diff --git a/admin/code/CMSBatchActionHandler.php b/admin/code/CMSBatchActionHandler.php
index 4bc6c4f3b..23ee16129 100644
--- a/admin/code/CMSBatchActionHandler.php
+++ b/admin/code/CMSBatchActionHandler.php
@@ -68,7 +68,7 @@ class CMSBatchActionHandler extends RequestHandler {
 
 	function handleAction($request) {
 		// This method can't be called without ajax.
-		if(!$this->parentController->isAjax()) {
+		if(!$request->isAjax()) {
 			$this->parentController->redirectBack();
 			return;
 		}
diff --git a/admin/code/LeftAndMain.php b/admin/code/LeftAndMain.php
index b93a468f0..35ea95489 100644
--- a/admin/code/LeftAndMain.php
+++ b/admin/code/LeftAndMain.php
@@ -193,7 +193,7 @@ class LeftAndMain extends Controller implements PermissionProvider {
 		if(Director::redirected_to()) return;
 
 		// Audit logging hook
-		if(empty($_REQUEST['executeForm']) && !$this->isAjax()) $this->extend('accessedCMS');
+		if(empty($_REQUEST['executeForm']) && !$this->request->isAjax()) $this->extend('accessedCMS');
 		
 		// Set the members html editor config
 		HtmlEditorConfig::set_active(Member::currentUser()->getHtmlEditorConfigForCMS());
@@ -341,7 +341,7 @@ class LeftAndMain extends Controller implements PermissionProvider {
 	}
 
 	function index($request) {
-		return ($this->isAjax()) ? $this->show($request) : $this->getViewer('index')->process($this);
+		return ($request->isAjax()) ? $this->show($request) : $this->getViewer('index')->process($this);
 	}
 
 	
diff --git a/control/Controller.php b/control/Controller.php
index 0f7b124e3..8071387dd 100644
--- a/control/Controller.php
+++ b/control/Controller.php
@@ -535,17 +535,6 @@ class Controller extends RequestHandler implements TemplateGlobalProvider {
 		$this->session = $session;
 	}
 	
-	/**
-	 * Returns true if this controller is processing an ajax request
-	 * @return boolean True if this controller is processing an ajax request
-	 */
-	function isAjax() {
-		return (
-			isset($this->requestParams['ajax']) || isset($_REQUEST['ajax']) ||
-			(isset($_SERVER['HTTP_X_REQUESTED_WITH']) && $_SERVER['HTTP_X_REQUESTED_WITH'] == "XMLHttpRequest")
-		);
-	}
-	
 	/**
 	 * Joins two or more link segments together, putting a slash between them if necessary.
 	 * Use this for building the results of {@link Link()} methods.
diff --git a/control/Director.php b/control/Director.php
index 9c2b33745..980fa3588 100644
--- a/control/Director.php
+++ b/control/Director.php
@@ -682,7 +682,7 @@ class Director implements TemplateGlobalProvider {
 	 */
 	static function is_ajax() {
 		if(Controller::has_curr()) {
-			return Controller::curr()->isAjax();
+			return Controller::curr()->getRequest()->isAjax();
 		} else {
 			return (
 				isset($_REQUEST['ajax']) ||
diff --git a/control/HTTPRequest.php b/control/HTTPRequest.php
index 06bc90063..8a34ba3ad 100644
--- a/control/HTTPRequest.php
+++ b/control/HTTPRequest.php
@@ -232,6 +232,20 @@ class SS_HTTPRequest implements ArrayAccess {
 	function getURL() {
 		return ($this->getExtension()) ? $this->url . '.' . $this->getExtension() : $this->url; 
 	}
+
+	/**
+	 * Returns true if this request an ajax request,
+	 * based on custom HTTP ajax added by common JavaScript libraries,
+	 * or based on an explicit "ajax" request parameter.
+	 * 
+	 * @return boolean
+	 */
+	function isAjax() {
+		return (
+			$this->requestVar('ajax') ||
+			$this->getHeader('X-Requested-With') && $this->getHeader('X-Requested-With') == "XMLHttpRequest"
+		);
+	}
 	
