Merge branch 'feature-plugin-articledata' into develop

6 files changed, 322 insertions, 102 deletions

diff --git a/ratatoeskr/backend.php b/ratatoeskr/backend.php
index 19d3891..a1ab570 100644
--- a/ratatoeskr/backend.php
+++ b/ratatoeskr/backend.php
@@ -12,6 +12,7 @@
 require_once(dirname(__FILE__) . "/sys/models.php");
 require_once(dirname(__FILE__) . "/sys/pwhash.php");
 require_once(dirname(__FILE__) . "/sys/textprocessors.php");
+require_once(dirname(__FILE__) . "/sys/plugin_api.php");
 require_once(dirname(__FILE__) . "/languages.php");
 
 $admin_grp = NULL;
@@ -116,6 +117,7 @@ $backend_subactions = url_action_subactions(array(
 			}
 		}
 		load_language();
+		
 		/* If we are here, user is not logged in... */
 		$url_next = array("login");
 	},
@@ -159,7 +161,7 @@ $backend_subactions = url_action_subactions(array(
 	"content" => url_action_subactions(array(
 		"write" => function(&$data, $url_now, &$url_next)
 		{
-			global $ste, $translation, $textprocessors, $ratatoeskr_settings, $languages;
+			global $ste, $translation, $textprocessors, $ratatoeskr_settings, $languages, $articleeditor_plugins;
 			
 			list($article, $editlang) = array_slice($url_next, 0);
 			if(!isset($editlang))
@@ -234,14 +236,21 @@ $backend_subactions = url_action_subactions(array(
 				if(isset($_POST["saveaslang"]))
 					$editlang = $_POST["saveaslang"];
 			}
+			else
+			{
+				/* Call articleeditor plugins */
+				$article = empty($article) ? NULL : Article::by_urlname($article);
+				foreach($articleeditor_plugins as $plugin)
+					call_user_func($plugin["fx"], $article, False);
+			}
 			
 			function fill_article(&$article, $inputs, $editlang)
 			{
 				$article->urlname   = $inputs["urlname"];
 				$article->status    = $inputs["article_status"];
 				$article->timestamp = $inputs["date"];
-				$article->title  [$editlang] = new Translation($inputs["title"],   ""       );
-				$article->text   [$editlang] = new Translation($inputs["content"], $inputs["content_txtproc"]);
+				$article->title[$editlang]   = new Translation($inputs["title"], "");
+				$article->text[$editlang]    = new Translation($inputs["content"], $inputs["content_txtproc"]);
 				$article->excerpt[$editlang] = new Translation($inputs["excerpt"], $inputs["excerpt_txtproc"]);
 				$article->set_tags(maketags($inputs["tags"], $editlang));
 				$article->set_section($inputs["article_section"]);
@@ -256,15 +265,32 @@ $backend_subactions = url_action_subactions(array(
 				{
 					$article = Article::create($inputs["urlname"]);
 					fill_article($article, $inputs, $editlang);
-					try
+					
+					/* Calling articleeditor plugins */
+					$call_after_save = array();
+					foreach($articleeditor_plugins as $plugin)
 					{
-						$article->save();
-						$ste->vars["article_editurl"] = urlencode($article->urlname) . "/" . urlencode($editlang);
-						$ste->vars["success"] = htmlesc($translation["article_save_success"]);
+						$result = call_user_func($plugin["fx"], $article, True);
+						if(is_string($result))
+							$fail_reasons[] = $result;
+						elseif($result !== NULL)
+							$call_after_save[] = $result;
 					}
-					catch(AlreadyExistsError $e)
+					
+					if(empty($fail_reasons))
 					{
-						$fail_reasons[] = $translation["article_name_already_in_use"];
+						try
+						{
+							$article->save();
+							foreach($call_after_save as $cb)
+								call_user_func($cb, $article);
+							$ste->vars["article_editurl"] = urlencode($article->urlname) . "/" . urlencode($editlang);
+							$ste->vars["success"] = htmlesc($translation["article_save_success"]);
+						}
+						catch(AlreadyExistsError $e)
+						{
+							$fail_reasons[] = $translation["article_name_already_in_use"];
+						}
 					}
 				}
 			}
@@ -272,7 +298,8 @@ $backend_subactions = url_action_subactions(array(
 			{
 				try
 				{
-					$article = Article::by_urlname($article);
+					if(!($article instanceof Article))
+						$article = Article::by_urlname($article);
 				}
 				catch(DoesNotExistError $e)
 				{
@@ -282,15 +309,32 @@ $backend_subactions = url_action_subactions(array(
 				if(empty($fail_reasons) and isset($_POST["save_article"]))
 				{
 					fill_article($article, $inputs, $editlang);
-					try
+					
+					/* Calling articleeditor plugins */
+					$call_after_save = array();
+					foreach($articleeditor_plugins as $plugin)
 					{
-						$article->save();
-						$ste->vars["article_editurl"] = urlencode($article->urlname) . "/" . urlencode($editlang);
-						$ste->vars["success"] = htmlesc($translation["article_save_success"]);
+						$result = call_user_func($plugin["fx"], $article, True);
+						if(is_string($result))
+							$fail_reasons[] = $result;
+						elseif($result !== NULL)
+							$call_after_save[] = $result;
 					}
-					catch(AlreadyExistsError $e)
+					
+					if(empty($fail_reasons))
 					{
-						$fail_reasons[] = $translation["article_name_already_in_use"];
+						try
+						{
+							$article->save();
+							foreach($call_after_save as $cb)
+									call_user_func($cb, $article);
+							$ste->vars["article_editurl"] = urlencode($article->urlname) . "/" . urlencode($editlang);
+							$ste->vars["success"] = htmlesc($translation["article_save_success"]);
+						}
+						catch(AlreadyExistsError $e)
+						{
+							$fail_reasons[] = $translation["article_name_already_in_use"];
+						}
 					}
 				}
 				
