From 803cd4b7cfa0e846d5fa89be04ef4140e6f1a7d2 Mon Sep 17 00:00:00 2001
From: Ms2ger <ms2ger@gmail.com>
Date: Sat, 9 Nov 2013 21:30:41 +0100
Subject: [PATCH] Make DOMString represent a non-nullable string.

---
 src/components/script/dom/attr.rs             | 14 +--
 .../dom/bindings/codegen/CodegenRust.py       | 10 +--
 src/components/script/dom/bindings/utils.rs   | 12 +--
 src/components/script/dom/characterdata.rs    | 12 +--
 src/components/script/dom/comment.rs          |  2 +-
 src/components/script/dom/document.rs         | 22 ++---
 src/components/script/dom/documenttype.rs     |  6 +-
 src/components/script/dom/domparser.rs        |  2 +-
 src/components/script/dom/element.rs          | 62 ++++++-------
 src/components/script/dom/event.rs            |  6 +-
 src/components/script/dom/eventtarget.rs      |  4 +-
 src/components/script/dom/formdata.rs         |  8 +-
 .../script/dom/htmlanchorelement.rs           | 52 +++++------
 .../script/dom/htmlappletelement.rs           | 36 ++++----
 src/components/script/dom/htmlareaelement.rs  | 28 +++---
 src/components/script/dom/htmlbaseelement.rs  |  8 +-
 src/components/script/dom/htmlbodyelement.rs  | 24 ++---
 src/components/script/dom/htmlbrelement.rs    |  4 +-
 .../script/dom/htmlbuttonelement.rs           | 34 +++----
 src/components/script/dom/htmlcollection.rs   |  4 +-
 src/components/script/dom/htmldataelement.rs  |  4 +-
 src/components/script/dom/htmldivelement.rs   |  4 +-
 src/components/script/dom/htmldlistelement.rs |  4 +-
 src/components/script/dom/htmlelement.rs      | 26 +++---
 src/components/script/dom/htmlembedelement.rs | 24 ++---
 .../script/dom/htmlfieldsetelement.rs         | 10 +--
 src/components/script/dom/htmlfontelement.rs  | 12 +--
 src/components/script/dom/htmlformelement.rs  | 32 +++----
 src/components/script/dom/htmlframeelement.rs | 28 +++---
 .../script/dom/htmlframesetelement.rs         |  8 +-
 .../script/dom/htmlheadingelement.rs          |  4 +-
 src/components/script/dom/htmlhrelement.rs    | 16 ++--
 src/components/script/dom/htmlhtmlelement.rs  |  4 +-
 .../script/dom/htmliframeelement.rs           | 50 +++++------
 src/components/script/dom/htmlimageelement.rs | 34 +++----
 src/components/script/dom/htmlinputelement.rs | 88 +++++++++----------
 src/components/script/dom/htmllabelelement.rs |  4 +-
 .../script/dom/htmllegendelement.rs           |  4 +-
 src/components/script/dom/htmllielement.rs    |  4 +-
 src/components/script/dom/htmllinkelement.rs  | 36 ++++----
 src/components/script/dom/htmlmapelement.rs   |  4 +-
 src/components/script/dom/htmlmediaelement.rs | 16 ++--
 src/components/script/dom/htmlmetaelement.rs  | 16 ++--
 src/components/script/dom/htmlmodelement.rs   |  8 +-
 .../script/dom/htmlobjectelement.rs           | 56 ++++++------
 src/components/script/dom/htmlolistelement.rs |  4 +-
 .../script/dom/htmloptgroupelement.rs         |  4 +-
 .../script/dom/htmloptionelement.rs           | 12 +--
 .../script/dom/htmloutputelement.rs           | 20 ++---
 .../script/dom/htmlparagraphelement.rs        |  4 +-
 src/components/script/dom/htmlparamelement.rs | 16 ++--
 src/components/script/dom/htmlquoteelement.rs |  4 +-
 .../script/dom/htmlscriptelement.rs           | 28 +++---
 .../script/dom/htmlselectelement.rs           | 18 ++--
 .../script/dom/htmlsourceelement.rs           | 12 +--
 src/components/script/dom/htmlstyleelement.rs |  8 +-
 .../script/dom/htmltablecaptionelement.rs     |  4 +-
 .../script/dom/htmltablecellelement.rs        | 44 +++++-----
 .../script/dom/htmltablecolelement.rs         | 20 ++---
 src/components/script/dom/htmltableelement.rs | 36 ++++----
 .../script/dom/htmltablerowelement.rs         | 20 ++---
 .../script/dom/htmltablesectionelement.rs     | 16 ++--
 .../script/dom/htmltextareaelement.rs         | 34 +++----
 src/components/script/dom/htmltimeelement.rs  |  4 +-
 src/components/script/dom/htmltitleelement.rs |  4 +-
 src/components/script/dom/htmltrackelement.rs | 16 ++--
 src/components/script/dom/htmlulistelement.rs |  4 +-
 src/components/script/dom/htmlvideoelement.rs |  4 +-
 src/components/script/dom/mouseevent.rs       |  6 +-
 src/components/script/dom/namespace.rs        |  4 +-
 src/components/script/dom/navigator.rs        | 24 ++---
 src/components/script/dom/node.rs             | 24 ++---
 src/components/script/dom/text.rs             |  4 +-
 src/components/script/dom/uievent.rs          |  4 +-
 src/components/script/dom/window.rs           | 16 ++--
 75 files changed, 632 insertions(+), 632 deletions(-)

diff --git a/src/components/script/dom/attr.rs b/src/components/script/dom/attr.rs
index 310dc2f3de6..03d6a2e8d9f 100644
--- a/src/components/script/dom/attr.rs
+++ b/src/components/script/dom/attr.rs
@@ -16,7 +16,7 @@ pub struct Attr {
     value: ~str,
     name: ~str,
     namespace: Namespace,
-    prefix: DOMString
+    prefix: Option<DOMString>
 }
 
 impl Reflectable for Attr {
@@ -69,27 +69,27 @@ impl Attr {
         }
     }
 
-    pub fn LocalName(&self) -> DOMString {
+    pub fn LocalName(&self) -> Option<DOMString> {
         Some(self.local_name().to_owned())
     }
 
-    pub fn Value(&self) -> DOMString {
+    pub fn Value(&self) -> Option<DOMString> {
         Some(self.value.clone())
     }
 
-    pub fn SetValue(&mut self, value: &DOMString) {
+    pub fn SetValue(&mut self, value: &Option<DOMString>) {
         self.value = null_str_as_empty(value);
     }
 
-    pub fn Name(&self) -> DOMString {
+    pub fn Name(&self) -> Option<DOMString> {
         Some(self.name.clone())
     }
 
-    pub fn GetNamespaceURI(&self) -> DOMString {
+    pub fn GetNamespaceURI(&self) -> Option<DOMString> {
         self.namespace.to_str()
     }
 
-    pub fn GetPrefix(&self) -> DOMString {
+    pub fn GetPrefix(&self) -> Option<DOMString> {
         self.prefix.clone()
     }
 }
diff --git a/src/components/script/dom/bindings/codegen/CodegenRust.py b/src/components/script/dom/bindings/codegen/CodegenRust.py
index 9f333ca6e75..c1739f1c13c 100644
--- a/src/components/script/dom/bindings/codegen/CodegenRust.py
+++ b/src/components/script/dom/bindings/codegen/CodegenRust.py
@@ -1110,10 +1110,10 @@ for (uint32_t i = 0; i < length; ++i) {
                 declType, None, isOptional, None)
 
         if isOptional:
-            declType = "Option<DOMString>"
+            declType = "Option<Option<DOMString>>"
             initialValue = "None"
         else:
-            declType = "DOMString"
+            declType = "Option<DOMString>"
             initialValue = None
 
         return (
@@ -1722,7 +1722,7 @@ def getRetvalDeclarationForType(returnType, descriptorProvider,
             result = CGWrapper(result, pre="Nullable<", post=">")
         return result, False
     if returnType.isString():
-        return CGGeneric("DOMString"), False
+        return CGGeneric("Option<DOMString>"), False
     if returnType.isEnum():
         if returnType.nullable():
             raise TypeError("We don't support nullable enum return values")
@@ -2960,8 +2960,8 @@ class CGCallGenerator(CGThing):
             if a.type.isObject() and not a.type.nullable() and not a.optional:
                 name = "(JSObject&)" + name
             #XXXjdm Perhaps we should pass all nontrivial types by borrowed pointer
-            # Aoid passing Option<DOMString> by reference. If only one of optional or
-            # defaultValue are truthy we pass an Option, otherwise it's a concrete DOMString.
+            # Aoid passing Option<Option<DOMString>> by reference. If only one of optional or
+            # defaultValue are truthy we pass an Option, otherwise it's a concrete Option<DOMString>.
             if a.type.isDictionary() or (a.type.isString() and not (bool(a.defaultValue) ^ a.optional)):
                 name = "&" + name
             args.append(CGGeneric(name))
diff --git a/src/components/script/dom/bindings/utils.rs b/src/components/script/dom/bindings/utils.rs
index 6fa2a8ec0c3..61b6ad54776 100644
--- a/src/components/script/dom/bindings/utils.rs
+++ b/src/components/script/dom/bindings/utils.rs
@@ -116,9 +116,9 @@ extern fn InterfaceObjectToString(cx: *JSContext, _argc: c_uint, vp: *mut JSVal)
   }
 }
 
-pub type DOMString = Option<~str>;
+pub type DOMString = ~str;
 
-pub fn null_str_as_empty(s: &DOMString) -> ~str {
+pub fn null_str_as_empty(s: &Option<DOMString>) -> ~str {
     // We don't use map_default because it would allocate ~"" even for Some.
     match *s {
         Some(ref s) => s.clone(),
@@ -126,14 +126,14 @@ pub fn null_str_as_empty(s: &DOMString) -> ~str {
     }
 }
 
-pub fn null_str_as_empty_ref<'a>(s: &'a DOMString) -> &'a str {
+pub fn null_str_as_empty_ref<'a>(s: &'a Option<DOMString>) -> &'a str {
     match *s {
         Some(ref s) => s.as_slice(),
         None => &'a ""
     }
 }
 
-pub fn null_str_as_word_null(s: &DOMString) -> ~str {
+pub fn null_str_as_word_null(s: &Option<DOMString>) -> ~str {
     // We don't use map_default because it would allocate ~"null" even for Some.
     match *s {
         Some(ref s) => s.clone(),
@@ -259,7 +259,7 @@ pub fn jsval_to_str(cx: *JSContext, v: JSVal,
 }
 
 #[fixed_stack_segment]
-pub fn jsval_to_domstring(cx: *JSContext, v: JSVal) -> Result<DOMString, ()> {
+pub fn jsval_to_domstring(cx: *JSContext, v: JSVal) -> Result<Option<DOMString>, ()> {
     if jsval::is_null(v) || jsval::is_undefined(v) {
         Ok(None)
     } else {
@@ -273,7 +273,7 @@ pub fn jsval_to_domstring(cx: *JSContext, v: JSVal) -> Result<DOMString, ()> {
 }
 
 #[fixed_stack_segment]
-pub unsafe fn domstring_to_jsval(cx: *JSContext, string: &DOMString) -> JSVal {
+pub unsafe fn domstring_to_jsval(cx: *JSContext, string: &Option<DOMString>) -> JSVal {
     match string {
         &None => JSVAL_NULL,
         &Some(ref s) => do s.to_utf16().as_imm_buf |buf, len| {
diff --git a/src/components/script/dom/characterdata.rs b/src/components/script/dom/characterdata.rs
index f84ebbbdb50..ad4dc67ee1c 100644
--- a/src/components/script/dom/characterdata.rs
+++ b/src/components/script/dom/characterdata.rs
@@ -22,11 +22,11 @@ impl CharacterData {
         }
     }
     
-    pub fn Data(&self) -> DOMString {
+    pub fn Data(&self) -> Option<DOMString> {
         Some(self.data.clone())
     }
 
-    pub fn SetData(&mut self, arg: &DOMString) -> ErrorResult {
+    pub fn SetData(&mut self, arg: &Option<DOMString>) -> ErrorResult {
         self.data = arg.get_ref().clone();
         Ok(())
     }
@@ -35,16 +35,16 @@ impl CharacterData {
         self.data.len() as u32
     }
 
-    pub fn SubstringData(&self, offset: u32, count: u32) -> Fallible<DOMString> {
+    pub fn SubstringData(&self, offset: u32, count: u32) -> Fallible<Option<DOMString>> {
         Ok(Some(self.data.slice(offset as uint, count as uint).to_str()))
     }
 
-    pub fn AppendData(&mut self, arg: &DOMString) -> ErrorResult {
+    pub fn AppendData(&mut self, arg: &Option<DOMString>) -> ErrorResult {
         self.data.push_str(arg.get_ref().clone());
         Ok(())
     }
 
-    pub fn InsertData(&mut self, _offset: u32, _arg: &DOMString) -> ErrorResult {
+    pub fn InsertData(&mut self, _offset: u32, _arg: &Option<DOMString>) -> ErrorResult {
         fail!("CharacterData::InsertData() is unimplemented")
     }
 
@@ -52,7 +52,7 @@ impl CharacterData {
         fail!("CharacterData::DeleteData() is unimplemented")
     }
 
-    pub fn ReplaceData(&mut self, _offset: u32, _count: u32, _arg: &DOMString) -> ErrorResult {
+    pub fn ReplaceData(&mut self, _offset: u32, _count: u32, _arg: &Option<DOMString>) -> ErrorResult {
         fail!("CharacterData::ReplaceData() is unimplemented")
     }
 }
diff --git a/src/components/script/dom/comment.rs b/src/components/script/dom/comment.rs
index bd238af7b50..6971cef2ead 100644
--- a/src/components/script/dom/comment.rs
+++ b/src/components/script/dom/comment.rs
@@ -26,7 +26,7 @@ impl Comment {
         Node::reflect_node(@mut node, document, CommentBinding::Wrap)
     }
 
