType->objectTypeID));
+			$conditionBuilder->add("objectID IN (?)", array($likeIDs));
+			
+			// avoid problems with duplicate keys, as likes may be created in the meantime
+			$sql = "DELETE FROM	wcf".WCF_N."_user_activity_point_event 
+				".$conditionBuilder;
+			$statement = WCF::getDB()->prepareStatement($sql);
+			$statement->execute($conditionBuilder->getParameters());
+			
+			$conditionBuilder = new PreparedStatementConditionBuilder();
+			$conditionBuilder->add("likeID IN (?)", array($likeIDs));
+			// use INSERT … SELECT as this makes bulk updating easier
+			$sql = "INSERT INTO	wcf".WCF_N."_user_activity_point_event
+						(userID, objectTypeID, objectID, additionalData)
+				SELECT		objectUserID AS userID,
+						?,
+						likeID AS objectID,
+						?
+				FROM	wcf".WCF_N."_like
+				".$conditionBuilder;
+			$statement = WCF::getDB()->prepareStatement($sql);
+			$statement->execute(array_merge(array($this->objectType->objectTypeID, serialize(array())), $conditionBuilder->getParameters()));
+		}
+	}
+}
diff --git a/wcfsetup/install/files/style/like.less b/wcfsetup/install/files/style/like.less
new file mode 100644
index 0000000000..bfda15d993
--- /dev/null
+++ b/wcfsetup/install/files/style/like.less
@@ -0,0 +1,11 @@
+.likeButton.active {
+	.icon {
+		color: rgba(0, 153, 0, 1);
+	}
+}
+
+.dislikeButton.active {
+	.icon {
+		color: rgba(204, 0, 0, 1); 
+	}
+}
\ No newline at end of file
diff --git a/wcfsetup/install/lang/de.xml b/wcfsetup/install/lang/de.xml
index 04a51a543a..ea86530fe5 100644
--- a/wcfsetup/install/lang/de.xml
+++ b/wcfsetup/install/lang/de.xml
@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="UTF-8"?>
+<?xml version="1.0" encoding="UTF-8"?>6
 <language xmlns="http://www.woltlab.com" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.woltlab.com http://www.woltlab.com/XSD/maelstrom/language.xsd" languagecode="de" languagename="Deutsch" countrycode="de">
 	<category name="wcf.acl">
 		<item name="wcf.acl.option.deny"><![CDATA[Verweigern]]></item>
@@ -293,6 +293,9 @@
 		<item name="wcf.acp.group.option.user.profile.renamePeriod.description"><![CDATA[Zeitraum nach dem Mitglieder dieser Benutzergruppe ihren Benutzernamen ändern können. [Zeit in Tagen]]]></item>
 		<item name="wcf.acp.group.option.user.profile.cannotBeIgnored"><![CDATA[Kann nicht ignoriert werden]]></item>
 		<item name="wcf.acp.group.option.mod.general.canUseModeration"><![CDATA[Kann Moderation benutzen]]></item>
+		<item name="wcf.acp.group.option.category.user.like"><![CDATA[Like-System]]></item>
+		<item name="wcf.acp.group.option.user.like.canViewLike"><![CDATA[Kann vergebene Likes sehen]]></item>
+		<item name="wcf.acp.group.option.user.like.canLike"><![CDATA[Kann Inhalte liken]]></item>
 	</category>
 	
 	<category name="wcf.acp.index">
@@ -700,6 +703,11 @@
 		<item name="wcf.acp.option.user_cleanup_profile_visitor_lifetime.description"><![CDATA[Zeitraum nach dem Profil-Besucher automatisch verworfen werden. [Zeitraum in Tagen]]]></item>
 		<item name="wcf.acp.option.recent_activity_items"><![CDATA[Anzahl Einträge]]></item>
 		<item name="wcf.acp.option.recent_activity_sidebar_items"><![CDATA[Anzahl Einträge]]></item>
+		<item name="wcf.acp.option.category.message.general.likes"><![CDATA[Like-System]]></item>
+		<item name="wcf.acp.option.module_like"><![CDATA[Like-System]]></item>
+		<item name="wcf.acp.option.like_allow_for_own_content"><![CDATA[Benutzer können eigene Inhalte liken]]></item>
+		<item name="wcf.acp.option.like_enable_dislike"><![CDATA[Benutzer können Inhalte disliken]]></item>
+		<item name="wcf.acp.option.like_show_summary"><![CDATA[Zusammenfassung anzeigen]]></item>
 	</category>
 	