@@ -366,6 +410,9 @@ $backend_subactions = url_action_subactions(array(
 					$ste->vars[$k_out] = $inputs[$k_in];
 			}
 			
+			/* Displaying article editor plugins */
+			$ste->vars["displayed_plugins"] = array_map(function($x) { return array("label" => $x["label"], "template" => $x["template"]); }, array_filter($articleeditor_plugins, function($x) { return $x["display"]; }));
+			
 			if(!empty($fail_reasons))
 				$ste->vars["failed"] = $fail_reasons;
 			
diff --git a/ratatoeskr/frontend.php b/ratatoeskr/frontend.php
index 883f842..0bc083b 100644
--- a/ratatoeskr/frontend.php
+++ b/ratatoeskr/frontend.php
@@ -25,9 +25,10 @@ require_once(dirname(__FILE__) . "/libs/kses.php");
  * 
  * Returns:
  * 	Array with these fields:
- * 	* id
- * 	* name
- * 	* title
+ * 	* id    - The ID of the section.
+ * 	* name  - The name of the section.
+ * 	* title - The title of the section in the current language
+ * 	* __obj - The <Section> object. Useful for plugins, so they do not need to fetch the object from the database again.
  */
 function section_transform_ste($section, $lang)
 {
@@ -49,9 +50,10 @@ function section_transform_ste($section, $lang)
  * 
  * Returns:
  * 	Array with these fields:
- * 	* id
- * 	* name
- * 	* title
+ * 	* id    - The ID of the tag.
+ * 	* name  - The name of the tag.
+ * 	* title - The title in the current language.
+ * 	* __obj - The <Tag> object. Useful for plugins, so they do not need to fetch the object from the database again.
  */
 function tag_transform_ste($tag, $lang)
 {
@@ -93,6 +95,7 @@ function tag_transform_ste($tag, $lang)
  * 	* tags (array(sub-fields: <tag_transform_ste>))
  * 	* languages (array: language name=>url)
  * 	* comments_allowed
+ * 	* __obj - Useful for plugins, so they do not need to fetch the object from the database again.
  */
 function article_transform_ste($article, $lang)
 {
diff --git a/ratatoeskr/setup/create_tables.php b/ratatoeskr/setup/create_tables.php
index 819970a..97a4cd5 100644
--- a/ratatoeskr/setup/create_tables.php
+++ b/ratatoeskr/setup/create_tables.php
@@ -20,12 +20,12 @@ CREATE TABLE IF NOT EXISTS `PREFIX_articles` (
   `timestamp` bigint(20) NOT NULL,
   `allow_comments` int(11) NOT NULL,
   PRIMARY KEY (`id`)
-) ENGINE=MyISAM  DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
+) DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
 