-    pub fn Constructor(owner: @mut Window, data: &DOMString) -> Fallible<AbstractNode<ScriptView>> {
+    pub fn Constructor(owner: @mut Window, data: &Option<DOMString>) -> Fallible<AbstractNode<ScriptView>> {
         Ok(Comment::new(null_str_as_empty(data), owner.Document()))
     }
 }
diff --git a/src/components/script/dom/document.rs b/src/components/script/dom/document.rs
index e7542fc8975..15d68e2cc8f 100644
--- a/src/components/script/dom/document.rs
+++ b/src/components/script/dom/document.rs
@@ -180,19 +180,19 @@ impl Document {
         self.window.get_cx()
     }
 
-    pub fn GetElementsByTagName(&self, tag: &DOMString) -> @mut HTMLCollection {
+    pub fn GetElementsByTagName(&self, tag: &Option<DOMString>) -> @mut HTMLCollection {
         self.createHTMLCollection(|elem| eq_slice(elem.tag_name, null_str_as_empty(tag)))
     }
 
-    pub fn GetElementsByTagNameNS(&self, _ns: &DOMString, _tag: &DOMString) -> @mut HTMLCollection {
+    pub fn GetElementsByTagNameNS(&self, _ns: &Option<DOMString>, _tag: &Option<DOMString>) -> @mut HTMLCollection {
         HTMLCollection::new(self.window, ~[])
     }
 
-    pub fn GetElementsByClassName(&self, _class: &DOMString) -> @mut HTMLCollection {
+    pub fn GetElementsByClassName(&self, _class: &Option<DOMString>) -> @mut HTMLCollection {
         HTMLCollection::new(self.window, ~[])
     }
 
-    pub fn GetElementById(&self, id: &DOMString) -> Option<AbstractNode<ScriptView>> {
+    pub fn GetElementById(&self, id: &Option<DOMString>) -> Option<AbstractNode<ScriptView>> {
         let key: &~str = &null_str_as_empty(id);
         // TODO: "in tree order, within the context object's tree"
         // http://dom.spec.whatwg.org/#dom-document-getelementbyid.
@@ -202,7 +202,7 @@ impl Document {
         }
     }
 
-    pub fn CreateElement(&self, abstract_self: AbstractDocument, local_name: &DOMString) -> Fallible<AbstractNode<ScriptView>> {
+    pub fn CreateElement(&self, abstract_self: AbstractDocument, local_name: &Option<DOMString>) -> Fallible<AbstractNode<ScriptView>> {
         let local_name = null_str_as_empty(local_name);
         if xml_name_type(local_name) == InvalidXMLName {
             return Err(InvalidCharacter);
@@ -215,15 +215,15 @@ impl Document {
         DocumentFragment::new(abstract_self)
     }
 
-    pub fn CreateTextNode(&self, abstract_self: AbstractDocument, data: &DOMString) -> AbstractNode<ScriptView> {
+    pub fn CreateTextNode(&self, abstract_self: AbstractDocument, data: &Option<DOMString>) -> AbstractNode<ScriptView> {
         Text::new(null_str_as_empty(data), abstract_self)
     }
 
-    pub fn CreateComment(&self, abstract_self: AbstractDocument, data: &DOMString) -> AbstractNode<ScriptView> {
+    pub fn CreateComment(&self, abstract_self: AbstractDocument, data: &Option<DOMString>) -> AbstractNode<ScriptView> {
         Comment::new(null_str_as_word_null(data), abstract_self)
     }
 
-    pub fn CreateEvent(&self, interface: &DOMString) -> Fallible<AbstractEvent> {
+    pub fn CreateEvent(&self, interface: &Option<DOMString>) -> Fallible<AbstractEvent> {
         match null_str_as_empty_ref(interface) {
             "UIEvents" => Ok(UIEvent::new(self.window, UIEventTypeId)),
             "MouseEvents" => Ok(MouseEvent::new(self.window)),
@@ -232,7 +232,7 @@ impl Document {
         }
     }
 
-    pub fn Title(&self, _: AbstractDocument) -> DOMString {
+    pub fn Title(&self, _: AbstractDocument) -> Option<DOMString> {
         let mut title = ~"";
         match self.doctype {
             SVG => {
@@ -266,7 +266,7 @@ impl Document {
         Some(title)
     }
 
-    pub fn SetTitle(&self, abstract_self: AbstractDocument, title: &DOMString) -> ErrorResult {
+    pub fn SetTitle(&self, abstract_self: AbstractDocument, title: &Option<DOMString>) -> ErrorResult {
         match self.doctype {
             SVG => {
                 fail!("no SVG document yet")
@@ -305,7 +305,7 @@ impl Document {
         Ok(())
     }
 
-    pub fn GetElementsByName(&self, name: &DOMString) -> @mut HTMLCollection {
+    pub fn GetElementsByName(&self, name: &Option<DOMString>) -> @mut HTMLCollection {
         self.createHTMLCollection(|elem|
             elem.get_attr("name").is_some() && eq_slice(elem.get_attr("name").unwrap(), null_str_as_empty(name)))
     }
diff --git a/src/components/script/dom/documenttype.rs b/src/components/script/dom/documenttype.rs
index 463ddcfa239..797a75ea04c 100644
--- a/src/components/script/dom/documenttype.rs
+++ b/src/components/script/dom/documenttype.rs
@@ -47,15 +47,15 @@ impl DocumentType {
 }
 
 impl DocumentType {
-    pub fn Name(&self) -> DOMString {
+    pub fn Name(&self) -> Option<DOMString> {
         Some(self.name.clone())
     }
 
-    pub fn PublicId(&self) -> DOMString {
+    pub fn PublicId(&self) -> Option<DOMString> {
         self.public_id.clone()
     }
 
-    pub fn SystemId(&self) -> DOMString {
+    pub fn SystemId(&self) -> Option<DOMString> {
         self.system_id.clone()
     }
 }
diff --git a/src/components/script/dom/domparser.rs b/src/components/script/dom/domparser.rs
index 7fc874d05d1..6c657daf170 100644
--- a/src/components/script/dom/domparser.rs
+++ b/src/components/script/dom/domparser.rs
@@ -33,7 +33,7 @@ impl DOMParser {
     }
 
     pub fn ParseFromString(&self,
-                           _s: &DOMString,
+                           _s: &Option<DOMString>,
                            ty: DOMParserBinding::SupportedType)
                            -> Fallible<AbstractDocument> {
         match ty {
diff --git a/src/components/script/dom/element.rs b/src/components/script/dom/element.rs
index d0baf973bc9..a3d4257b393 100644
--- a/src/components/script/dom/element.rs
+++ b/src/components/script/dom/element.rs
@@ -154,7 +154,7 @@ impl<'self> Element {
         }
     }
 
-    pub fn normalize_attr_name(&self, name: &DOMString) -> ~str {
+    pub fn normalize_attr_name(&self, name: &Option<DOMString>) -> ~str {
         //FIXME: Throw for XML-invalid names
         let owner = self.node.owner_doc();
         if owner.document().doctype == document::HTML { // && self.namespace == Namespace::HTML
@@ -165,7 +165,7 @@ impl<'self> Element {
     }
 
     pub fn get_attribute<'a>(&'a self,
-                         namespace_url: &DOMString,
+                         namespace_url: &Option<DOMString>,
                          name: &str) -> Option<@mut Attr> {
         let namespace = Namespace::from_str(namespace_url);
         // FIXME: only case-insensitive in the HTML namespace (as opposed to SVG, etc.)
@@ -179,16 +179,16 @@ impl<'self> Element {
 
     pub fn set_attr(&mut self,
                     abstract_self: AbstractNode<ScriptView>,
-                    raw_name: &DOMString,
-                    raw_value: &DOMString) -> ErrorResult {
+                    raw_name: &Option<DOMString>,
+                    raw_value: &Option<DOMString>) -> ErrorResult {
         self.set_attribute(abstract_self, namespace::Null, raw_name, raw_value)
     }
 
     pub fn set_attribute(&mut self,
                          abstract_self: AbstractNode<ScriptView>,
                          namespace: Namespace,
-                         raw_name: &DOMString,
-                         raw_value: &DOMString) -> ErrorResult {
+                         raw_name: &Option<DOMString>,
+                         raw_value: &Option<DOMString>) -> ErrorResult {
         //FIXME: Throw for XML-invalid names
         //FIXME: Throw for XMLNS-invalid names
         let name = null_str_as_empty(raw_name).to_ascii_lower();
@@ -246,7 +246,7 @@ impl<'self> Element {
                       abstract_self: AbstractNode<ScriptView>,
                       namespace: &Namespace,
                       local_name: ~str,
-                      value: &DOMString) {
+                      value: &Option<DOMString>) {
 
         if "style" == local_name && *namespace == namespace::Null {
              self.style_attribute = Some(style::parse_style_attribute(
@@ -280,43 +280,43 @@ impl<'self> Element {
 }
 
 impl Element {
-    pub fn TagName(&self) -> DOMString {
+    pub fn TagName(&self) -> Option<DOMString> {
         Some(self.tag_name.to_owned().to_ascii_upper())
     }
 
-    pub fn Id(&self, _abstract_self: AbstractNode<ScriptView>) -> DOMString {
+    pub fn Id(&self, _abstract_self: AbstractNode<ScriptView>) -> Option<DOMString> {
         match self.get_attr(&"id") {
             Some(x) => Some(x),
             None => Some(~"")
         }
     }
 
-    pub fn SetId(&mut self, abstract_self: AbstractNode<ScriptView>, id: &DOMString) {
+    pub fn SetId(&mut self, abstract_self: AbstractNode<ScriptView>, id: &Option<DOMString>) {
         self.set_attribute(abstract_self, namespace::Null, &Some(~"id"), id);
     }
 
-    pub fn GetAttribute(&self, name: &DOMString) -> DOMString {
+    pub fn GetAttribute(&self, name: &Option<DOMString>) -> Option<DOMString> {
         self.get_attr(null_str_as_empty_ref(name))
     }
 
-    pub fn GetAttributeNS(&self, namespace: &DOMString, local_name: &DOMString) -> DOMString {
+    pub fn GetAttributeNS(&self, namespace: &Option<DOMString>, local_name: &Option<DOMString>) -> Option<DOMString> {
         self.get_attribute(namespace, null_str_as_empty_ref(local_name))
             .map(|attr| attr.value.clone())
     }
 
     pub fn SetAttribute(&mut self,
                         abstract_self: AbstractNode<ScriptView>,
-                        name: &DOMString,
-                        value: &DOMString) -> ErrorResult {
+                        name: &Option<DOMString>,
+                        value: &Option<DOMString>) -> ErrorResult {
         self.set_attr(abstract_self, name, value);
         Ok(())
     }
 
     pub fn SetAttributeNS(&mut self,
                           abstract_self: AbstractNode<ScriptView>,
-                          namespace_url: &DOMString,
-                          name: &DOMString,
-                          value: &DOMString) -> ErrorResult {
+                          namespace_url: &Option<DOMString>,
+                          name: &Option<DOMString>,
+                          value: &Option<DOMString>) -> ErrorResult {
         let name_type = xml_name_type(name.to_str());
         match name_type {
             InvalidXMLName => return Err(InvalidCharacter),
@@ -328,35 +328,35 @@ impl Element {
         self.set_attribute(abstract_self, namespace, name, value)
     }
 
-    pub fn RemoveAttribute(&self, _name: &DOMString) -> ErrorResult {
+    pub fn RemoveAttribute(&self, _name: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn RemoveAttributeNS(&self, _namespace: &DOMString, _localname: &DOMString) -> ErrorResult {
+    pub fn RemoveAttributeNS(&self, _namespace: &Option<DOMString>, _localname: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn HasAttribute(&self, name: &DOMString) -> bool {
+    pub fn HasAttribute(&self, name: &Option<DOMString>) -> bool {
         self.GetAttribute(name).is_some()
     }
 
-    pub fn HasAttributeNS(&self, namespace: &DOMString, local_name: &DOMString) -> bool {
+    pub fn HasAttributeNS(&self, namespace: &Option<DOMString>, local_name: &Option<DOMString>) -> bool {
         self.GetAttributeNS(namespace, local_name).is_some()
     }
 
-    pub fn GetElementsByTagName(&self, _localname: &DOMString) -> @mut HTMLCollection {
+    pub fn GetElementsByTagName(&self, _localname: &Option<DOMString>) -> @mut HTMLCollection {
         HTMLCollection::new(self.node.owner_doc().document().window, ~[])
     }
 
-    pub fn GetElementsByTagNameNS(&self, _namespace: &DOMString, _localname: &DOMString) -> Fallible<@mut HTMLCollection> {
+    pub fn GetElementsByTagNameNS(&self, _namespace: &Option<DOMString>, _localname: &Option<DOMString>) -> Fallible<@mut HTMLCollection> {
         Ok(HTMLCollection::new(self.node.owner_doc().document().window, ~[]))
     }
 
-    pub fn GetElementsByClassName(&self, _names: &DOMString) -> @mut HTMLCollection {
+    pub fn GetElementsByClassName(&self, _names: &Option<DOMString>) -> @mut HTMLCollection {
         HTMLCollection::new(self.node.owner_doc().document().window, ~[])
     }
 
-    pub fn MozMatchesSelector(&self, _selector: &DOMString) -> Fallible<bool> {
+    pub fn MozMatchesSelector(&self, _selector: &Option<DOMString>) -> Fallible<bool> {
         Ok(false)
     }
 
@@ -452,27 +452,27 @@ impl Element {
         0
     }
 
-    pub fn GetInnerHTML(&self) -> Fallible<DOMString> {
+    pub fn GetInnerHTML(&self) -> Fallible<Option<DOMString>> {
         Ok(None)
     }
 