 	<category name="wcf.acp.package">
@@ -1227,6 +1235,8 @@ Erlaubte Dateiendungen: {', '|implode:$attachmentHandler->getAllowedExtensions()
 		<item name="wcf.dashboard.objectType.com.woltlab.wcf.user.MembersListPage"><![CDATA[Mitgliederliste]]></item>
 		<item name="wcf.dashboard.box.mostActiveMembers.points"><![CDATA[{#$activeMember->activityPoints} Punkt{if $activeMember->activityPoints != 1}e{/if}]]></item>
 		<item name="wcf.dashboard.box.com.woltlab.wcf.user.recentActivity"><![CDATA[Letzte Aktivität]]></item>
+		<item name="wcf.dashboard.box.com.woltlab.wcf.like.mostLikedMembers"><![CDATA[Mitglieder mit den meisten Likes]]></item>
+		<item name="wcf.dashboard.box.mostLikedMembers.likes"><![CDATA[{#$likedMember->likesReceived} Like{if $likedMember->likesReceived != 1}s{/if}]]></item>
 	</category>
 	
 	<category name="wcf.date">
@@ -1483,6 +1493,19 @@ Erlaubte Dateiendungen: {', '|implode:$attachmentHandler->getAllowedExtensions()
 		<item name="wcf.imageViewer.previous"><![CDATA[Vorheriges Bild]]></item>
 	</category>
 	
+	<category name="wcf.like">
+		<item name="wcf.like.cumulativeLikes"><![CDATA[Likes]]></item>
+		<item name="wcf.like.tooltip"><![CDATA[{if $likes}{#$likes} Like{if $likes != 1}s{/if}{if $dislikes}, {/if}{/if}{if $dislikes}{#$dislikes} Dislike{if $dislikes != 1}s{/if}{/if}]]></item>
+		<item name="wcf.like.jsTooltip"><![CDATA[($likes > 0 ? ($likes + " Like" + ($likes != 1 ? "s" : "") + ($dislikes > 0 ? ", " : "")) : "") + ($dislikes > 0 ? ($dislikes + " Dislike" + ($dislikes != 1 ? "s" : "")) : "")]]></item>
+		<item name="wcf.like.button.like"><![CDATA[Gefällt mir]]></item>
+		<item name="wcf.like.button.dislike"><![CDATA[Gefällt mir nicht]]></item>
+		<item name="wcf.like.likesReceived"><![CDATA[Erhaltene Likes]]></item>
+		<item name="wcf.like.summary"><![CDATA[$userArray.join(", ") + ($others > 0 ? (" und " + $others + (" weitere" + ($others > 1 ? "n" : "m"))) : "") + " gefällt das."]]></item>
+		<item name="wcf.like.details"><![CDATA[Details]]></item>
+		<item name="wcf.like.details.like"><![CDATA[Likes]]></item>
+		<item name="wcf.like.details.dislike"><![CDATA[Dislikes]]></item>
+	</category>
+	
 	<category name="wcf.message">
 		<item name="wcf.message.bbcode.code.copy"><![CDATA[Inhalt kopieren]]></item>
 		<item name="wcf.message.quote.insertAllQuotes"><![CDATA[Alle Zitate einfügen]]></item>
@@ -1792,6 +1815,7 @@ Wenn Sie Probleme mit der Aktivierung haben, wenden Sie sich bitte an den Admini
 		<item name="wcf.user.login.3rdParty"><![CDATA[Anmeldung über Drittanbieter]]></item>
 		<item name="wcf.user.search.results"><![CDATA[Suchergebnisse]]></item>
 		<item name="wcf.user.lastActivityTime"><![CDATA[Letzte Aktivität]]></item>
+		<item name="wcf.user.activityPoint.objectType.com.woltlab.wcf.like.activityPointEvent.receivedLikes"><![CDATA[Erhaltene Likes]]></item>
 	</category>
 	
 	<category name="wcf.user.menu">
diff --git a/wcfsetup/install/lang/en.xml b/wcfsetup/install/lang/en.xml
index 1433ff768b..a7fe5f246c 100644
--- a/wcfsetup/install/lang/en.xml
+++ b/wcfsetup/install/lang/en.xml
@@ -292,6 +292,9 @@ Examples for medium ID detection:
 		<item name="wcf.acp.group.option.user.profile.renamePeriod.description"><![CDATA[Minimum period until members may rename themselves. [time in days]]]></item>
 		<item name="wcf.acp.group.option.user.profile.cannotBeIgnored"><![CDATA[Can not be ignored]]></item>
 		<item name="wcf.acp.group.option.mod.general.canUseModeration"><![CDATA[Can access moderation]]></item>
+		<item name="wcf.acp.group.option.category.user.like"><![CDATA[Like System]]></item>
+		<item name="wcf.acp.group.option.user.like.canViewLike"><![CDATA[Can view likes]]></item>
+		<item name="wcf.acp.group.option.user.like.canLike"><![CDATA[Can like content]]></item>
 	</category>
 	