 CREATE TABLE IF NOT EXISTS `PREFIX_article_tag_relations` (
   `tag` int(11) NOT NULL,
   `article` int(11) NOT NULL
-) ENGINE=MyISAM DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
+) DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
 
 CREATE TABLE IF NOT EXISTS `PREFIX_comments` (
   `id` int(11) NOT NULL AUTO_INCREMENT,
@@ -38,30 +38,30 @@ CREATE TABLE IF NOT EXISTS `PREFIX_comments` (
   `visible` tinyint(4) NOT NULL,
   `read_by_admin` tinyint(4) NOT NULL,
   PRIMARY KEY (`id`)
-) ENGINE=MyISAM  DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
+) DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
 
 CREATE TABLE IF NOT EXISTS `PREFIX_groups` (
   `id` int(11) NOT NULL AUTO_INCREMENT,
   `name` text COLLATE utf8_unicode_ci NOT NULL,
   PRIMARY KEY (`id`)
-) ENGINE=MyISAM  DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
+) DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
 
 CREATE TABLE IF NOT EXISTS `PREFIX_group_members` (
   `user` int(11) NOT NULL,
   `group` int(11) NOT NULL
-) ENGINE=MyISAM DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
+) DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
 
 CREATE TABLE IF NOT EXISTS `PREFIX_images` (
   `id` int(11) NOT NULL AUTO_INCREMENT,
   `name` text COLLATE utf8_unicode_ci NOT NULL,
   `file` text COLLATE utf8_unicode_ci NOT NULL,
   PRIMARY KEY (`id`)
-) ENGINE=MyISAM  DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
+) DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
 
 CREATE TABLE IF NOT EXISTS `PREFIX_multilingual` (
   `id` int(11) NOT NULL AUTO_INCREMENT,
   PRIMARY KEY (`id`)
-) ENGINE=MyISAM  DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
+) DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
 
 CREATE TABLE IF NOT EXISTS `PREFIX_plugins` (
   `id` int(11) NOT NULL AUTO_INCREMENT,
@@ -82,13 +82,13 @@ CREATE TABLE IF NOT EXISTS `PREFIX_plugins` (
   `update` tinyint(4) NOT NULL,
   `api` int(11) NOT NULL,
   PRIMARY KEY (`id`)
-) ENGINE=MyISAM  DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
+) DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
 
 CREATE TABLE IF NOT EXISTS `PREFIX_plugin_kvstorage` (
   `plugin` int(11) NOT NULL,
   `key` text COLLATE utf8_unicode_ci NOT NULL,
   `value` text COLLATE utf8_unicode_ci NOT NULL
-) ENGINE=MyISAM DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
+) DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
 
 CREATE TABLE IF NOT EXISTS `PREFIX_repositories` (
   `id` int(11) NOT NULL AUTO_INCREMENT,
@@ -98,7 +98,7 @@ CREATE TABLE IF NOT EXISTS `PREFIX_repositories` (
   `pkgcache` text COLLATE utf8_unicode_ci NOT NULL,
   `lastrefresh` bigint(20) NOT NULL,
   PRIMARY KEY (`id`)
-) ENGINE=MyISAM  DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
+) DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
 