-    pub fn SetInnerHTML(&mut self, _value: &DOMString) -> ErrorResult {
+    pub fn SetInnerHTML(&mut self, _value: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn GetOuterHTML(&self) -> Fallible<DOMString> {
+    pub fn GetOuterHTML(&self) -> Fallible<Option<DOMString>> {
         Ok(None)
     }
 
-    pub fn SetOuterHTML(&mut self, _value: &DOMString) -> ErrorResult {
+    pub fn SetOuterHTML(&mut self, _value: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn InsertAdjacentHTML(&mut self, _position: &DOMString, _text: &DOMString) -> ErrorResult {
+    pub fn InsertAdjacentHTML(&mut self, _position: &Option<DOMString>, _text: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn QuerySelector(&self, _selectors: &DOMString) -> Fallible<Option<AbstractNode<ScriptView>>> {
+    pub fn QuerySelector(&self, _selectors: &Option<DOMString>) -> Fallible<Option<AbstractNode<ScriptView>>> {
         Ok(None)
     }
 }
diff --git a/src/components/script/dom/event.rs b/src/components/script/dom/event.rs
index aa70ade8f5c..985c5bf7cf4 100644
--- a/src/components/script/dom/event.rs
+++ b/src/components/script/dom/event.rs
@@ -181,7 +181,7 @@ impl Event {
         self.phase as u16
     }
 
-    pub fn Type(&self) -> DOMString {
+    pub fn Type(&self) -> Option<DOMString> {
         Some(self.type_.clone())
     }
 
@@ -225,7 +225,7 @@ impl Event {
     }
 
     pub fn InitEvent(&mut self,
-                     type_: &DOMString,
+                     type_: &Option<DOMString>,
                      bubbles: bool,
                      cancelable: bool) -> ErrorResult {
         self.type_ = null_str_as_word_null(type_);
@@ -240,7 +240,7 @@ impl Event {
     }
 
     pub fn Constructor(global: @mut Window,
-                       type_: &DOMString,
+                       type_: &Option<DOMString>,
                        init: &EventBinding::EventInit) -> Fallible<AbstractEvent> {
         let ev = Event::new(global, HTMLEventTypeId);
         ev.mut_event().InitEvent(type_, init.bubbles, init.cancelable);
diff --git a/src/components/script/dom/eventtarget.rs b/src/components/script/dom/eventtarget.rs
index 77753fd3b5a..e584d544637 100644
--- a/src/components/script/dom/eventtarget.rs
+++ b/src/components/script/dom/eventtarget.rs
@@ -141,7 +141,7 @@ impl EventTarget {
     }
 
     pub fn AddEventListener(&mut self,
-                            ty: &DOMString,
+                            ty: &Option<DOMString>,
                             listener: Option<EventListener>,
                             capture: bool) {
         for &listener in listener.iter() {
@@ -158,7 +158,7 @@ impl EventTarget {
     }
 
     pub fn RemoveEventListener(&mut self,
-                               ty: &DOMString,
+                               ty: &Option<DOMString>,
                                listener: Option<EventListener>,
                                capture: bool) {
         for &listener in listener.iter() {
diff --git a/src/components/script/dom/formdata.rs b/src/components/script/dom/formdata.rs
index de34386bcac..1c95f2b7b3b 100644
--- a/src/components/script/dom/formdata.rs
+++ b/src/components/script/dom/formdata.rs
@@ -11,8 +11,8 @@ use dom::window::Window;
 use std::hashmap::HashMap;
 
 enum FormDatum {
-    StringData(DOMString),
-    BlobData { blob: @mut Blob, name: DOMString }
+    StringData(Option<DOMString>),
+    BlobData { blob: @mut Blob, name: Option<DOMString> }
 }
 
 pub struct FormData {
@@ -34,7 +34,7 @@ impl FormData {
         reflect_dom_object(@mut FormData::new_inherited(window), window, FormDataBinding::Wrap)
     }
 
-    pub fn Append(&mut self, name: &DOMString, value: @mut Blob, filename: Option<DOMString>) {
+    pub fn Append(&mut self, name: &Option<DOMString>, value: @mut Blob, filename: Option<Option<DOMString>>) {
         let blob = BlobData {
             blob: value,
             name: filename.unwrap_or(Some(~"default"))
@@ -42,7 +42,7 @@ impl FormData {
         self.data.insert(null_str_as_empty(name), blob);
     }
 
-    pub fn Append_(&mut self, name: &DOMString, value: &DOMString) {
+    pub fn Append_(&mut self, name: &Option<DOMString>, value: &Option<DOMString>) {
         self.data.insert(null_str_as_empty(name), StringData((*value).clone()));
     }
 }
diff --git a/src/components/script/dom/htmlanchorelement.rs b/src/components/script/dom/htmlanchorelement.rs
index 21a28aecaeb..4f11edbc288 100644
--- a/src/components/script/dom/htmlanchorelement.rs
+++ b/src/components/script/dom/htmlanchorelement.rs
@@ -27,107 +27,107 @@ impl HTMLAnchorElement {
 }
 
 impl HTMLAnchorElement {
-    pub fn Href(&self) -> DOMString {
+    pub fn Href(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetHref(&mut self, _href: &DOMString) -> ErrorResult {
+    pub fn SetHref(&mut self, _href: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Target(&self) -> DOMString {
+    pub fn Target(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetTarget(&self, _target: &DOMString) -> ErrorResult {
+    pub fn SetTarget(&self, _target: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Download(&self) -> DOMString {
+    pub fn Download(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetDownload(&self, _download: &DOMString) -> ErrorResult {
+    pub fn SetDownload(&self, _download: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Ping(&self) -> DOMString {
+    pub fn Ping(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetPing(&self, _ping: &DOMString) -> ErrorResult {
+    pub fn SetPing(&self, _ping: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Rel(&self) -> DOMString {
+    pub fn Rel(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetRel(&self, _rel: &DOMString) -> ErrorResult {
+    pub fn SetRel(&self, _rel: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Hreflang(&self) -> DOMString {
+    pub fn Hreflang(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetHreflang(&self, _href_lang: &DOMString) -> ErrorResult {
+    pub fn SetHreflang(&self, _href_lang: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Type(&self) -> DOMString {
+    pub fn Type(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetType(&mut self, _type: &DOMString) -> ErrorResult {
+    pub fn SetType(&mut self, _type: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Text(&self) -> DOMString {
+    pub fn Text(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetText(&mut self, _text: &DOMString) -> ErrorResult {
+    pub fn SetText(&mut self, _text: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Coords(&self) -> DOMString {
+    pub fn Coords(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetCoords(&mut self, _coords: &DOMString) -> ErrorResult {
+    pub fn SetCoords(&mut self, _coords: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Charset(&self) -> DOMString {
+    pub fn Charset(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetCharset(&mut self, _charset: &DOMString) -> ErrorResult {
+    pub fn SetCharset(&mut self, _charset: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Name(&self) -> DOMString {
+    pub fn Name(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetName(&mut self, _name: &DOMString) -> ErrorResult {
+    pub fn SetName(&mut self, _name: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Rev(&self) -> DOMString {
+    pub fn Rev(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetRev(&mut self, _rev: &DOMString) -> ErrorResult {
+    pub fn SetRev(&mut self, _rev: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Shape(&self) -> DOMString {
+    pub fn Shape(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetShape(&mut self, _shape: &DOMString) -> ErrorResult {
+    pub fn SetShape(&mut self, _shape: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlappletelement.rs b/src/components/script/dom/htmlappletelement.rs
index 7471c3557d6..e2be12ceb09 100644
--- a/src/components/script/dom/htmlappletelement.rs
+++ b/src/components/script/dom/htmlappletelement.rs
@@ -27,51 +27,51 @@ impl HTMLAppletElement {
 }
 
 impl HTMLAppletElement {
-    pub fn Align(&self) -> DOMString {
+    pub fn Align(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetAlign(&mut self, _align: &DOMString) -> ErrorResult {
+    pub fn SetAlign(&mut self, _align: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Alt(&self) -> DOMString {
+    pub fn Alt(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetAlt(&self, _alt: &DOMString) -> ErrorResult {
+    pub fn SetAlt(&self, _alt: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Archive(&self) -> DOMString {
+    pub fn Archive(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetArchive(&self, _archive: &DOMString) -> ErrorResult {
+    pub fn SetArchive(&self, _archive: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Code(&self) -> DOMString {
+    pub fn Code(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetCode(&self, _code: &DOMString) -> ErrorResult {
+    pub fn SetCode(&self, _code: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn CodeBase(&self) -> DOMString {
+    pub fn CodeBase(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetCodeBase(&self, _code_base: &DOMString) -> ErrorResult {
+    pub fn SetCodeBase(&self, _code_base: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Height(&self) -> DOMString {
+    pub fn Height(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetHeight(&self, _height: &DOMString) -> ErrorResult {
+    pub fn SetHeight(&self, _height: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
@@ -83,19 +83,19 @@ impl HTMLAppletElement {
         Ok(())
     }
 
-    pub fn Name(&self) -> DOMString {
+    pub fn Name(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetName(&mut self, _name: &DOMString) -> ErrorResult {
+    pub fn SetName(&mut self, _name: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Object(&self) -> DOMString {
+    pub fn Object(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetObject(&mut self, _object: &DOMString) -> ErrorResult {
+    pub fn SetObject(&mut self, _object: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
@@ -107,11 +107,11 @@ impl HTMLAppletElement {
         Ok(())
     }
 
-    pub fn Width(&self) -> DOMString {
+    pub fn Width(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetWidth(&mut self, _width: &DOMString) -> ErrorResult {
+    pub fn SetWidth(&mut self, _width: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlareaelement.rs b/src/components/script/dom/htmlareaelement.rs
index 4f77f9a12ed..2a005020c2c 100644
--- a/src/components/script/dom/htmlareaelement.rs
+++ b/src/components/script/dom/htmlareaelement.rs
@@ -27,59 +27,59 @@ impl HTMLAreaElement {
 }
 
 impl HTMLAreaElement {
-    pub fn Alt(&self) -> DOMString {
+    pub fn Alt(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetAlt(&self, _alt: &DOMString) -> ErrorResult {
+    pub fn SetAlt(&self, _alt: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Coords(&self) -> DOMString {
+    pub fn Coords(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetCoords(&self, _coords: &DOMString) -> ErrorResult {
+    pub fn SetCoords(&self, _coords: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Shape(&self) -> DOMString {
+    pub fn Shape(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetShape(&self, _shape: &DOMString) -> ErrorResult {
+    pub fn SetShape(&self, _shape: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Href(&self) -> DOMString {
+    pub fn Href(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetHref(&self, _href: &DOMString) -> ErrorResult {
+    pub fn SetHref(&self, _href: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Target(&self) -> DOMString {
+    pub fn Target(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetTarget(&self, _target: &DOMString) -> ErrorResult {
+    pub fn SetTarget(&self, _target: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Download(&self) -> DOMString {
+    pub fn Download(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetDownload(&self, _download: &DOMString) -> ErrorResult {
+    pub fn SetDownload(&self, _download: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Ping(&self) -> DOMString {
+    pub fn Ping(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetPing(&self, _ping: &DOMString) -> ErrorResult {
+    pub fn SetPing(&self, _ping: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
diff --git a/src/components/script/dom/htmlbaseelement.rs b/src/components/script/dom/htmlbaseelement.rs
index 077db6d8405..47b61ebbd86 100644
--- a/src/components/script/dom/htmlbaseelement.rs
+++ b/src/components/script/dom/htmlbaseelement.rs
@@ -27,19 +27,19 @@ impl HTMLBaseElement {
 }
 
 impl HTMLBaseElement {
-    pub fn Href(&self) -> DOMString {
+    pub fn Href(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetHref(&self, _href: &DOMString) -> ErrorResult {
+    pub fn SetHref(&self, _href: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Target(&self) -> DOMString {
+    pub fn Target(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetTarget(&self, _target: &DOMString) -> ErrorResult {
+    pub fn SetTarget(&self, _target: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlbodyelement.rs b/src/components/script/dom/htmlbodyelement.rs
index 4105c0742ad..1c812c0652f 100644
--- a/src/components/script/dom/htmlbodyelement.rs
+++ b/src/components/script/dom/htmlbodyelement.rs
@@ -27,51 +27,51 @@ impl HTMLBodyElement {
 }
 
 impl HTMLBodyElement {
-    pub fn Text(&self) -> DOMString {
+    pub fn Text(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetText(&mut self, _text: &DOMString) -> ErrorResult {
+    pub fn SetText(&mut self, _text: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Link(&self) -> DOMString {
+    pub fn Link(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetLink(&self, _link: &DOMString) -> ErrorResult {
+    pub fn SetLink(&self, _link: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn VLink(&self) -> DOMString {
+    pub fn VLink(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetVLink(&self, _v_link: &DOMString) -> ErrorResult {
+    pub fn SetVLink(&self, _v_link: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn ALink(&self) -> DOMString {
+    pub fn ALink(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetALink(&self, _a_link: &DOMString) -> ErrorResult {
+    pub fn SetALink(&self, _a_link: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn BgColor(&self) -> DOMString {
+    pub fn BgColor(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetBgColor(&self, _bg_color: &DOMString) -> ErrorResult {
+    pub fn SetBgColor(&self, _bg_color: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Background(&self) -> DOMString {
+    pub fn Background(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetBackground(&self, _background: &DOMString) -> ErrorResult {
+    pub fn SetBackground(&self, _background: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlbrelement.rs b/src/components/script/dom/htmlbrelement.rs
index 653424c1c8c..b216171394c 100644
--- a/src/components/script/dom/htmlbrelement.rs
+++ b/src/components/script/dom/htmlbrelement.rs
@@ -27,11 +27,11 @@ impl HTMLBRElement {
 }
 
 impl HTMLBRElement {
-    pub fn Clear(&self) -> DOMString {
+    pub fn Clear(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetClear(&mut self, _text: &DOMString) -> ErrorResult {
+    pub fn SetClear(&mut self, _text: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlbuttonelement.rs b/src/components/script/dom/htmlbuttonelement.rs
index 5bd1c352d8e..fbf81b5f0dd 100644
--- a/src/components/script/dom/htmlbuttonelement.rs
+++ b/src/components/script/dom/htmlbuttonelement.rs
@@ -48,27 +48,27 @@ impl HTMLButtonElement {
         None
     }
 