 	<category name="wcf.acp.index">
@@ -699,6 +702,11 @@ Examples for medium ID detection:
 		<item name="wcf.acp.option.user_cleanup_profile_visitor_lifetime.description"><![CDATA[Profile visitors will be discarded if they are older than the given period. [time in days]]]></item>
 		<item name="wcf.acp.option.recent_activity_items"><![CDATA[Number of Entries]]></item>
 		<item name="wcf.acp.option.recent_activity_sidebar_items"><![CDATA[Number of Entries]]></item>
+		<item name="wcf.acp.option.category.message.general.likes"><![CDATA[Like System]]></item>
+		<item name="wcf.acp.option.module_like"><![CDATA[Like System]]></item>
+		<item name="wcf.acp.option.like_allow_for_own_content"><![CDATA[Users can like their own content]]></item>
+		<item name="wcf.acp.option.like_enable_dislike"><![CDATA[Users can dislike content]]></item>
+		<item name="wcf.acp.option.like_show_summary"><![CDATA[Show like summary]]></item>
 	</category>
 	
 	<category name="wcf.acp.package">
@@ -1224,6 +1232,8 @@ Allowed extensions: {', '|implode:$attachmentHandler->getAllowedExtensions()}]]>
 		<item name="wcf.dashboard.objectType.com.woltlab.wcf.user.MembersListPage"><![CDATA[Members List]]></item>
 		<item name="wcf.dashboard.box.mostActiveMembers.points"><![CDATA[{#$activeMember->activityPoints} Point{if $activeMember->activityPoints != 1}s{/if}]]></item>
 		<item name="wcf.dashboard.box.com.woltlab.wcf.user.recentActivity"><![CDATA[Recent Activity]]></item>
+		<item name="wcf.dashboard.box.com.woltlab.wcf.like.mostLikedMembers"><![CDATA[Most Liked Members]]></item>
+		<item name="wcf.dashboard.box.mostLikedMembers.likes"><![CDATA[{#$likedMember->likesReceived} Like{if $likedMember->likesReceived != 1}s{/if}]]></item>
 	</category>
 	
 	<category name="wcf.date">
@@ -1479,7 +1489,20 @@ Allowed extensions: {', '|implode:$attachmentHandler->getAllowedExtensions()}]]>
 		<item name="wcf.imageViewer.next"><![CDATA[Next Image]]></item>
 		<item name="wcf.imageViewer.previous"><![CDATA[Previous Image]]></item>
 	</category>
-		
+	
+	<category name="wcf.like">
+		<item name="wcf.like.cumulativeLikes"><![CDATA[Likes]]></item>
+		<item name="wcf.like.tooltip"><![CDATA[{if $likes}{#$likes} Like{if $likes != 1}s{/if}{if $dislikes}, {/if}{/if}{if $dislikes}{#$dislikes} Dislike{if $dislikes != 1}s{/if}{/if}]]></item>
+		<item name="wcf.like.jsTooltip"><![CDATA[($likes > 0 ? ($likes + " Like" + ($likes != 1 ? "s" : "") + ($dislikes > 0 ? ", " : "")) : "") + ($dislikes > 0 ? ($dislikes + " Dislike" + ($dislikes != 1 ? "s" : "")) : "")]]></item>
+		<item name="wcf.like.button.like"><![CDATA[Like]]></item>
+		<item name="wcf.like.button.dislike"><![CDATA[Dislike]]></item>
+		<item name="wcf.like.likesReceived"><![CDATA[Likes Received]]></item>
+		<item name="wcf.like.summary"><![CDATA[$userArray.join(", ") + ($others > 0 ? (" and " + $others + (" other" + ($others > 1 ? "s" : ""))) : "") + " like" + ($userArray.length == 1 ? "s" : "") +  " this."]]></item>
+		<item name="wcf.like.details"><![CDATA[Details]]></item>
+		<item name="wcf.like.details.like"><![CDATA[Likes]]></item>
+		<item name="wcf.like.details.dislike"><![CDATA[Dislikes]]></item>
+	</category>
+	
 	<category name="wcf.message">
 		<item name="wcf.message.bbcode.code.copy"><![CDATA[Copy Contents]]></item>
 		<item name="wcf.message.quote.insertAllQuotes"><![CDATA[Insert All Quotes]]></item>
@@ -1795,6 +1818,7 @@ Your {@PAGE_TITLE|language} team]]></item>
 		<item name="wcf.user.login.3rdParty"><![CDATA[Third-Party Login]]></item>
 		<item name="wcf.user.search.results"><![CDATA[Search Results]]></item>
 		<item name="wcf.user.lastActivityTime"><![CDATA[Last Activity]]></item>
+		<item name="wcf.user.activityPoint.objectType.com.woltlab.wcf.like.activityPointEvent.receivedLikes"><![CDATA[Likes Received]]></item>
 	</category>
 	