 	/**
 	 * Enables the existence of a key-value pair in the request to be checked using
diff --git a/control/RequestHandler.php b/control/RequestHandler.php
index 73a5bc1dc..6167e19bb 100644
--- a/control/RequestHandler.php
+++ b/control/RequestHandler.php
@@ -338,6 +338,59 @@ class RequestHandler extends ViewableData {
 
 		throw $e;
 	}
+
+	/**
+	 * @deprecated 3.0 Use SS_HTTPRequest->isAjax() instead (through Controller->getRequest())
+	 */
+	function isAjax() {
+		Deprecation::notice('3.0', 'Use SS_HTTPRequest->isAjax() instead (through Controller->getRequest())');
+		return $this->request->isAjax();
+	}
+
+	/**
+	 * Handle the X-Get-Fragment header that AJAX responses may provide, returning the 
+	 * fragment, or, in the case of non-AJAX form submissions, redirecting back to the submitter.
+	 *
+	 * X-Get-Fragment ensures that users won't end up seeing the unstyled form HTML in their browser
+	 * If a JS error prevents the Ajax overriding of form submissions from happening. It also provides
+	 * better non-JS operation.
+	 * 
+	 * Out of the box, the handler "CurrentForm" value, which will return the rendered form.  Non-Ajax
+	 * calls will redirect back.
+	 * 
+	 * To extend its responses, pass a map to the $options argument.  Each key is the value of X-Get-Fragment
+	 * that will work, and the value is a PHP 'callable' value that will return the response for that
+	 * value.
+	 * 
+	 * If you specify $options['default'], this will be used as the non-ajax response.
+	 * 
+	 * Note that if you use handleFragmentResponse, then any Ajax requests will have to include X-Get-Fragment
+	 * or an error will be thrown.
+	 */
+	function handleFragmentResponse($form, $options = array()) {
+		// Prepare the default options and combine with the others
+		$lOptions = array(
+			'currentform' => array($form, 'forTemplate'),
+			'default' => array('Director', 'redirectBack'),
+		);
+		if($options) foreach($options as $k => $v) {
+			$lOptions[strtolower($k)] = $v;
+		}
+		
+		if($fragment = $this->request->getHeader('X-Get-Fragment')) {
+			$fragment = strtolower($fragment);
+			if(isset($lOptions[$fragment])) {
+				return call_user_func($lOptions[$fragment]);
+			} else {
+				throw new SS_HTTPResponse_Exception("X-Get-Fragment = '$fragment' not supported for this URL.", 400);
+			}
+			
+		} else {
+			if($this->isAjax()) throw new SS_HTTPResponse_Exception("Ajax requests to this URL require an X-Get-Fragment header.", 400);
+			return call_user_func($lOptions['default']);
+		}
+		
+	}
 	
 	/**
 	 * Returns the SS_HTTPRequest object that this controller is using.
diff --git a/forms/gridfield/GridFieldDetailForm.php b/forms/gridfield/GridFieldDetailForm.php
index a3585a2e3..58bd39d5c 100755
--- a/forms/gridfield/GridFieldDetailForm.php
+++ b/forms/gridfield/GridFieldDetailForm.php
@@ -196,7 +196,7 @@ class GridFieldDetailForm_ItemRequest extends RequestHandler {
 			'ItemEditForm' => $form,
 		))->renderWith($this->template);
 
-		if($controller->isAjax()) {
+		if($request->isAjax()) {
 			return $return;	
 		} else {
 			// If not requested by ajax, we need to render it within the controller context+template
diff --git a/tests/control/HTTPRequestTest.php b/tests/control/HTTPRequestTest.php
index 4ae6b1b0a..fa92643f1 100644
--- a/tests/control/HTTPRequestTest.php
+++ b/tests/control/HTTPRequestTest.php
@@ -230,4 +230,16 @@ class HTTPRequestTest extends SapphireTest {
 			'Nested GET parameters should supplement POST parameters'
 		);
 	}
+
+	function testIsAjax() {
+		$req = new SS_HTTPRequest('GET', '/', array('ajax' => 0));
+		$this->assertFalse($req->isAjax());
+
+		$req = new SS_HTTPRequest('GET', '/', array('ajax' => 1));
+		$this->assertTrue($req->isAjax());
+
+		$req = new SS_HTTPRequest('GET', '/');
+		$req->addHeader('X-Requested-With', 'XMLHttpRequest');
+		$this->assertTrue($req->isAjax());
+	}
 }