-    pub fn FormAction(&self) -> DOMString {
+    pub fn FormAction(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetFormAction(&mut self, _formaction: &DOMString) -> ErrorResult {
+    pub fn SetFormAction(&mut self, _formaction: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn FormEnctype(&self) -> DOMString {
+    pub fn FormEnctype(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetFormEnctype(&mut self, _formenctype: &DOMString) -> ErrorResult {
+    pub fn SetFormEnctype(&mut self, _formenctype: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn FormMethod(&self) -> DOMString {
+    pub fn FormMethod(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetFormMethod(&mut self, _formmethod: &DOMString) -> ErrorResult {
+    pub fn SetFormMethod(&mut self, _formmethod: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
@@ -80,35 +80,35 @@ impl HTMLButtonElement {
         Ok(())
     }
 
-    pub fn FormTarget(&self) -> DOMString {
+    pub fn FormTarget(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetFormTarget(&mut self, _formtarget: &DOMString) -> ErrorResult {
+    pub fn SetFormTarget(&mut self, _formtarget: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Name(&self) -> DOMString {
+    pub fn Name(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetName(&mut self, _name: &DOMString) -> ErrorResult {
+    pub fn SetName(&mut self, _name: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
     
-    pub fn Type(&self) -> DOMString {
+    pub fn Type(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetType(&mut self, _type: &DOMString) -> ErrorResult {
+    pub fn SetType(&mut self, _type: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Value(&self) -> DOMString {
+    pub fn Value(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetValue(&mut self, _value: &DOMString) -> ErrorResult {
+    pub fn SetValue(&mut self, _value: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
@@ -127,11 +127,11 @@ impl HTMLButtonElement {
     pub fn SetValidity(&mut self, _validity: @mut ValidityState) {
     }
 
-    pub fn ValidationMessage(&self) -> DOMString {
+    pub fn ValidationMessage(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetValidationMessage(&mut self, _message: &DOMString) -> ErrorResult {
+    pub fn SetValidationMessage(&mut self, _message: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
@@ -139,6 +139,6 @@ impl HTMLButtonElement {
         true
     }
 
-    pub fn SetCustomValidity(&mut self, _error: &DOMString) {
+    pub fn SetCustomValidity(&mut self, _error: &Option<DOMString>) {
     }
 }
diff --git a/src/components/script/dom/htmlcollection.rs b/src/components/script/dom/htmlcollection.rs
index 03a5ebac878..b42277d72ad 100644
--- a/src/components/script/dom/htmlcollection.rs
+++ b/src/components/script/dom/htmlcollection.rs
@@ -46,7 +46,7 @@ impl HTMLCollection {
         }
     }
 
-    pub fn NamedItem(&self, _cx: *JSContext, _name: &DOMString) -> Fallible<*JSObject> {
+    pub fn NamedItem(&self, _cx: *JSContext, _name: &Option<DOMString>) -> Fallible<*JSObject> {
         Ok(ptr::null())
     }
 
@@ -55,7 +55,7 @@ impl HTMLCollection {
         self.Item(index)
     }
 
-    pub fn NamedGetter(&self, _cx: *JSContext, _name: &DOMString, _found: &mut bool) -> Fallible<*JSObject> {
+    pub fn NamedGetter(&self, _cx: *JSContext, _name: &Option<DOMString>, _found: &mut bool) -> Fallible<*JSObject> {
         Ok(ptr::null())
     }
 }
diff --git a/src/components/script/dom/htmldataelement.rs b/src/components/script/dom/htmldataelement.rs
index 5e97f113cbf..7c367f9f300 100644
--- a/src/components/script/dom/htmldataelement.rs
+++ b/src/components/script/dom/htmldataelement.rs
@@ -27,11 +27,11 @@ impl HTMLDataElement {
 }
 
 impl HTMLDataElement {
-    pub fn Value(&self) -> DOMString {
+    pub fn Value(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetValue(&mut self, _value: &DOMString) -> ErrorResult {
+    pub fn SetValue(&mut self, _value: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 }
diff --git a/src/components/script/dom/htmldivelement.rs b/src/components/script/dom/htmldivelement.rs
index 26ce3ba6a14..11d56dd1eda 100644
--- a/src/components/script/dom/htmldivelement.rs
+++ b/src/components/script/dom/htmldivelement.rs
@@ -27,11 +27,11 @@ impl HTMLDivElement {
 }
 
 impl HTMLDivElement {
-    pub fn Align(&self) -> DOMString {
+    pub fn Align(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetAlign(&mut self, _align: &DOMString) -> ErrorResult {
+    pub fn SetAlign(&mut self, _align: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 }
diff --git a/src/components/script/dom/htmldlistelement.rs b/src/components/script/dom/htmldlistelement.rs
index 63b770e9534..96647e53794 100644
--- a/src/components/script/dom/htmldlistelement.rs
+++ b/src/components/script/dom/htmldlistelement.rs
@@ -35,11 +35,11 @@ impl HTMLDListElement {
         Ok(())
     }
 
-    pub fn Type(&self) -> DOMString {
+    pub fn Type(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetType(&mut self, _type: &DOMString) -> ErrorResult {
+    pub fn SetType(&mut self, _type: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlelement.rs b/src/components/script/dom/htmlelement.rs
index b7ff82b6e6d..e157a79f520 100644
--- a/src/components/script/dom/htmlelement.rs
+++ b/src/components/script/dom/htmlelement.rs
@@ -28,25 +28,25 @@ impl HTMLElement {
 }
 
 impl HTMLElement {
-    pub fn Title(&self) -> DOMString {
+    pub fn Title(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetTitle(&mut self, _title: &DOMString) {
+    pub fn SetTitle(&mut self, _title: &Option<DOMString>) {
     }
 
-    pub fn Lang(&self) -> DOMString {
+    pub fn Lang(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetLang(&mut self, _lang: &DOMString) {
+    pub fn SetLang(&mut self, _lang: &Option<DOMString>) {
     }
 
-    pub fn Dir(&self) -> DOMString {
+    pub fn Dir(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetDir(&mut self, _dir: &DOMString) -> ErrorResult {
+    pub fn SetDir(&mut self, _dir: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
@@ -85,15 +85,15 @@ impl HTMLElement {
         Ok(())
     }
 
-    pub fn AccessKey(&self) -> DOMString {
+    pub fn AccessKey(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetAccessKey(&self, _key: &DOMString) -> ErrorResult {
+    pub fn SetAccessKey(&self, _key: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn AccessKeyLabel(&self) -> DOMString {
+    pub fn AccessKeyLabel(&self) -> Option<DOMString> {
         None
     }
 
@@ -105,11 +105,11 @@ impl HTMLElement {
         Ok(())
     }
 
-    pub fn ContentEditable(&self) -> DOMString {
+    pub fn ContentEditable(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetContentEditable(&mut self, _val: &DOMString) -> ErrorResult {
+    pub fn SetContentEditable(&mut self, _val: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
@@ -125,11 +125,11 @@ impl HTMLElement {
         Ok(())
     }
 
-    pub fn ClassName(&self) -> DOMString {
+    pub fn ClassName(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetClassName(&self, _class: &DOMString) {
+    pub fn SetClassName(&self, _class: &Option<DOMString>) {
     }
 
     pub fn GetOffsetParent(&self) -> Option<AbstractNode<ScriptView>> {
diff --git a/src/components/script/dom/htmlembedelement.rs b/src/components/script/dom/htmlembedelement.rs
index ca9b0e5a53e..e1e6151918c 100644
--- a/src/components/script/dom/htmlembedelement.rs
+++ b/src/components/script/dom/htmlembedelement.rs
@@ -27,51 +27,51 @@ impl HTMLEmbedElement {
 }
 
 impl HTMLEmbedElement {
-    pub fn Src(&self) -> DOMString {
+    pub fn Src(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetSrc(&mut self, _src: &DOMString) -> ErrorResult {
+    pub fn SetSrc(&mut self, _src: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Type(&self) -> DOMString {
+    pub fn Type(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetType(&mut self, _type: &DOMString) -> ErrorResult {
+    pub fn SetType(&mut self, _type: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Width(&self) -> DOMString {
+    pub fn Width(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetWidth(&mut self, _width: &DOMString) -> ErrorResult {
+    pub fn SetWidth(&mut self, _width: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Height(&self) -> DOMString {
+    pub fn Height(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetHeight(&mut self, _height: &DOMString) -> ErrorResult {
+    pub fn SetHeight(&mut self, _height: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Align(&self) -> DOMString {
+    pub fn Align(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetAlign(&mut self, _type: &DOMString) -> ErrorResult {
+    pub fn SetAlign(&mut self, _type: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Name(&self) -> DOMString {
+    pub fn Name(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetName(&mut self, _type: &DOMString) -> ErrorResult {
+    pub fn SetName(&mut self, _type: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
diff --git a/src/components/script/dom/htmlfieldsetelement.rs b/src/components/script/dom/htmlfieldsetelement.rs
index 89011d9dfda..5c87ea51f47 100644
--- a/src/components/script/dom/htmlfieldsetelement.rs
+++ b/src/components/script/dom/htmlfieldsetelement.rs
@@ -41,15 +41,15 @@ impl HTMLFieldSetElement {
         None
     }
 
-    pub fn Name(&self) -> DOMString {
+    pub fn Name(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetName(&mut self, _name: &DOMString) -> ErrorResult {
+    pub fn SetName(&mut self, _name: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Type(&self) -> DOMString {
+    pub fn Type(&self) -> Option<DOMString> {
         None
     }
 
@@ -67,7 +67,7 @@ impl HTMLFieldSetElement {
         ValidityState::new(global)
     }
 
-    pub fn ValidationMessage(&self) -> DOMString {
+    pub fn ValidationMessage(&self) -> Option<DOMString> {
         None
     }
 
@@ -75,6 +75,6 @@ impl HTMLFieldSetElement {
         false
     }
 
-    pub fn SetCustomValidity(&mut self, _error: &DOMString) {
+    pub fn SetCustomValidity(&mut self, _error: &Option<DOMString>) {
     }
 }
diff --git a/src/components/script/dom/htmlfontelement.rs b/src/components/script/dom/htmlfontelement.rs
index d15251e4c7d..6ddf3491dbf 100644
--- a/src/components/script/dom/htmlfontelement.rs
+++ b/src/components/script/dom/htmlfontelement.rs
@@ -27,27 +27,27 @@ impl HTMLFontElement {
 }
 
 impl HTMLFontElement {
-    pub fn Color(&self) -> DOMString {
+    pub fn Color(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetColor(&mut self, _color: &DOMString) -> ErrorResult {
+    pub fn SetColor(&mut self, _color: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Face(&self) -> DOMString {
+    pub fn Face(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetFace(&mut self, _face: &DOMString) -> ErrorResult {
+    pub fn SetFace(&mut self, _face: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
     
-    pub fn Size(&self) -> DOMString {
+    pub fn Size(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetSize(&mut self, _size: &DOMString) -> ErrorResult {
+    pub fn SetSize(&mut self, _size: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlformelement.rs b/src/components/script/dom/htmlformelement.rs
index 54469a9631f..5d81fabd0d0 100644
--- a/src/components/script/dom/htmlformelement.rs
+++ b/src/components/script/dom/htmlformelement.rs
@@ -28,59 +28,59 @@ impl HTMLFormElement {
 }
 
 impl HTMLFormElement {
-    pub fn AcceptCharset(&self) -> DOMString {
+    pub fn AcceptCharset(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetAcceptCharset(&mut self, _accept_charset: &DOMString) -> ErrorResult {
+    pub fn SetAcceptCharset(&mut self, _accept_charset: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Action(&self) -> DOMString {
+    pub fn Action(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetAction(&mut self, _action: &DOMString) -> ErrorResult {
+    pub fn SetAction(&mut self, _action: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Autocomplete(&self) -> DOMString {
+    pub fn Autocomplete(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetAutocomplete(&mut self, _autocomplete: &DOMString) -> ErrorResult {
+    pub fn SetAutocomplete(&mut self, _autocomplete: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Enctype(&self) -> DOMString {
+    pub fn Enctype(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetEnctype(&mut self, _enctype: &DOMString) -> ErrorResult {
+    pub fn SetEnctype(&mut self, _enctype: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Encoding(&self) -> DOMString {
+    pub fn Encoding(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetEncoding(&mut self, _encoding: &DOMString) -> ErrorResult {
+    pub fn SetEncoding(&mut self, _encoding: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Method(&self) -> DOMString {
+    pub fn Method(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetMethod(&mut self, _method: &DOMString) -> ErrorResult {
+    pub fn SetMethod(&mut self, _method: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Name(&self) -> DOMString {
+    pub fn Name(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetName(&mut self, _name: &DOMString) -> ErrorResult {
+    pub fn SetName(&mut self, _name: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
@@ -92,11 +92,11 @@ impl HTMLFormElement {
         Ok(())
     }
 