 CREATE TABLE IF NOT EXISTS `PREFIX_sections` (
   `id` int(11) NOT NULL AUTO_INCREMENT,
@@ -107,38 +107,38 @@ CREATE TABLE IF NOT EXISTS `PREFIX_sections` (
   `template` text COLLATE utf8_unicode_ci NOT NULL,
   `styles` text COLLATE utf8_unicode_ci NOT NULL,
   PRIMARY KEY (`id`)
-) ENGINE=MyISAM  DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
+) DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
 
 CREATE TABLE IF NOT EXISTS `PREFIX_section_style_relations` (
   `section` int(11) NOT NULL,
   `style` int(11) NOT NULL
-) ENGINE=MyISAM DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
+) DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
 
 CREATE TABLE IF NOT EXISTS `PREFIX_settings_kvstorage` (
   `key` text COLLATE utf8_unicode_ci NOT NULL,
   `value` text COLLATE utf8_unicode_ci NOT NULL
-) ENGINE=MyISAM DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
+) DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
 
 CREATE TABLE IF NOT EXISTS `PREFIX_styles` (
   `id` int(11) NOT NULL AUTO_INCREMENT,
   `name` text COLLATE utf8_unicode_ci NOT NULL,
   `code` text COLLATE utf8_unicode_ci NOT NULL,
   PRIMARY KEY (`id`)
-) ENGINE=MyISAM  DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
+) DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
 
 CREATE TABLE IF NOT EXISTS `PREFIX_tags` (
   `id` int(11) NOT NULL AUTO_INCREMENT,
   `name` text COLLATE utf8_unicode_ci NOT NULL,
   `title` int(11) NOT NULL,
   PRIMARY KEY (`id`)
-) ENGINE=MyISAM  DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
+) DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
 
 CREATE TABLE IF NOT EXISTS `PREFIX_translations` (
   `multilingual` int(11) NOT NULL,
   `language` varchar(10) COLLATE utf8_unicode_ci NOT NULL,
   `text` text COLLATE utf8_unicode_ci NOT NULL,
   `texttype` text COLLATE utf8_unicode_ci NOT NULL
-) ENGINE=MyISAM DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
+) DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
 
 CREATE TABLE IF NOT EXISTS `PREFIX_users` (
   `id` int(11) NOT NULL AUTO_INCREMENT,
@@ -148,7 +148,20 @@ CREATE TABLE IF NOT EXISTS `PREFIX_users` (
   `fullname` text COLLATE utf8_unicode_ci NOT NULL,
   `language` varchar(10) COLLATE utf8_unicode_ci NOT NULL,
   PRIMARY KEY (`id`)
-) ENGINE=MyISAM  DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
+) DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
+
+CREATE TABLE IF NOT EXISTS `PREFIX_meta` (
+  `key` text COLLATE utf8_unicode_ci NOT NULL,
+  `value` text COLLATE utf8_unicode_ci NOT NULL
+) DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
+
+
+CREATE TABLE IF NOT EXISTS `PREFIX_article_extradata` (
+  `article` int(11) NOT NULL,
+  `plugin` int(11) NOT NULL,
+  `key` text COLLATE utf8_unicode_ci NOT NULL,
+  `value` text COLLATE utf8_unicode_ci NOT NULL
+) DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
 SQL;
 
 function create_mysql_tables()
@@ -161,6 +174,8 @@ function create_mysql_tables()
 		if(!empty($q))
 			qdb($q);
 	}
+	
+	qdb("INSERT INTO `PREFIX_meta` (`key`, `value`) VALUES ('dbversion', '%s')", base64_encode(serialize(1)));
 }
 
 ?>
diff --git a/ratatoeskr/sys/models.php b/ratatoeskr/sys/models.php
index fe80ce4..3cda168 100644
--- a/ratatoeskr/sys/models.php
+++ b/ratatoeskr/sys/models.php
@@ -89,6 +89,101 @@ abstract class BySQLRowEnabled
 }
 