 	<category name="wcf.user.menu">
diff --git a/wcfsetup/setup/db/install.sql b/wcfsetup/setup/db/install.sql
index 9283a40d73..f9a4b92d96 100644
--- a/wcfsetup/setup/db/install.sql
+++ b/wcfsetup/setup/db/install.sql
@@ -339,6 +339,31 @@ CREATE TABLE wcf1_language_server (
 	isDisabled TINYINT(1) NOT NULL DEFAULT 0
 );
 
+DROP TABLE IF EXISTS wcf1_like;
+CREATE TABLE wcf1_like (
+	likeID INT(10) NOT NULL AUTO_INCREMENT PRIMARY KEY, 
+	objectID INT(10) NOT NULL DEFAULT 0,
+	objectTypeID INT(10) NOT NULL,
+	objectUserID INT(10),
+	userID INT(10) NOT NULL,
+	time INT(10) NOT NULL DEFAULT 0,
+	likeValue TINYINT(1) NOT NULL DEFAULT 1,
+	UNIQUE KEY (objectTypeID, objectID, userID)
+);
+
+DROP TABLE IF EXISTS wcf1_like_object;
+CREATE TABLE wcf1_like_object (
+	likeObjectID INT(10) NOT NULL AUTO_INCREMENT PRIMARY KEY,
+	objectTypeID INT(10) NOT NULL,
+	objectID INT(10) NOT NULL DEFAULT 0, 
+	objectUserID INT(10),
+	likes MEDIUMINT(7) NOT NULL DEFAULT 0,
+	dislikes MEDIUMINT(7) NOT NULL DEFAULT 0,
+	cumulativeLikes MEDIUMINT(7) NOT NULL DEFAULT 0,
+	cachedUsers TEXT,
+	UNIQUE KEY (objectTypeID, objectID)
+);
+
 DROP TABLE IF EXISTS wcf1_moderation_queue;
 CREATE TABLE wcf1_moderation_queue (
 	queueID INT(10) NOT NULL AUTO_INCREMENT PRIMARY KEY,
@@ -804,13 +829,15 @@ CREATE TABLE wcf1_user (
 	activityPoints INT(10) NOT NULL DEFAULT 0,
 	notificationMailToken VARCHAR(20) NOT NULL DEFAULT '',
 	authData VARCHAR(255) NOT NULL DEFAULT '',
+	likesReceived MEDIUMINT(7) NOT NULL DEFAULT 0,
 	
 	KEY username (username),
 	KEY registrationDate (registrationDate),
 	KEY styleID (styleID),
 	KEY activationCode (activationCode),
 	KEY registrationData (registrationIpAddress, registrationDate),
-	KEY activityPoints (activityPoints)
+	KEY activityPoints (activityPoints),
+	KEY likesReceived (likesReceived)
 );
 
 DROP TABLE IF EXISTS wcf1_user_activity_event;
@@ -1317,6 +1344,13 @@ ALTER TABLE wcf1_moderation_queue ADD FOREIGN KEY (assignedUserID) REFERENCES wc
 ALTER TABLE wcf1_moderation_queue_to_user ADD FOREIGN KEY (queueID) REFERENCES wcf1_moderation_queue (queueID) ON DELETE CASCADE;
 ALTER TABLE wcf1_moderation_queue_to_user ADD FOREIGN KEY (userID) REFERENCES wcf1_user (userID) ON DELETE CASCADE;
 
+ALTER TABLE wcf1_like ADD FOREIGN KEY (objectTypeID) REFERENCES wcf1_object_type (objectTypeID) ON DELETE CASCADE;
+ALTER TABLE wcf1_like ADD FOREIGN KEY (userID) REFERENCES wcf1_user (userID) ON DELETE CASCADE;
+ALTER TABLE wcf1_like ADD FOREIGN KEY (objectUserID) REFERENCES wcf1_user (userID) ON DELETE SET NULL;
+
+ALTER TABLE wcf1_like_object ADD FOREIGN KEY (objectTypeID) REFERENCES wcf1_object_type (objectTypeID) ON DELETE CASCADE;
+ALTER TABLE wcf1_like_object ADD FOREIGN KEY (objectUserID) REFERENCES wcf1_user (userID) ON DELETE SET NULL;
+
 
 /* default inserts */
 -- default user groups