-    pub fn Target(&self) -> DOMString {
+    pub fn Target(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetTarget(&mut self, _target: &DOMString) -> ErrorResult {
+    pub fn SetTarget(&mut self, _target: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
diff --git a/src/components/script/dom/htmlframeelement.rs b/src/components/script/dom/htmlframeelement.rs
index a9ab387c58e..7a688fa4cc6 100644
--- a/src/components/script/dom/htmlframeelement.rs
+++ b/src/components/script/dom/htmlframeelement.rs
@@ -28,43 +28,43 @@ impl HTMLFrameElement {
 }
 
 impl HTMLFrameElement {
-    pub fn Name(&self) -> DOMString {
+    pub fn Name(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetName(&mut self, _name: &DOMString) -> ErrorResult {
+    pub fn SetName(&mut self, _name: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Scrolling(&self) -> DOMString {
+    pub fn Scrolling(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetScrolling(&mut self, _scrolling: &DOMString) -> ErrorResult {
+    pub fn SetScrolling(&mut self, _scrolling: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Src(&self) -> DOMString {
+    pub fn Src(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetSrc(&mut self, _src: &DOMString) -> ErrorResult {
+    pub fn SetSrc(&mut self, _src: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn FrameBorder(&self) -> DOMString {
+    pub fn FrameBorder(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetFrameBorder(&mut self, _frameborder: &DOMString) -> ErrorResult {
+    pub fn SetFrameBorder(&mut self, _frameborder: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn LongDesc(&self) -> DOMString {
+    pub fn LongDesc(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetLongDesc(&mut self, _longdesc: &DOMString) -> ErrorResult {
+    pub fn SetLongDesc(&mut self, _longdesc: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
@@ -84,19 +84,19 @@ impl HTMLFrameElement {
         None
     }
 
-    pub fn MarginHeight(&self) -> DOMString {
+    pub fn MarginHeight(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetMarginHeight(&mut self, _height: &DOMString) -> ErrorResult {
+    pub fn SetMarginHeight(&mut self, _height: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn MarginWidth(&self) -> DOMString {
+    pub fn MarginWidth(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetMarginWidth(&mut self, _height: &DOMString) -> ErrorResult {
+    pub fn SetMarginWidth(&mut self, _height: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlframesetelement.rs b/src/components/script/dom/htmlframesetelement.rs
index 42dc12f78e4..56490e9ca2a 100644
--- a/src/components/script/dom/htmlframesetelement.rs
+++ b/src/components/script/dom/htmlframesetelement.rs
@@ -27,19 +27,19 @@ impl HTMLFrameSetElement {
 }
 
 impl HTMLFrameSetElement {
-    pub fn Cols(&self) -> DOMString {
+    pub fn Cols(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetCols(&mut self, _cols: &DOMString) -> ErrorResult {
+    pub fn SetCols(&mut self, _cols: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Rows(&self) -> DOMString {
+    pub fn Rows(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetRows(&mut self, _rows: &DOMString) -> ErrorResult {
+    pub fn SetRows(&mut self, _rows: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlheadingelement.rs b/src/components/script/dom/htmlheadingelement.rs
index a8b840b6edc..2e5c4db10a2 100644
--- a/src/components/script/dom/htmlheadingelement.rs
+++ b/src/components/script/dom/htmlheadingelement.rs
@@ -38,10 +38,10 @@ impl HTMLHeadingElement {
 }
 
 impl HTMLHeadingElement {
-    pub fn Align(&self) -> DOMString {
+    pub fn Align(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetAlign(&mut self, _align: &DOMString) {
+    pub fn SetAlign(&mut self, _align: &Option<DOMString>) {
     }
 }
diff --git a/src/components/script/dom/htmlhrelement.rs b/src/components/script/dom/htmlhrelement.rs
index cb7662148c1..222cc397a24 100644
--- a/src/components/script/dom/htmlhrelement.rs
+++ b/src/components/script/dom/htmlhrelement.rs
@@ -27,19 +27,19 @@ impl HTMLHRElement {
 }
 
 impl HTMLHRElement {
-    pub fn Align(&self) -> DOMString {
+    pub fn Align(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetAlign(&mut self, _align: &DOMString) -> ErrorResult {
+    pub fn SetAlign(&mut self, _align: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Color(&self) -> DOMString {
+    pub fn Color(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetColor(&mut self, _color: &DOMString) -> ErrorResult {
+    pub fn SetColor(&mut self, _color: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
@@ -51,19 +51,19 @@ impl HTMLHRElement {
         Ok(())
     }
 
-    pub fn Size(&self) -> DOMString {
+    pub fn Size(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetSize(&mut self, _size: &DOMString) -> ErrorResult {
+    pub fn SetSize(&mut self, _size: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Width(&self) -> DOMString {
+    pub fn Width(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetWidth(&mut self, _width: &DOMString) -> ErrorResult {
+    pub fn SetWidth(&mut self, _width: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlhtmlelement.rs b/src/components/script/dom/htmlhtmlelement.rs
index 1292ff49692..1a14961fab6 100644
--- a/src/components/script/dom/htmlhtmlelement.rs
+++ b/src/components/script/dom/htmlhtmlelement.rs
@@ -27,11 +27,11 @@ impl HTMLHtmlElement {
 }
 
 impl HTMLHtmlElement {
-    pub fn Version(&self) -> DOMString {
+    pub fn Version(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetVersion(&mut self, _version: &DOMString) -> ErrorResult {
+    pub fn SetVersion(&mut self, _version: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 }
diff --git a/src/components/script/dom/htmliframeelement.rs b/src/components/script/dom/htmliframeelement.rs
index 08bde32f44e..f93d28b61ae 100644
--- a/src/components/script/dom/htmliframeelement.rs
+++ b/src/components/script/dom/htmliframeelement.rs
@@ -77,39 +77,39 @@ impl HTMLIFrameElement {
 }
 
 impl HTMLIFrameElement {
-    pub fn Src(&self) -> DOMString {
+    pub fn Src(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetSrc(&mut self, _src: &DOMString) -> ErrorResult {
+    pub fn SetSrc(&mut self, _src: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Srcdoc(&self) -> DOMString {
+    pub fn Srcdoc(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetSrcdoc(&mut self, _srcdoc: &DOMString) -> ErrorResult {
+    pub fn SetSrcdoc(&mut self, _srcdoc: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Name(&self) -> DOMString {
+    pub fn Name(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetName(&mut self, _name: &DOMString) -> ErrorResult {
+    pub fn SetName(&mut self, _name: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Sandbox(&self, _abstract_self: AbstractNode<ScriptView>) -> DOMString {
+    pub fn Sandbox(&self, _abstract_self: AbstractNode<ScriptView>) -> Option<DOMString> {
         self.htmlelement.element.GetAttribute(&Some(~"sandbox"))
     }
 
-    pub fn SetSandbox(&mut self, abstract_self: AbstractNode<ScriptView>, sandbox: &DOMString) {
+    pub fn SetSandbox(&mut self, abstract_self: AbstractNode<ScriptView>, sandbox: &Option<DOMString>) {
         self.htmlelement.element.SetAttribute(abstract_self, &Some(~"sandbox"), sandbox);
     }
 
-    pub fn AfterSetAttr(&mut self, name: &DOMString, value: &DOMString) {
+    pub fn AfterSetAttr(&mut self, name: &Option<DOMString>, value: &Option<DOMString>) {
         let name = null_str_as_empty(name);
         if "sandbox" == name {
             let mut modes = AllowNothing as u8;
@@ -137,19 +137,19 @@ impl HTMLIFrameElement {
         Ok(())
     }
 
-    pub fn Width(&self) -> DOMString {
+    pub fn Width(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetWidth(&mut self, _width: &DOMString) -> ErrorResult {
+    pub fn SetWidth(&mut self, _width: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Height(&self) -> DOMString {
+    pub fn Height(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetHeight(&mut self, _height: &DOMString) -> ErrorResult {
+    pub fn SetHeight(&mut self, _height: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
@@ -161,51 +161,51 @@ impl HTMLIFrameElement {
         None
     }
 
-    pub fn Align(&self) -> DOMString {
+    pub fn Align(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetAlign(&mut self, _align: &DOMString) -> ErrorResult {
+    pub fn SetAlign(&mut self, _align: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Scrolling(&self) -> DOMString {
+    pub fn Scrolling(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetScrolling(&mut self, _scrolling: &DOMString) -> ErrorResult {
+    pub fn SetScrolling(&mut self, _scrolling: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn FrameBorder(&self) -> DOMString {
+    pub fn FrameBorder(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetFrameBorder(&mut self, _frameborder: &DOMString) -> ErrorResult {
+    pub fn SetFrameBorder(&mut self, _frameborder: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn LongDesc(&self) -> DOMString {
+    pub fn LongDesc(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetLongDesc(&mut self, _longdesc: &DOMString) -> ErrorResult {
+    pub fn SetLongDesc(&mut self, _longdesc: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn MarginHeight(&self) -> DOMString {
+    pub fn MarginHeight(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetMarginHeight(&mut self, _marginheight: &DOMString) -> ErrorResult {
+    pub fn SetMarginHeight(&mut self, _marginheight: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn MarginWidth(&self) -> DOMString {
+    pub fn MarginWidth(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetMarginWidth(&mut self, _marginwidth: &DOMString) -> ErrorResult {
+    pub fn SetMarginWidth(&mut self, _marginwidth: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
diff --git a/src/components/script/dom/htmlimageelement.rs b/src/components/script/dom/htmlimageelement.rs
index 94b48b6252f..0f34f1a52f2 100644
--- a/src/components/script/dom/htmlimageelement.rs
+++ b/src/components/script/dom/htmlimageelement.rs
@@ -57,7 +57,7 @@ impl HTMLImageElement {
         }
     }
 
-    pub fn AfterSetAttr(&mut self, name: &DOMString, _value: &DOMString) {
+    pub fn AfterSetAttr(&mut self, name: &Option<DOMString>, _value: &Option<DOMString>) {
         let name = null_str_as_empty(name);
         if "src" == name {
             let document = self.htmlelement.element.node.owner_doc();
@@ -67,21 +67,21 @@ impl HTMLImageElement {
         }
     }
 
-    pub fn Alt(&self) -> DOMString {
+    pub fn Alt(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetAlt(&mut self, _alt: &DOMString) -> ErrorResult {
+    pub fn SetAlt(&mut self, _alt: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Src(&self, _abstract_self: AbstractNode<ScriptView>) -> DOMString {
+    pub fn Src(&self, _abstract_self: AbstractNode<ScriptView>) -> Option<DOMString> {
         None
     }
 
     pub fn SetSrc(&mut self,
                   abstract_self: AbstractNode<ScriptView>,
-                  src: &DOMString) -> ErrorResult {
+                  src: &Option<DOMString>) -> ErrorResult {
         let node = &mut self.htmlelement.element;
         node.set_attr(abstract_self,
                       &Some(~"src"),
@@ -89,19 +89,19 @@ impl HTMLImageElement {
         Ok(())
     }
 
-    pub fn CrossOrigin(&self) -> DOMString {
+    pub fn CrossOrigin(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetCrossOrigin(&mut self, _cross_origin: &DOMString) -> ErrorResult {
+    pub fn SetCrossOrigin(&mut self, _cross_origin: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn UseMap(&self) -> DOMString {
+    pub fn UseMap(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetUseMap(&mut self, _use_map: &DOMString) -> ErrorResult {
+    pub fn SetUseMap(&mut self, _use_map: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
@@ -167,19 +167,19 @@ impl HTMLImageElement {
         false
     }
 
-    pub fn Name(&self) -> DOMString {
+    pub fn Name(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetName(&mut self, _name: &DOMString) -> ErrorResult {
+    pub fn SetName(&mut self, _name: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Align(&self) -> DOMString {
+    pub fn Align(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetAlign(&mut self, _align: &DOMString) -> ErrorResult {
+    pub fn SetAlign(&mut self, _align: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
@@ -199,19 +199,19 @@ impl HTMLImageElement {
         Ok(())
     }
 
-    pub fn LongDesc(&self) -> DOMString {
+    pub fn LongDesc(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetLongDesc(&mut self, _longdesc: &DOMString) -> ErrorResult {
+    pub fn SetLongDesc(&mut self, _longdesc: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Border(&self) -> DOMString {
+    pub fn Border(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetBorder(&mut self, _border: &DOMString) -> ErrorResult {
+    pub fn SetBorder(&mut self, _border: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlinputelement.rs b/src/components/script/dom/htmlinputelement.rs
index 5e85f32dc79..b6b4c7786c6 100644
--- a/src/components/script/dom/htmlinputelement.rs
+++ b/src/components/script/dom/htmlinputelement.rs
@@ -27,27 +27,27 @@ impl HTMLInputElement {
 }
 
 impl HTMLInputElement {
-    pub fn Accept(&self) -> DOMString {
+    pub fn Accept(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetAccept(&mut self, _accept: &DOMString) -> ErrorResult {
+    pub fn SetAccept(&mut self, _accept: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Alt(&self) -> DOMString {
+    pub fn Alt(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetAlt(&mut self, _alt: &DOMString) -> ErrorResult {
+    pub fn SetAlt(&mut self, _alt: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Autocomplete(&self) -> DOMString {
+    pub fn Autocomplete(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetAutocomplete(&mut self, _autocomple: &DOMString) -> ErrorResult {
+    pub fn SetAutocomplete(&mut self, _autocomple: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
@@ -82,27 +82,27 @@ impl HTMLInputElement {
         Ok(())
     }
 
-    pub fn FormAction(&self) -> DOMString {
+    pub fn FormAction(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetFormAction(&mut self, _form_action: &DOMString) -> ErrorResult {
+    pub fn SetFormAction(&mut self, _form_action: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn FormEnctype(&self) -> DOMString {
+    pub fn FormEnctype(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetFormEnctype(&mut self, _form_enctype: &DOMString) -> ErrorResult {
+    pub fn SetFormEnctype(&mut self, _form_enctype: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn FormMethod(&self) -> DOMString {
+    pub fn FormMethod(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetFormMethod(&mut self, _form_method: &DOMString) -> ErrorResult {
+    pub fn SetFormMethod(&mut self, _form_method: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
@@ -114,11 +114,11 @@ impl HTMLInputElement {
         Ok(())
     }
 