 /*
+ * Class: KVStorage
+ * An abstract class for a KVStorage.
+ *
+ * See also:
+ * 	<PluginKVStorage>, <ArticleExtradata>
+ */
+abstract class KVStorage implements Countable, ArrayAccess, Iterator
+{
+	private $keybuffer;
+	private $counter;
+	private $prepared_queries;
+	private $silent_mode;
+	
+	final protected function init($sqltable, $common_fields)
+	{
+		$this->silent_mode = False;
+		$this->keybuffer = array();
+		
+		$selector = "WHERE " . (empty($common_fields) ? 1 : implode(" AND ", array_map(function($x) { return qdb_fmt("`{$x[0]}` = {$x[1]}", $x[2]); }, $common_fields)));
+		$this->prepared_queries = array(
+			"get"    => "SELECT `value` FROM `$sqltable` $selector AND `key` = '%s'",
+			"unset"  => "DELETE FROM `$sqltable` $selector AND `key` = '%s'",
+			"update" => "UPDATE `$sqltable` SET `value` = '%s' $selector AND `key` = '%s'",
+			"create" => "INSERT INTO `$sqltable` (`key`, `value` "
+			            . (empty($common_fields) ?: ", " . implode(", ", array_map(function($x) { return "`".$x[0]."`"; }, $common_fields)))
+			            . ") VALUES ('%s', '%s'"
+			            . (empty($common_fields) ?: ", " . implode(", ", array_map(function($x) { return qdb_fmt($x[1], $x[2]); }, $common_fields)))
+			            . ")"
+		);
+				
+		$result = qdb("SELECT `key` FROM `$sqltable` $selector");
+		while($sqlrow = mysql_fetch_assoc($result))
+			$this->keybuffer[] = $sqlrow["key"];
+		
+		$this->counter = 0;
+	}
+	
+	/*
+	 * Functions: Silent mode
+	 * If the silent mode is enabled, the KVStorage behaves even more like a PHP array, i.e. it just returns NULL,
+	 * if a unknown key was requested and does not throw an DoesNotExistError Exception.
+	 * 
+	 * enable_silent_mode  - Enable the silent mode.
+	 * disable_silent_mode - Disable the silent mode (default).
+	 */
+	final public function enable_silent_mode()  { $this->silent_mode = True;  }
+	final public function disable_silent_mode() { $this->silent_mode = False; }
+	
+	/* Countable interface implementation */
+	final public function count() { return count($this->keybuffer); }
+	
+	/* ArrayAccess interface implementation */
+	final public function offsetExists($offset) { return in_array($offset, $this->keybuffer); }
+	final public function offsetGet($offset)
+	{
+		if($this->offsetExists($offset))
+		{
+			$result = qdb($this->prepared_queries["get"], $offset);
+			$sqlrow = mysql_fetch_assoc($result);
+			return unserialize(base64_decode($sqlrow["value"]));
+		}
+		elseif($this->silent_mode)
+			return NULL;
+		else
+			throw new DoesNotExistError();
+	}
+	final public function offsetUnset($offset)
+	{
+		if($this->offsetExists($offset))
+		{
+			unset($this->keybuffer[array_search($offset, $this->keybuffer)]);
+			$this->keybuffer = array_merge($this->keybuffer);
+			qdb($this->prepared_queries["unset"], $offset);
+		}
+	}
+	final public function offsetSet($offset, $value)
+	{
+		if($this->offsetExists($offset))
+			qdb($this->prepared_queries["update"], base64_encode(serialize($value)), $offset);
+		else
+		{
+			qdb($this->prepared_queries["create"], $offset, base64_encode(serialize($value)));
+			$this->keybuffer[] = $offset;
+		}
+	}
+	
+	/* Iterator interface implementation */
