diff --git a/model/DataObject.php b/model/DataObject.php
index 8b0a817ae..afa4e4dfd 100644
--- a/model/DataObject.php
+++ b/model/DataObject.php
@@ -395,9 +395,12 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 	
 	/**
 	 * Set the DataModel
+	 * @param DataModel $model
+	 * @return DataObject $this
 	 */
 	public function setDataModel(DataModel $model) {
 		$this->model = $model;
+		return $this;
 	}
 
 	/**
@@ -503,6 +506,7 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 	 * or destroy and reinstanciate the record.
 	 *
 	 * @param string $className The new ClassName attribute (a subclass of {@link DataObject})
+	 * @return DataObject $this
 	 */
 	public function setClassName($className) {
 		$className = trim($className);
@@ -510,6 +514,7 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 
 		$this->class = $className;
 		$this->setField("ClassName", $className);
+		return $this;
 	}
 
 	/**
@@ -745,6 +750,7 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 	 * the related objects that it alters.
 	 *
 	 * @param array $data A map of field name to data values to update.
+	 * @return DataObject $this
 	 */
 	public function update($data) {
 		foreach($data as $k => $v) {
@@ -784,6 +790,7 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 				$this->$k = $v;
 			}
 		}
+		return $this;
 	}
 	
 	/**
@@ -793,11 +800,13 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 	 * use the write() method.
 	 *
 	 * @param array $data A map of field name to data values to update.
+	 * @return DataObject $this
 	 */
 	public function castedUpdate($data) {
 		foreach($data as $k => $v) {
 			$this->setCastedField($k,$v);
 		}
+		return $this;
 	}
 
 	/**
@@ -895,6 +904,8 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 	 * Forces the record to think that all its data has changed.
 	 * Doesn't write to the database. Only sets fields as changed
 	 * if they are not already marked as changed.
+	 * 
+	 * @return DataObject $this
 	 */
 	public function forceChange() {
 		// Ensure lazy fields loaded
@@ -913,6 +924,7 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 		
 		// @todo Find better way to allow versioned to write a new version after forceChange
 		if($this->isChanged('Version')) unset($this->changed['Version']);
+		return $this;
 	}
 	
 	/**
@@ -987,7 +999,8 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 	 * Will traverse the defaults of the current class and all its parent classes.
 	 * Called by the constructor when creating new records.
 	 * 
-	 *  @uses DataExtension->populateDefaults()
+	 * @uses DataExtension->populateDefaults()
+	 * @return DataObject $this
 	 */
 	public function populateDefaults() {
 		$classes = array_reverse(ClassInfo::ancestry($this));
@@ -1018,6 +1031,7 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 		}
 		
 		$this->extend('populateDefaults');
+		return $this;
 	}
 
 	/**
@@ -1235,13 +1249,15 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 	 * same record.
 	 *
 	 * @param $recursive Recursively write components
+	 * @return DataObject $this
 	 */
 	public function writeComponents($recursive = false) {
-		if(!$this->components) return;
+		if(!$this->components) return $this;
 		
 		foreach($this->components as $component) {
 			$component->write(false, false, false, $recursive);
 		}
+		return $this;
 	}
 	
 	/**
@@ -2230,6 +2246,7 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 	 *
 	 * @param string $fieldName Name of the field
 	 * @param mixed $val New field value
+	 * @return DataObject $this
 	 */
 	public function setField($fieldName, $val) {
 		// Situation 1: Passing an DBField
@@ -2273,6 +2290,7 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 				$this->record[$fieldName] = $val;
 			}
 		}
+		return $this;
 	}
 
 	/**
@@ -2283,6 +2301,7 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 	 *
 	 * @param string $fieldName Name of the field
 	 * @param mixed $value New field value
+	 * @return DataObject $this
 	 */
 	public function setCastedField($fieldName, $val) {
 		if(!$fieldName) {
@@ -2296,6 +2315,7 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 		} else {
 			$this->$fieldName = $val;
 		}
+		return $this;
 	}
 
 	/**
@@ -2832,14 +2852,14 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 	 *
 	 * @param boolean $persistent When true will also clear persistent data stored in the Cache system.
 	 *                            When false will just clear session-local cached data 
-	 *
+	 * @return DataObject $this
 	 */
 	public function flushCache($persistent = true) {
 		if($persistent) Aggregate::flushCache($this->class);
 		
 		if($this->class == 'DataObject') {
 			DataObject::$_cache_get_one = array();
-			return;
+			return $this;
 		}
 
 		$classes = ClassInfo::ancestry($this->class);
@@ -2850,6 +2870,7 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 		$this->extend('flushCache');
 		
 		$this->components = array();
+		return $this;
 	}
 
 	/**