-    pub fn FormTarget(&self) -> DOMString {
+    pub fn FormTarget(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetFormTarget(&mut self, _form_target: &DOMString) -> ErrorResult {
+    pub fn SetFormTarget(&mut self, _form_target: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
@@ -137,19 +137,19 @@ impl HTMLInputElement {
     pub fn SetIndeterminate(&mut self, _indeterminate: bool) {
     }
 
-    pub fn InputMode(&self) -> DOMString {
+    pub fn InputMode(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetInputMode(&mut self, _input_mode: &DOMString) -> ErrorResult {
+    pub fn SetInputMode(&mut self, _input_mode: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Max(&self) -> DOMString {
+    pub fn Max(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetMax(&mut self, _max: &DOMString) -> ErrorResult {
+    pub fn SetMax(&mut self, _max: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
@@ -161,11 +161,11 @@ impl HTMLInputElement {
         Ok(())
     }
 
-    pub fn Min(&self) -> DOMString {
+    pub fn Min(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetMin(&mut self, _min: &DOMString) -> ErrorResult {
+    pub fn SetMin(&mut self, _min: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
@@ -177,27 +177,27 @@ impl HTMLInputElement {
         Ok(())
     }
 
-    pub fn Name(&self) -> DOMString {
+    pub fn Name(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetName(&mut self, _name: &DOMString) -> ErrorResult {
+    pub fn SetName(&mut self, _name: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Pattern(&self) -> DOMString {
+    pub fn Pattern(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetPattern(&mut self, _pattern: &DOMString) -> ErrorResult {
+    pub fn SetPattern(&mut self, _pattern: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Placeholder(&self) -> DOMString {
+    pub fn Placeholder(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetPlaceholder(&mut self, _placeholder: &DOMString) -> ErrorResult {
+    pub fn SetPlaceholder(&mut self, _placeholder: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
@@ -225,43 +225,43 @@ impl HTMLInputElement {
         Ok(())
     }
 
-    pub fn Src(&self) -> DOMString {
+    pub fn Src(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetSrc(&mut self, _src: &DOMString) -> ErrorResult {
+    pub fn SetSrc(&mut self, _src: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Step(&self) -> DOMString {
+    pub fn Step(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetStep(&mut self, _step: &DOMString) -> ErrorResult {
+    pub fn SetStep(&mut self, _step: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Type(&self) -> DOMString {
+    pub fn Type(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetType(&mut self, _type: &DOMString) -> ErrorResult {
+    pub fn SetType(&mut self, _type: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn DefaultValue(&self) -> DOMString {
+    pub fn DefaultValue(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetDefaultValue(&mut self, _default_value: &DOMString) -> ErrorResult {
+    pub fn SetDefaultValue(&mut self, _default_value: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Value(&self) -> DOMString {
+    pub fn Value(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetValue(&mut self, _value: &DOMString) -> ErrorResult {
+    pub fn SetValue(&mut self, _value: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
@@ -279,7 +279,7 @@ impl HTMLInputElement {
     pub fn SetWillValidate(&self, _will_validate: bool) {
     }
 
-    pub fn GetValidationMessage(&self) -> Fallible<DOMString> {
+    pub fn GetValidationMessage(&self) -> Fallible<Option<DOMString>> {
         Ok(None)
     }
 
@@ -287,7 +287,7 @@ impl HTMLInputElement {
         false
     }
 
-    pub fn SetCustomValidity(&self, _error: &DOMString) {
+    pub fn SetCustomValidity(&self, _error: &Option<DOMString>) {
     }
 
     pub fn Select(&self) {
@@ -309,27 +309,27 @@ impl HTMLInputElement {
         Ok(())
     }
 
-    pub fn GetSelectionDirection(&self) -> Fallible<DOMString> {
+    pub fn GetSelectionDirection(&self) -> Fallible<Option<DOMString>> {
         Ok(None)
     }
 
-    pub fn SetSelectionDirection(&mut self, _selection_direction: &DOMString) -> ErrorResult {
+    pub fn SetSelectionDirection(&mut self, _selection_direction: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Align(&self) -> DOMString {
+    pub fn Align(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetAlign(&mut self, _align: &DOMString) -> ErrorResult {
+    pub fn SetAlign(&mut self, _align: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn UseMap(&self) -> DOMString {
+    pub fn UseMap(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetUseMap(&mut self, _align: &DOMString) -> ErrorResult {
+    pub fn SetUseMap(&mut self, _align: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 }
diff --git a/src/components/script/dom/htmllabelelement.rs b/src/components/script/dom/htmllabelelement.rs
index 35ffbfa900e..9d59f687397 100644
--- a/src/components/script/dom/htmllabelelement.rs
+++ b/src/components/script/dom/htmllabelelement.rs
@@ -27,10 +27,10 @@ impl HTMLLabelElement {
 }
 
 impl HTMLLabelElement {
-    pub fn HtmlFor(&self) -> DOMString {
+    pub fn HtmlFor(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetHtmlFor(&mut self, _html_for: &DOMString) {
+    pub fn SetHtmlFor(&mut self, _html_for: &Option<DOMString>) {
     }
 }
diff --git a/src/components/script/dom/htmllegendelement.rs b/src/components/script/dom/htmllegendelement.rs
index 2eeec359a44..4ed9d385cba 100644
--- a/src/components/script/dom/htmllegendelement.rs
+++ b/src/components/script/dom/htmllegendelement.rs
@@ -27,11 +27,11 @@ impl HTMLLegendElement {
 }
 
 impl HTMLLegendElement {
-    pub fn Align(&self) -> DOMString {
+    pub fn Align(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetAlign(&mut self, _align: &DOMString) -> ErrorResult {
+    pub fn SetAlign(&mut self, _align: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 }
diff --git a/src/components/script/dom/htmllielement.rs b/src/components/script/dom/htmllielement.rs
index ea719be1362..18bd0224573 100644
--- a/src/components/script/dom/htmllielement.rs
+++ b/src/components/script/dom/htmllielement.rs
@@ -35,11 +35,11 @@ impl HTMLLIElement {
         Ok(())
     }
 
-    pub fn Type(&self) -> DOMString {
+    pub fn Type(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetType(&mut self, _type: &DOMString) -> ErrorResult {
+    pub fn SetType(&mut self, _type: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 }
diff --git a/src/components/script/dom/htmllinkelement.rs b/src/components/script/dom/htmllinkelement.rs
index 6833e457ba4..75cc63207c3 100644
--- a/src/components/script/dom/htmllinkelement.rs
+++ b/src/components/script/dom/htmllinkelement.rs
@@ -34,75 +34,75 @@ impl HTMLLinkElement {
     pub fn SetDisabled(&mut self, _disable: bool) {
     }
 
-    pub fn Href(&self) -> DOMString {
+    pub fn Href(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetHref(&mut self, _href: &DOMString) -> ErrorResult {
+    pub fn SetHref(&mut self, _href: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn CrossOrigin(&self) -> DOMString {
+    pub fn CrossOrigin(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetCrossOrigin(&mut self, _cross_origin: &DOMString) -> ErrorResult {
+    pub fn SetCrossOrigin(&mut self, _cross_origin: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Rel(&self) -> DOMString {
+    pub fn Rel(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetRel(&mut self, _rel: &DOMString) -> ErrorResult {
+    pub fn SetRel(&mut self, _rel: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Media(&self) -> DOMString {
+    pub fn Media(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetMedia(&mut self, _media: &DOMString) -> ErrorResult {
+    pub fn SetMedia(&mut self, _media: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Hreflang(&self) -> DOMString {
+    pub fn Hreflang(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetHreflang(&mut self, _href: &DOMString) -> ErrorResult {
+    pub fn SetHreflang(&mut self, _href: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Type(&self) -> DOMString {
+    pub fn Type(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetType(&mut self, _type: &DOMString) -> ErrorResult {
+    pub fn SetType(&mut self, _type: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Charset(&self) -> DOMString {
+    pub fn Charset(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetCharset(&mut self, _charset: &DOMString) -> ErrorResult {
+    pub fn SetCharset(&mut self, _charset: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Rev(&self) -> DOMString {
+    pub fn Rev(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetRev(&mut self, _rev: &DOMString) -> ErrorResult {
+    pub fn SetRev(&mut self, _rev: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Target(&self) -> DOMString {
+    pub fn Target(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetTarget(&mut self, _target: &DOMString) -> ErrorResult {
+    pub fn SetTarget(&mut self, _target: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlmapelement.rs b/src/components/script/dom/htmlmapelement.rs
index 7174f829c31..1d95436fdda 100644
--- a/src/components/script/dom/htmlmapelement.rs
+++ b/src/components/script/dom/htmlmapelement.rs
@@ -28,11 +28,11 @@ impl HTMLMapElement {
 }
 
 impl HTMLMapElement {
-    pub fn Name(&self) -> DOMString {
+    pub fn Name(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetName(&mut self, _name: &DOMString) -> ErrorResult {
+    pub fn SetName(&mut self, _name: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
diff --git a/src/components/script/dom/htmlmediaelement.rs b/src/components/script/dom/htmlmediaelement.rs
index 1daad8ecf95..073313b61ad 100644
--- a/src/components/script/dom/htmlmediaelement.rs
+++ b/src/components/script/dom/htmlmediaelement.rs
@@ -20,38 +20,38 @@ impl HTMLMediaElement {
 }
 
 impl HTMLMediaElement {
-    pub fn Src(&self) -> DOMString {
+    pub fn Src(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetSrc(&mut self, _src: &DOMString) -> ErrorResult {
+    pub fn SetSrc(&mut self, _src: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn CurrentSrc(&self) -> DOMString {
+    pub fn CurrentSrc(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn CrossOrigin(&self) -> DOMString {
+    pub fn CrossOrigin(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetCrossOrigin(&mut self, _cross_origin: &DOMString) -> ErrorResult {
+    pub fn SetCrossOrigin(&mut self, _cross_origin: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Preload(&self) -> DOMString {
+    pub fn Preload(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetPreload(&mut self, _preload: &DOMString) -> ErrorResult {
+    pub fn SetPreload(&mut self, _preload: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
     pub fn Load(&self) {
     }
 
-    pub fn CanPlayType(&self, _type: &DOMString) -> DOMString {
+    pub fn CanPlayType(&self, _type: &Option<DOMString>) -> Option<DOMString> {
         None
     }
 
diff --git a/src/components/script/dom/htmlmetaelement.rs b/src/components/script/dom/htmlmetaelement.rs
index 20a6257e74b..89a71d9aaf4 100644
--- a/src/components/script/dom/htmlmetaelement.rs
+++ b/src/components/script/dom/htmlmetaelement.rs
@@ -27,35 +27,35 @@ impl HTMLMetaElement {
 }
 
 impl HTMLMetaElement {
-    pub fn Name(&self) -> DOMString {
+    pub fn Name(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetName(&mut self, _name: &DOMString) -> ErrorResult {
+    pub fn SetName(&mut self, _name: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn HttpEquiv(&self) -> DOMString {
+    pub fn HttpEquiv(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetHttpEquiv(&mut self, _http_equiv: &DOMString) -> ErrorResult {
+    pub fn SetHttpEquiv(&mut self, _http_equiv: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Content(&self) -> DOMString {
+    pub fn Content(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetContent(&mut self, _content: &DOMString) -> ErrorResult {
+    pub fn SetContent(&mut self, _content: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Scheme(&self) -> DOMString {
+    pub fn Scheme(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetScheme(&mut self, _scheme: &DOMString) -> ErrorResult {
+    pub fn SetScheme(&mut self, _scheme: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlmodelement.rs b/src/components/script/dom/htmlmodelement.rs
index ff45b90be87..360abfdf981 100644
--- a/src/components/script/dom/htmlmodelement.rs
+++ b/src/components/script/dom/htmlmodelement.rs
@@ -27,19 +27,19 @@ impl HTMLModElement {
 }
 
 impl HTMLModElement {
-    pub fn Cite(&self) -> DOMString {
+    pub fn Cite(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetCite(&mut self, _cite: &DOMString) -> ErrorResult {
+    pub fn SetCite(&mut self, _cite: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn DateTime(&self) -> DOMString {
+    pub fn DateTime(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetDateTime(&mut self, _datetime: &DOMString) -> ErrorResult {
+    pub fn SetDateTime(&mut self, _datetime: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlobjectelement.rs b/src/components/script/dom/htmlobjectelement.rs
index 7fc29c32812..745a223645b 100644
--- a/src/components/script/dom/htmlobjectelement.rs
+++ b/src/components/script/dom/htmlobjectelement.rs
@@ -29,35 +29,35 @@ impl HTMLObjectElement {
 }
 
 impl HTMLObjectElement {
-    pub fn Data(&self) -> DOMString {
+    pub fn Data(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetData(&mut self, _data: &DOMString) -> ErrorResult {
+    pub fn SetData(&mut self, _data: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Type(&self) -> DOMString {
+    pub fn Type(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetType(&mut self, _type: &DOMString) -> ErrorResult {
+    pub fn SetType(&mut self, _type: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Name(&self) -> DOMString {
+    pub fn Name(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetName(&mut self, _name: &DOMString) -> ErrorResult {
+    pub fn SetName(&mut self, _name: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn UseMap(&self) -> DOMString {
+    pub fn UseMap(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetUseMap(&mut self, _use_map: &DOMString) -> ErrorResult {
+    pub fn SetUseMap(&mut self, _use_map: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
@@ -65,19 +65,19 @@ impl HTMLObjectElement {
         None
     }
 
-    pub fn Width(&self) -> DOMString {
+    pub fn Width(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetWidth(&mut self, _width: &DOMString) -> ErrorResult {
+    pub fn SetWidth(&mut self, _width: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Height(&self) -> DOMString {
+    pub fn Height(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetHeight(&mut self, _height: &DOMString) -> ErrorResult {
+    pub fn SetHeight(&mut self, _height: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
@@ -98,7 +98,7 @@ impl HTMLObjectElement {
         ValidityState::new(global)
     }
 