+	final public function rewind()  { return $this->counter = 0; }
+	final public function current() { return $this->offsetGet($this->keybuffer[$this->counter]); }
+	final public function key()     { return $this->keybuffer[$this->counter]; }
+	final public function next()    { ++$this->counter; }
+	final public function valid()   { return isset($this->keybuffer[$this->counter]); }
+}
+
+/*
  * Class: User
  * Data model for Users
  */
@@ -771,13 +866,11 @@ $ratatoeskr_settings = Settings::get_instance();
  * A Key-Value-Storage for Plugins
  * Can be accessed like an array.
  * Keys are strings and Values can be everything serialize() can process.
+ *
+ * Extends the abstract <KVStorage> class.
  */
-class PluginKVStorage implements Countable, ArrayAccess, Iterator
+class PluginKVStorage extends KVStorage
 {
-	private $plugin_id;
-	private $keybuffer;
-	private $counter;
-	
 	/*
 	 * Constructor: __construct
 	 * 
@@ -786,60 +879,10 @@ class PluginKVStorage implements Countable, ArrayAccess, Iterator
 	 */
 	public function __construct($plugin_id)
 	{
-		$this->keybuffer = array();
-		$this->plugin_id = $plugin_id;
-		
-		$result = qdb("SELECT `key` FROM `PREFIX_plugin_kvstorage` WHERE `plugin` = %d", $plugin_id);
-		while($sqlrow = mysql_fetch_assoc($result))
-			$this->keybuffer[] = $sqlrow["key"];
-		
-		$this->counter = 0;
-	}
-	
-	/* Countable interface implementation */
-	public function count() { return count($this->keybuffer); }
-	
-	/* ArrayAccess interface implementation */
-	public function offsetExists($offset) { return in_array($offset, $this->keybuffer); }
-	public function offsetGet($offset)
-	{
-		if($this->offsetExists($offset))
-		{
-			$result = qdb("SELECT `value` FROM `PREFIX_plugin_kvstorage` WHERE `key` = '%s' AND `plugin` = %d", $offset, $this->plugin_id);
-			$sqlrow = mysql_fetch_assoc($result);
-			return unserialize(base64_decode($sqlrow["value"]));
-		}
-		else
-			throw new DoesNotExistError();
-	}
-	public function offsetUnset($offset)
-	{
-		if($this->offsetExists($offset))
-		{
-			unset($this->keybuffer[array_search($offset, $this->keybuffer)]);
-			$this->keybuffer = array_merge($this->keybuffer);
-			qdb("DELETE FROM `PREFIX_plugin_kvstorage` WHERE `key` = '%s' AND `plugin` = %d", $offset, $this->plugin_id);
-		}
-	}
-	public function offsetSet($offset, $value)
-	{
-		if($this->offsetExists($offset))
-			qdb("UPDATE `PREFIX_plugin_kvstorage` SET `value` = '%s' WHERE `key` = '%s' AND `plugin` = %d",
-				base64_encode(serialize($value)), $offset, $this->plugin_id);
-		else
-		{
-			qdb("INSERT INTO `PREFIX_plugin_kvstorage` (`plugin`, `key`, `value`) VALUES (%d, '%s', '%s')",
-				$this->plugin_id, $offset, base64_encode(serialize($value)));
-			$this->keybuffer[] = $offset;
-		}
+		$this->init("PREFIX_plugin_kvstorage", array(
+			array("plugin", "%d", $plugin_id)
+		));
 	}
-	
-	/* Iterator interface implementation */
-	function rewind()  { return $this->position = 0; }
-	function current() { return $this->offsetGet($this->keybuffer[$this->position]); }
-	function key()     { return $this->keybuffer[$this->position]; }
-	function next()    { ++$this->position; }
-	function valid()   { return isset($this->keybuffer[$this->position]); }
 }
 
