Index: branches/RC/core/kernel/db/dbitem.php
===================================================================
diff -u -r10122 -r10294
--- branches/RC/core/kernel/db/dbitem.php	(.../dbitem.php)	(revision 10122)
+++ branches/RC/core/kernel/db/dbitem.php	(.../dbitem.php)	(revision 10294)
@@ -77,9 +77,22 @@
 		return $this->DirtyFieldValues[$field_name];
 	}
 
-	function GetOriginalField($field_name)
+	function GetOriginalField($field_name, $formatted = false, $format=null)
 	{
-		return $this->OriginalFieldValues[$field_name];
+		$value = $this->OriginalFieldValues[$field_name];
+		if (!$formatted) {
+			return $value;
+		}
+
+		$options = $this->GetFieldOptions($field_name);
+		$res = $value;
+		if (array_key_exists('formatter', $options)) {
+			$formatter =& $this->Application->recallObject($options['formatter']);
+			/* @var $formatter kFormatter */
+
+			$res = $formatter->Format($value, $field_name, $this, $format);
+		}
+		return $res;
 	}
 
 	/**
@@ -419,7 +432,7 @@
 
 		$affected = $this->Conn->getAffectedRows();
 		if (!$system_update && $affected == 1){
-			$this->setModifiedFlag();
+			$this->setModifiedFlag(clUPDATE);
 		}
 
 		$this->saveCustomFields();
@@ -772,7 +785,7 @@
 		$this->setID($insert_id);
 
 		if (!$system_create){
-			$this->setModifiedFlag();
+			$this->setModifiedFlag(clCREATE);
 		}
 
 		$this->saveCustomFields();
@@ -800,7 +813,7 @@
 
 		$ret = $this->Conn->ChangeQuery($q);
 
-		$this->setModifiedFlag();
+		$this->setModifiedFlag(clDELETE);
 
 		if ($this->Conn->getAffectedRows() > 0) {
 			// something was actually deleted
@@ -929,6 +942,22 @@
 		--$new_id;
 
 		$this->Conn->Query('UPDATE '.$this->TableName.' SET `'.$this->IDField.'` = '.$new_id.' WHERE `'.$this->IDField.'` = '.$this->GetID());
+
+		if ($this->ShouldLogChanges()) {
+			// Updating TempId in ChangesLog, if changes are disabled
+			$ses_var_name = $this->Application->GetTopmostPrefix($this->Prefix).'_changes_'.$this->Application->GetTopmostWid($this->Prefix);
+			$changes = $this->Application->RecallVar($ses_var_name);
+			$changes = $changes ? unserialize($changes) : Array ();
+			if ($changes) {
+				foreach ($changes as $key => $rec) {
+					if ($rec['Prefix'] == $this->Prefix && $rec['ItemId'] == $this->GetID()) {
+						$changes[$key]['ItemId'] = $new_id;
+					}
+				}
+			}
+			$this->Application->StoreVar($ses_var_name, serialize($changes));
+		}
+
 		$this->SetID($new_id);
 	}
 
@@ -938,12 +967,99 @@
 	 * @access private
 	 * @author Alexey
 	 */
-	function setModifiedFlag()
+	function setModifiedFlag($mode = null)
 	{
 		$main_prefix = $this->Application->GetTopmostPrefix($this->Prefix);
 		$this->Application->StoreVar($main_prefix.'_modified', '1');
+
+		if ($this->ShouldLogChanges()) {
+			$this->LogChanges($main_prefix, $mode);
+			if (!$this->IsTempTable()) {
+				$handler =& $this->Application->recallObject($this->Prefix.'_EventHandler');
+				$ses_var_name = $main_prefix.'_changes_'.$this->Application->GetTopmostWid($this->Prefix);
+				$handler->SaveLoggedChanges($ses_var_name);
+			}
+		}
 	}
 
+	function ShouldLogChanges()
+	{
+		/* @todo Replace true with global LogChanges option */
+		return ($this->Application->getUnitOption($this->Prefix, 'LogChanges') || true) && !$this->Application->getUnitOption($this->Prefix, 'ForceDontLogChanges');
+	}
+
+	function LogChanges($main_prefix, $mode)
+	{
+		if (!$mode) {
+			return ;
+		}
+
+		$ses_var_name = $main_prefix.'_changes_'.$this->Application->GetTopmostWid($this->Prefix);
+		$changes = $this->Application->RecallVar($ses_var_name);
+		$changes = $changes ? unserialize($changes) : array();
+
+		$general = array(
+			'Prefix' => $this->Prefix,
+			'ItemId' => $this->GetID(),
+			'OccuredOn' => adodb_mktime(),
+			'MasterPrefix' => $main_prefix,
+			'MasterId' => $this->Prefix == $main_prefix ? $this->GetID() : $this->Application->GetVar($main_prefix.'_id'), // is that correct (Kostja)??
+			'Action' => $mode,
+		);
+		switch ($mode) {
+			case clUPDATE:
+				$changes[] = array_merge($general, Array(
+					'Changes' => serialize(array_merge($this->GetTitleField(), $this->GetChangedFields())),
+				));
+				break;
+			case clCREATE:
+				$changes[] = array_merge($general, Array(
+					'Changes' => serialize($this->GetTitleField()),
+				));
+				break;
+			case clDELETE:
+				$changes[] = array_merge($general, Array(
+					'Changes' => serialize(array_merge($this->GetTitleField(), $this->GetRealFields())),
+				));
+		}
+
+		$this->Application->StoreVar($ses_var_name, serialize($changes));
+	}
+
+	function GetTitleField()
+	{
+		$title_field = $this->Application->getUnitOption($this->Prefix, 'TitleField');
+		if ($title_field && $this->GetField($title_field)) {
+			return Array($title_field => $this->GetField($title_field));
+		}
+	}
+
+	function GetRealFields()
+	{
+		if (function_exists('array_diff_key')) {
+			$db_fields = array_diff_key($this->FieldValues, $this->VirtualFields, $this->CalculatedFields);
+		}
+		else {
+			$db_fields = array();
+			foreach ($this->FieldValues as $key => $value) {
+				if (array_key_exists($key, $this->VirtualFields) || array_key_exists($key, $this->CalculatedFields)) continue;
+				$db_fields[$key] = $value;
+			}
+		}
+		return $db_fields;
+	}
+
+	function GetChangedFields()
+	{
+		$changes = array();
+
+		$diff = array_diff_assoc($this->GetRealFields(), $this->OriginalFieldValues);
+		foreach ($diff as $field => $new_value) {
+			$changes[$field] = array('old' => $this->GetOriginalField($field, true), 'new' => $this->GetField($field));
+		}
+		return $changes;
+	}
+
 	/**
 	 * Returns ID of currently processed record
 	 *