-    pub fn ValidationMessage(&self) -> DOMString {
+    pub fn ValidationMessage(&self) -> Option<DOMString> {
         None
     }
 
@@ -106,30 +106,30 @@ impl HTMLObjectElement {
         false
     }
 
-    pub fn SetCustomValidity(&mut self, _error: &DOMString) {
+    pub fn SetCustomValidity(&mut self, _error: &Option<DOMString>) {
     }
 
-    pub fn Align(&self) -> DOMString {
+    pub fn Align(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetAlign(&mut self, _align: &DOMString) -> ErrorResult {
+    pub fn SetAlign(&mut self, _align: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Archive(&self) -> DOMString {
+    pub fn Archive(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetArchive(&mut self, _archive: &DOMString) -> ErrorResult {
+    pub fn SetArchive(&mut self, _archive: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Code(&self) -> DOMString {
+    pub fn Code(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetCode(&mut self, _code: &DOMString) -> ErrorResult {
+    pub fn SetCode(&mut self, _code: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
@@ -149,11 +149,11 @@ impl HTMLObjectElement {
         Ok(())
     }
 
-    pub fn Standby(&self) -> DOMString {
+    pub fn Standby(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetStandby(&mut self, _standby: &DOMString) -> ErrorResult {
+    pub fn SetStandby(&mut self, _standby: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
@@ -165,27 +165,27 @@ impl HTMLObjectElement {
         Ok(())
     }
 
-    pub fn CodeBase(&self) -> DOMString {
+    pub fn CodeBase(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetCodeBase(&mut self, _codebase: &DOMString) -> ErrorResult {
+    pub fn SetCodeBase(&mut self, _codebase: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn CodeType(&self) -> DOMString {
+    pub fn CodeType(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetCodeType(&mut self, _codetype: &DOMString) -> ErrorResult {
+    pub fn SetCodeType(&mut self, _codetype: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Border(&self) -> DOMString {
+    pub fn Border(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetBorder(&mut self, _border: &DOMString) -> ErrorResult {
+    pub fn SetBorder(&mut self, _border: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
diff --git a/src/components/script/dom/htmlolistelement.rs b/src/components/script/dom/htmlolistelement.rs
index 1a2fd349032..781885fdb46 100644
--- a/src/components/script/dom/htmlolistelement.rs
+++ b/src/components/script/dom/htmlolistelement.rs
@@ -43,11 +43,11 @@ impl HTMLOListElement {
         Ok(())
     }
 
-    pub fn Type(&self) -> DOMString {
+    pub fn Type(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetType(&mut self, _type: &DOMString) -> ErrorResult {
+    pub fn SetType(&mut self, _type: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
diff --git a/src/components/script/dom/htmloptgroupelement.rs b/src/components/script/dom/htmloptgroupelement.rs
index 0bd13fbd6e3..ce76e75031a 100644
--- a/src/components/script/dom/htmloptgroupelement.rs
+++ b/src/components/script/dom/htmloptgroupelement.rs
@@ -35,11 +35,11 @@ impl HTMLOptGroupElement {
         Ok(())
     }
 
-    pub fn Label(&self) -> DOMString {
+    pub fn Label(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetLabel(&mut self, _label: &DOMString) -> ErrorResult {
+    pub fn SetLabel(&mut self, _label: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 }
diff --git a/src/components/script/dom/htmloptionelement.rs b/src/components/script/dom/htmloptionelement.rs
index 4f7adb4b845..d5674e9cd47 100644
--- a/src/components/script/dom/htmloptionelement.rs
+++ b/src/components/script/dom/htmloptionelement.rs
@@ -39,11 +39,11 @@ impl HTMLOptionElement {
         None
     }
 
-    pub fn Label(&self) -> DOMString {
+    pub fn Label(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetLabel(&mut self, _label: &DOMString) -> ErrorResult {
+    pub fn SetLabel(&mut self, _label: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
@@ -63,19 +63,19 @@ impl HTMLOptionElement {
         Ok(())
     }
 
-    pub fn Value(&self) -> DOMString {
+    pub fn Value(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetValue(&mut self, _value: &DOMString) -> ErrorResult {
+    pub fn SetValue(&mut self, _value: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Text(&self) -> DOMString {
+    pub fn Text(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetText(&mut self, _text: &DOMString) -> ErrorResult {
+    pub fn SetText(&mut self, _text: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
diff --git a/src/components/script/dom/htmloutputelement.rs b/src/components/script/dom/htmloutputelement.rs
index 8c5832f1d6a..1c3689cdf53 100644
--- a/src/components/script/dom/htmloutputelement.rs
+++ b/src/components/script/dom/htmloutputelement.rs
@@ -32,31 +32,31 @@ impl HTMLOutputElement {
         None
     }
 
-    pub fn Name(&self) -> DOMString {
+    pub fn Name(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetName(&mut self, _name: &DOMString) -> ErrorResult {
+    pub fn SetName(&mut self, _name: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Type(&self) -> DOMString {
+    pub fn Type(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn DefaultValue(&self) -> DOMString {
+    pub fn DefaultValue(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetDefaultValue(&mut self, _value: &DOMString) -> ErrorResult {
+    pub fn SetDefaultValue(&mut self, _value: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Value(&self) -> DOMString {
+    pub fn Value(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetValue(&mut self, _value: &DOMString) -> ErrorResult {
+    pub fn SetValue(&mut self, _value: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
@@ -75,11 +75,11 @@ impl HTMLOutputElement {
     pub fn SetValidity(&mut self, _validity: @mut ValidityState) {
     }
 
-    pub fn ValidationMessage(&self) -> DOMString {
+    pub fn ValidationMessage(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetValidationMessage(&mut self, _message: &DOMString) -> ErrorResult {
+    pub fn SetValidationMessage(&mut self, _message: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
@@ -87,6 +87,6 @@ impl HTMLOutputElement {
         true
     }
 
-    pub fn SetCustomValidity(&mut self, _error: &DOMString) {
+    pub fn SetCustomValidity(&mut self, _error: &Option<DOMString>) {
     }
 }
diff --git a/src/components/script/dom/htmlparagraphelement.rs b/src/components/script/dom/htmlparagraphelement.rs
index 2c07892f7e6..b88e8bc9913 100644
--- a/src/components/script/dom/htmlparagraphelement.rs
+++ b/src/components/script/dom/htmlparagraphelement.rs
@@ -27,11 +27,11 @@ impl HTMLParagraphElement {
 }
 
 impl HTMLParagraphElement {
-    pub fn Align(&self) -> DOMString {
+    pub fn Align(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetAlign(&mut self, _align: &DOMString) -> ErrorResult {
+    pub fn SetAlign(&mut self, _align: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlparamelement.rs b/src/components/script/dom/htmlparamelement.rs
index b97eb017872..c7259b219a8 100644
--- a/src/components/script/dom/htmlparamelement.rs
+++ b/src/components/script/dom/htmlparamelement.rs
@@ -27,35 +27,35 @@ impl HTMLParamElement {
 }
 
 impl HTMLParamElement {
-    pub fn Name(&self) -> DOMString {
+    pub fn Name(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetName(&mut self, _name: &DOMString) -> ErrorResult {
+    pub fn SetName(&mut self, _name: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Value(&self) -> DOMString {
+    pub fn Value(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetValue(&mut self, _value: &DOMString) -> ErrorResult {
+    pub fn SetValue(&mut self, _value: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Type(&self) -> DOMString {
+    pub fn Type(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetType(&mut self, _type: &DOMString) -> ErrorResult {
+    pub fn SetType(&mut self, _type: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn ValueType(&self) -> DOMString {
+    pub fn ValueType(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetValueType(&mut self, _value_type: &DOMString) -> ErrorResult {
+    pub fn SetValueType(&mut self, _value_type: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlquoteelement.rs b/src/components/script/dom/htmlquoteelement.rs
index 5b03188c9c6..c1955020b19 100644
--- a/src/components/script/dom/htmlquoteelement.rs
+++ b/src/components/script/dom/htmlquoteelement.rs
@@ -27,11 +27,11 @@ impl HTMLQuoteElement {
 }
 
 impl HTMLQuoteElement {
-    pub fn Cite(&self) -> DOMString {
+    pub fn Cite(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetCite(&self, _cite: &DOMString) -> ErrorResult {
+    pub fn SetCite(&self, _cite: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlscriptelement.rs b/src/components/script/dom/htmlscriptelement.rs
index ea47c904f1f..e416bf8bc64 100644
--- a/src/components/script/dom/htmlscriptelement.rs
+++ b/src/components/script/dom/htmlscriptelement.rs
@@ -28,27 +28,27 @@ impl HTMLScriptElement {
 }
 
 impl HTMLScriptElement {
-    pub fn Src(&self) -> DOMString {
+    pub fn Src(&self) -> Option<DOMString> {
         self.htmlelement.element.get_attr("src").map(|s| s.to_str())
     }
 
-    pub fn SetSrc(&mut self, _src: &DOMString) -> ErrorResult {
+    pub fn SetSrc(&mut self, _src: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Type(&self) -> DOMString {
+    pub fn Type(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetType(&mut self, _type: &DOMString) -> ErrorResult {
+    pub fn SetType(&mut self, _type: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Charset(&self) -> DOMString {
+    pub fn Charset(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetCharset(&mut self, _charset: &DOMString) -> ErrorResult {
+    pub fn SetCharset(&mut self, _charset: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
@@ -68,35 +68,35 @@ impl HTMLScriptElement {
         Ok(())
     }
 
-    pub fn CrossOrigin(&self) -> DOMString {
+    pub fn CrossOrigin(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetCrossOrigin(&mut self, _cross_origin: &DOMString) -> ErrorResult {
+    pub fn SetCrossOrigin(&mut self, _cross_origin: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Text(&self) -> DOMString {
+    pub fn Text(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetText(&mut self, _text: &DOMString) -> ErrorResult {
+    pub fn SetText(&mut self, _text: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Event(&self) -> DOMString {
+    pub fn Event(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetEvent(&mut self, _event: &DOMString) -> ErrorResult {
+    pub fn SetEvent(&mut self, _event: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn HtmlFor(&self) -> DOMString {
+    pub fn HtmlFor(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetHtmlFor(&mut self, _html_for: &DOMString) -> ErrorResult {
+    pub fn SetHtmlFor(&mut self, _html_for: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlselectelement.rs b/src/components/script/dom/htmlselectelement.rs
index bda52c7ed18..1676672816b 100644
--- a/src/components/script/dom/htmlselectelement.rs
+++ b/src/components/script/dom/htmlselectelement.rs
@@ -56,11 +56,11 @@ impl HTMLSelectElement {
         Ok(())
     }
 
-    pub fn Name(&self) -> DOMString {
+    pub fn Name(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetName(&mut self, _name: &DOMString) -> ErrorResult {
+    pub fn SetName(&mut self, _name: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
@@ -80,7 +80,7 @@ impl HTMLSelectElement {
         Ok(())
     }
 
-    pub fn Type(&self) -> DOMString {
+    pub fn Type(&self) -> Option<DOMString> {
         None
     }
 
@@ -96,7 +96,7 @@ impl HTMLSelectElement {
         None
     }
 
-    pub fn NamedItem(&self, _name: &DOMString) -> Option<AbstractNode<ScriptView>> {
+    pub fn NamedItem(&self, _name: &Option<DOMString>) -> Option<AbstractNode<ScriptView>> {
         None
     }
 
@@ -122,11 +122,11 @@ impl HTMLSelectElement {
         Ok(())
     }
 
-    pub fn Value(&self) -> DOMString {
+    pub fn Value(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetValue(&mut self, _value: &DOMString) {
+    pub fn SetValue(&mut self, _value: &Option<DOMString>) {
     }
 
     pub fn WillValidate(&self) -> bool {
@@ -144,11 +144,11 @@ impl HTMLSelectElement {
     pub fn SetValidity(&mut self, _validity: @mut ValidityState) {
     }
 
-    pub fn ValidationMessage(&self) -> DOMString {
+    pub fn ValidationMessage(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetValidationMessage(&mut self, _message: &DOMString) -> ErrorResult {
+    pub fn SetValidationMessage(&mut self, _message: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
@@ -156,6 +156,6 @@ impl HTMLSelectElement {
         true
     }
 
-    pub fn SetCustomValidity(&mut self, _error: &DOMString) {
+    pub fn SetCustomValidity(&mut self, _error: &Option<DOMString>) {
     }
 }
diff --git a/src/components/script/dom/htmlsourceelement.rs b/src/components/script/dom/htmlsourceelement.rs
index 89933a7478a..52974594bf6 100644
--- a/src/components/script/dom/htmlsourceelement.rs
+++ b/src/components/script/dom/htmlsourceelement.rs
@@ -27,27 +27,27 @@ impl HTMLSourceElement {
 }
 
 impl HTMLSourceElement {
-    pub fn Src(&self) -> DOMString {
+    pub fn Src(&self) -> Option<DOMString> {
         None
     }
     
-    pub fn SetSrc(&mut self, _src: &DOMString) -> ErrorResult {
+    pub fn SetSrc(&mut self, _src: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Type(&self) -> DOMString {
+    pub fn Type(&self) -> Option<DOMString> {
         None
     }
     
-    pub fn SetType(&mut self, _type: &DOMString) -> ErrorResult {
+    pub fn SetType(&mut self, _type: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Media(&self) -> DOMString {
+    pub fn Media(&self) -> Option<DOMString> {
         None
     }
     
-    pub fn SetMedia(&mut self, _media: &DOMString) -> ErrorResult {
+    pub fn SetMedia(&mut self, _media: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlstyleelement.rs b/src/components/script/dom/htmlstyleelement.rs
index 88c933d851e..cf18b229f8e 100644
--- a/src/components/script/dom/htmlstyleelement.rs
+++ b/src/components/script/dom/htmlstyleelement.rs
@@ -34,19 +34,19 @@ impl HTMLStyleElement {
     pub fn SetDisabled(&self, _disabled: bool) {
     }
 