 /*
@@ -1372,6 +1415,7 @@ class Plugin extends BySQLRowEnabled
 	{
 		qdb("DELETE FROM `PREFIX_plugins` WHERE `id` = %d", $this->id);
 		qdb("DELETE FROM `PREFIX_plugin_kvstorage` WHERE `plugin` = %d", $this->id);
+		qdb("DELETE FROM `PREFIX_article_extradata` WHERE `plugin` = %d", $this->id);
 		if(is_dir(SITE_BASE_PATH . "/ratatoeskr/plugin_extradata/private/" . $this->id))
 			delete_directory(SITE_BASE_PATH . "/ratatoeskr/plugin_extradata/private/" . $this->id);
 		if(is_dir(SITE_BASE_PATH . "/ratatoeskr/plugin_extradata/public/" . $this->id))
@@ -2562,6 +2606,21 @@ WHERE " . implode(" AND ", $subqueries) . " $sorting");
 	}
 	
 	/*
+	 * Function: get_extradata
+	 * Get the extradata for this article and the given plugin.
+	 * 
+	 * Parameters:
+	 * 	$plugin_id - The ID of the plugin.
+	 * 
+	 * Returns:
+	 * 	An <ArticleExtradata> object.
+	 */
+	public function get_extradata($plugin_id)
+	{
+		return new ArticleExtradata($this->id, $plugin_id);
+	}
+	
+	/*
 	 * Function: save
 	 */
 	public function save()
@@ -2604,11 +2663,57 @@ WHERE " . implode(" AND ", $subqueries) . " $sorting");
 			$comment->delete();
 		
 		qdb("DELETE FROM `PREFIX_article_tag_relations` WHERE `article` = %d", $this->id);
+		qdb("DELETE FROM `PREFIX_article_extradata` WHERE `article` = %d", $this->id);
 		qdb("DELETE FROM `PREFIX_articles` WHERE `id` = %d", $this->id);
 	}
 }
 
 /*
+ * Class: ArticleExtradata
+ * A Key-Value-Storage assigned to Articles for plugins to store additional data.
+ * Can be accessed like an array.
+ * Keys are strings and Values can be everything serialize() can process.
+ * 
+ * Extends the abstract <KVStorage> class.
+ */
+class ArticleExtradata extends KVStorage
+{
+	/*
+	 * Constructor: __construct
+	 * 
+	 * Parameters:
+	 * 	$article_id - The ID of the Article.
+	 * 	$plugin_id  - The ID of the Plugin.
+	 */
+	public function __construct($article_id, $plugin_id)
+	{
+		$this->init("PREFIX_article_extradata", array(
+			array("article", "%d", $article_id),
+			array("plugin",  "%d", $plugin_id)
+		));
+	}
+}
+
+/*
+ * Function: dbversion
+ * Get the version of the database structure currently used.
+ * 
+ * Returns:
+ * 	The numerical version of the current database structure.
+ */
+function dbversion()
+{
+	/* Is the meta table present? If no, the version is 0. */
+	$result = qdb("SHOW TABLES LIKE 'PREFIX_meta'");
+	if(mysql_num_rows($result) == 0)
+		return 0;
+	
+	$result = qdb("SELECT `value` FROM `PREFIX_meta` WHERE `key` = 'dbversion'");
+	$sqlrow = mysql_fetch_assoc($result);
+	return unserialize(base64_decode($sqlrow["value"]));
+}
+
+/*
  * Function: clean_database
  * Clean up the database
  */
diff --git a/ratatoeskr/sys/plugin_api.php b/ratatoeskr/sys/plugin_api.php
index f6d1c2d..cd3e42b 100644
--- a/ratatoeskr/sys/plugin_api.php
+++ b/ratatoeskr/sys/plugin_api.php
@@ -15,17 +15,18 @@ require_once(dirname(__FILE__) . "/../frontend.php");
 
 /*
  * Constant: APIVERSION
- * The current API version (5).
+ * The current API version (6).
  */
-define("APIVERSION", 5);
+define("APIVERSION", 6);
 
 /*
  * Array: $api_compat
  * Array of API versions, this version is compatible to (including itself).
  */
-$api_compat = array(3, 4, 5);
+$api_compat = array(3, 4, 5, 6);
+
+$url_handlers = array(); /* master URL handler */
 
-$url_handlers = array();
 /*
  * Function: register_url_handler
  * Register an URL handler. See <ratatoeskr/sys/urlprocess.php> for more details.
@@ -42,6 +43,8 @@ function register_url_handler($name, $callback)
 
 $pluginpages_handlers = array();
 
+$articleeditor_plugins = array();
+
 /*
  * Class: RatatoeskrPlugin
  * An abstract class to be extended in order to write your own Plugin.
@@ -93,7 +96,7 @@ abstract class RatatoeskrPlugin
 	final protected function get_custompub_dir()  { return SITE_BASE_PATH . "/ratatoeskr/plugin_extradata/public/" . $this->id;               }
 	final protected function get_custompub_url()  { return $GLOBALS["rel_path_to_root"] . "/ratatoeskr/plugin_extradata/public/" . $this->id; }
 	final protected function get_template_dir()   { return "/plugintemplates/" . $this->id;                                                   }
-	
+		
 	/*
 	 * Function: register_url_handler
 	 * Register a URL handler
@@ -194,6 +197,33 @@ abstract class RatatoeskrPlugin
 	}
 	
 	/*
+	 * Function: register_articleeditor_plugin
+	 * Register a plugin for the article editor in the backend.
+	 * 
+	 * Parameters:
+	 * 	$label    - The label for the plugin.
+	 * 	$fx       - A function that will be called during the articleeditor.
+	 * 	            This function must accept these parameters:
+	 * 	            * $article       - An <Article> object or NULL, if no Article is edited right now.
+	 * 	            * $about_to_save - If True, the article is about to be saved.
+	 * 	                               If you want to veto the saving, return the rejection reason as a string.
+	 * 	                               If everything is okay and you need to save additional data, return a callback function that accepts the saved <Article> object (that callback should also write data back to the template, if necessary).
+	 * 	                               If everything is okay and you do not need to save additional data, return NULL.
+	 * 	$template - The name of the template to display in the editor, relative to your template directory. If you do not want to display anything, you can set ths to NULL.
+	 */
+	final protected function register_articleeditor_plugin($label, $fx, $template)
+	{
+		global $articleeditor_plugins;
+		
+		$articleeditor_plugins[] = array(
+			"label"    => $label,
+			"fx"       => $fx,
+			"template" => $this->get_template_dir() . "/" . $template,
+			"display"  => $template != NULL
+		);
+	}
+	
+	/*
 	 * Function: get_backend_pluginpage_url
 	 * Get the URL to your backend plugin page.
 	 * 
@@ -207,6 +237,21 @@ abstract class RatatoeskrPlugin
 	}
 	
 	/*
+	 * Function: get_article_extradata
+	 * Get the <ArticleExtradata> object for this plugin and the given article.
+	 * 
+	 * Parameters:
+	 * 	$article - An <Article> object.
+	 * 
+	 * Returns:
+	 * 	An <ArticleExtradata> object for this plugin and the given article.
+	 */
+	final protected function get_article_extradata($article)
+	{
+		return new ArticleExtradata($article->get_id(), $this->id);
+	}
+	
+	/*
 	 * Function: prepare_backend_pluginpage
 	 * Automatically sets the page title and highlights the menu-entry of your backend subpage.
 	 */
diff --git a/ratatoeskr/templates/src/systemtemplates/content_write.html b/ratatoeskr/templates/src/systemtemplates/content_write.html
index 82c86c4..3d63c61 100644
--- a/ratatoeskr/templates/src/systemtemplates/content_write.html
+++ b/ratatoeskr/templates/src/systemtemplates/content_write.html
@@ -49,6 +49,11 @@
 				</select>
 			</p>
 			<p><ste:get_translation for="allow_comments" />: <input type="checkbox" name="allow_comments" value="yes" ?{$allow_comments|checked="checked" |}/></p>
+			
+			<ste:foreach array="displayed_plugins" value="plugin">
+				<h2><ste:escape>$plugin[label]</ste:escape></h2>
+				<ste:load name="$plugin[template]" />
+			</ste:foreach>
 		</div>
 		
 		<div class="column_main">