-    pub fn Media(&self) -> DOMString {
+    pub fn Media(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetMedia(&mut self, _media: &DOMString) -> ErrorResult {
+    pub fn SetMedia(&mut self, _media: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Type(&self) -> DOMString {
+    pub fn Type(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetType(&mut self, _type: &DOMString) -> ErrorResult {
+    pub fn SetType(&mut self, _type: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
diff --git a/src/components/script/dom/htmltablecaptionelement.rs b/src/components/script/dom/htmltablecaptionelement.rs
index 788e239344a..93be5a96013 100644
--- a/src/components/script/dom/htmltablecaptionelement.rs
+++ b/src/components/script/dom/htmltablecaptionelement.rs
@@ -27,11 +27,11 @@ impl HTMLTableCaptionElement {
 }
 
 impl HTMLTableCaptionElement {
-    pub fn Align(&self) -> DOMString {
+    pub fn Align(&self) -> Option<DOMString> {
         None
     }
     
-    pub fn SetAlign(&mut self, _align: &DOMString) -> ErrorResult {
+    pub fn SetAlign(&mut self, _align: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 }
diff --git a/src/components/script/dom/htmltablecellelement.rs b/src/components/script/dom/htmltablecellelement.rs
index 9869bf3fb7f..a0f5bfdfc12 100644
--- a/src/components/script/dom/htmltablecellelement.rs
+++ b/src/components/script/dom/htmltablecellelement.rs
@@ -36,11 +36,11 @@ impl HTMLTableCellElement {
         Ok(())
     }
 
-    pub fn Headers(&self) -> DOMString {
+    pub fn Headers(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetHeaders(&self, _headers: &DOMString) -> ErrorResult {
+    pub fn SetHeaders(&self, _headers: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
@@ -52,67 +52,67 @@ impl HTMLTableCellElement {
         Ok(())
     }
 
-    pub fn Abbr(&self) -> DOMString {
+    pub fn Abbr(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetAbbr(&self, _abbr: &DOMString) -> ErrorResult {
+    pub fn SetAbbr(&self, _abbr: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Scope(&self) -> DOMString {
+    pub fn Scope(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetScope(&self, _abbr: &DOMString) -> ErrorResult {
+    pub fn SetScope(&self, _abbr: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Align(&self) -> DOMString {
+    pub fn Align(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetAlign(&self, _align: &DOMString) -> ErrorResult {
+    pub fn SetAlign(&self, _align: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Axis(&self) -> DOMString {
+    pub fn Axis(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetAxis(&self, _axis: &DOMString) -> ErrorResult {
+    pub fn SetAxis(&self, _axis: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Height(&self) -> DOMString {
+    pub fn Height(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetHeight(&self, _height: &DOMString) -> ErrorResult {
+    pub fn SetHeight(&self, _height: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Width(&self) -> DOMString {
+    pub fn Width(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetWidth(&self, _width: &DOMString) -> ErrorResult {
+    pub fn SetWidth(&self, _width: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Ch(&self) -> DOMString {
+    pub fn Ch(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetCh(&self, _ch: &DOMString) -> ErrorResult {
+    pub fn SetCh(&self, _ch: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn ChOff(&self) -> DOMString {
+    pub fn ChOff(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetChOff(&self, _ch_off: &DOMString) -> ErrorResult {
+    pub fn SetChOff(&self, _ch_off: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
@@ -124,19 +124,19 @@ impl HTMLTableCellElement {
         Ok(())
     }
 
-    pub fn VAlign(&self) -> DOMString {
+    pub fn VAlign(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetVAlign(&self, _valign: &DOMString) -> ErrorResult {
+    pub fn SetVAlign(&self, _valign: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn BgColor(&self) -> DOMString {
+    pub fn BgColor(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetBgColor(&self, _bg_color: &DOMString) -> ErrorResult {
+    pub fn SetBgColor(&self, _bg_color: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 }
diff --git a/src/components/script/dom/htmltablecolelement.rs b/src/components/script/dom/htmltablecolelement.rs
index 633e40e60f8..ddce6ff8a75 100644
--- a/src/components/script/dom/htmltablecolelement.rs
+++ b/src/components/script/dom/htmltablecolelement.rs
@@ -35,43 +35,43 @@ impl HTMLTableColElement {
         Ok(())
     }
 
-    pub fn Align(&self) -> DOMString {
+    pub fn Align(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetAlign(&mut self, _align: &DOMString) -> ErrorResult {
+    pub fn SetAlign(&mut self, _align: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Ch(&self) -> DOMString {
+    pub fn Ch(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetCh(&mut self, _ch: &DOMString) -> ErrorResult {
+    pub fn SetCh(&mut self, _ch: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn ChOff(&self) -> DOMString {
+    pub fn ChOff(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetChOff(&mut self, _ch_off: &DOMString) -> ErrorResult {
+    pub fn SetChOff(&mut self, _ch_off: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn VAlign(&self) -> DOMString {
+    pub fn VAlign(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetVAlign(&mut self, _v_align: &DOMString) -> ErrorResult {
+    pub fn SetVAlign(&mut self, _v_align: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Width(&self) -> DOMString {
+    pub fn Width(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetWidth(&mut self, _width: &DOMString) -> ErrorResult {
+    pub fn SetWidth(&mut self, _width: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 }
diff --git a/src/components/script/dom/htmltableelement.rs b/src/components/script/dom/htmltableelement.rs
index 9456c8554ed..b06e0d7c220 100644
--- a/src/components/script/dom/htmltableelement.rs
+++ b/src/components/script/dom/htmltableelement.rs
@@ -50,75 +50,75 @@ impl HTMLTableElement {
     pub fn StopSorting(&self) {
     }
 
-    pub fn Align(&self) -> DOMString {
+    pub fn Align(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetAlign(&self, _align: &DOMString) -> ErrorResult {
+    pub fn SetAlign(&self, _align: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Border(&self) -> DOMString {
+    pub fn Border(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetBorder(&self, _border: &DOMString) -> ErrorResult {
+    pub fn SetBorder(&self, _border: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Frame(&self) -> DOMString {
+    pub fn Frame(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetFrame(&self, _frame: &DOMString) -> ErrorResult {
+    pub fn SetFrame(&self, _frame: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Rules(&self) -> DOMString {
+    pub fn Rules(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetRules(&self, _rules: &DOMString) -> ErrorResult {
+    pub fn SetRules(&self, _rules: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Summary(&self) -> DOMString {
+    pub fn Summary(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetSummary(&self, _summary: &DOMString) -> ErrorResult {
+    pub fn SetSummary(&self, _summary: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Width(&self) -> DOMString {
+    pub fn Width(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetWidth(&self, _width: &DOMString) -> ErrorResult {
+    pub fn SetWidth(&self, _width: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn BgColor(&self) -> DOMString {
+    pub fn BgColor(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetBgColor(&self, _bg_color: &DOMString) -> ErrorResult {
+    pub fn SetBgColor(&self, _bg_color: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn CellPadding(&self) -> DOMString {
+    pub fn CellPadding(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetCellPadding(&self, _cell_padding: &DOMString) -> ErrorResult {
+    pub fn SetCellPadding(&self, _cell_padding: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn CellSpacing(&self) -> DOMString {
+    pub fn CellSpacing(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetCellSpacing(&self, _cell_spacing: &DOMString) -> ErrorResult {
+    pub fn SetCellSpacing(&self, _cell_spacing: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 }
diff --git a/src/components/script/dom/htmltablerowelement.rs b/src/components/script/dom/htmltablerowelement.rs
index de22597d057..d363192707d 100644
--- a/src/components/script/dom/htmltablerowelement.rs
+++ b/src/components/script/dom/htmltablerowelement.rs
@@ -47,43 +47,43 @@ impl HTMLTableRowElement {
         Ok(())
     }
 
-    pub fn Align(&self) -> DOMString {
+    pub fn Align(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetAlign(&self, _align: &DOMString) -> ErrorResult {
+    pub fn SetAlign(&self, _align: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Ch(&self) -> DOMString {
+    pub fn Ch(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetCh(&self, _ch: &DOMString) -> ErrorResult {
+    pub fn SetCh(&self, _ch: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn ChOff(&self) -> DOMString {
+    pub fn ChOff(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetChOff(&self, _ch_off: &DOMString) -> ErrorResult {
+    pub fn SetChOff(&self, _ch_off: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn VAlign(&self) -> DOMString {
+    pub fn VAlign(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetVAlign(&self, _v_align: &DOMString) -> ErrorResult {
+    pub fn SetVAlign(&self, _v_align: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn BgColor(&self) -> DOMString {
+    pub fn BgColor(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetBgColor(&self, _bg_color: &DOMString) -> ErrorResult {
+    pub fn SetBgColor(&self, _bg_color: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 }
diff --git a/src/components/script/dom/htmltablesectionelement.rs b/src/components/script/dom/htmltablesectionelement.rs
index 8133e768ea3..90a1d0f0bcb 100644
--- a/src/components/script/dom/htmltablesectionelement.rs
+++ b/src/components/script/dom/htmltablesectionelement.rs
@@ -31,35 +31,35 @@ impl HTMLTableSectionElement {
         Ok(())
     }
 
-    pub fn Align(&self) -> DOMString {
+    pub fn Align(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetAlign(&mut self, _align: &DOMString) -> ErrorResult {
+    pub fn SetAlign(&mut self, _align: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Ch(&self) -> DOMString {
+    pub fn Ch(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetCh(&mut self, _ch: &DOMString) -> ErrorResult {
+    pub fn SetCh(&mut self, _ch: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn ChOff(&self) -> DOMString {
+    pub fn ChOff(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetChOff(&mut self, _ch_off: &DOMString) -> ErrorResult {
+    pub fn SetChOff(&mut self, _ch_off: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn VAlign(&self) -> DOMString {
+    pub fn VAlign(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetVAlign(&mut self, _v_align: &DOMString) -> ErrorResult {
+    pub fn SetVAlign(&mut self, _v_align: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 }
diff --git a/src/components/script/dom/htmltextareaelement.rs b/src/components/script/dom/htmltextareaelement.rs
index 5065d90a76e..e92fb1cc7c4 100644
--- a/src/components/script/dom/htmltextareaelement.rs
+++ b/src/components/script/dom/htmltextareaelement.rs
@@ -59,19 +59,19 @@ impl HTMLTextAreaElement {
         Ok(())
     }
 
-    pub fn Name(&self) -> DOMString {
+    pub fn Name(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetName(&mut self, _name: &DOMString) -> ErrorResult {
+    pub fn SetName(&mut self, _name: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Placeholder(&self) -> DOMString {
+    pub fn Placeholder(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetPlaceholder(&mut self, _placeholder: &DOMString) -> ErrorResult {
+    pub fn SetPlaceholder(&mut self, _placeholder: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
@@ -99,34 +99,34 @@ impl HTMLTextAreaElement {
         Ok(())
     }
 
-    pub fn Wrap(&self) -> DOMString {
+    pub fn Wrap(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetWrap(&mut self, _wrap: &DOMString) -> ErrorResult {
+    pub fn SetWrap(&mut self, _wrap: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Type(&self) -> DOMString {
+    pub fn Type(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetType(&mut self, _type: &DOMString) {
+    pub fn SetType(&mut self, _type: &Option<DOMString>) {
     }
 
-    pub fn DefaultValue(&self) -> DOMString {
+    pub fn DefaultValue(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetDefaultValue(&mut self, _default_value: &DOMString) -> ErrorResult {
+    pub fn SetDefaultValue(&mut self, _default_value: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Value(&self) -> DOMString {
+    pub fn Value(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetValue(&mut self, _value: &DOMString) {
+    pub fn SetValue(&mut self, _value: &Option<DOMString>) {
     }
 
     pub fn TextLength(&self) -> u32 {
@@ -145,7 +145,7 @@ impl HTMLTextAreaElement {
         Ok(())
     }
 
-    pub fn ValidationMessage(&self) -> DOMString {
+    pub fn ValidationMessage(&self) -> Option<DOMString> {
         None
     }
 
@@ -153,7 +153,7 @@ impl HTMLTextAreaElement {
         false
     }
 
-    pub fn SetCustomValidity(&self, _error: &DOMString) {
+    pub fn SetCustomValidity(&self, _error: &Option<DOMString>) {
     }
 
     pub fn Select(&self) {
@@ -175,14 +175,14 @@ impl HTMLTextAreaElement {
         Ok(())
     }
 
-    pub fn GetSelectionDirection(&self) -> Fallible<DOMString> {
+    pub fn GetSelectionDirection(&self) -> Fallible<Option<DOMString>> {
         Ok(None)
     }
 
-    pub fn SetSelectionDirection(&self, _selection_direction: &DOMString) -> ErrorResult {
+    pub fn SetSelectionDirection(&self, _selection_direction: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn SetRangeText(&self, _replacement: &DOMString) {
+    pub fn SetRangeText(&self, _replacement: &Option<DOMString>) {
     }
 }
diff --git a/src/components/script/dom/htmltimeelement.rs b/src/components/script/dom/htmltimeelement.rs
index 93c6081cb62..bb3328808e6 100644
--- a/src/components/script/dom/htmltimeelement.rs
+++ b/src/components/script/dom/htmltimeelement.rs
@@ -27,11 +27,11 @@ impl HTMLTimeElement {
 }
 
 impl HTMLTimeElement {
-    pub fn DateTime(&self) -> DOMString {
+    pub fn DateTime(&self) -> Option<DOMString> {
         None
     }
     
-    pub fn SetDateTime(&mut self, _dateTime: &DOMString) -> ErrorResult {
+    pub fn SetDateTime(&mut self, _dateTime: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 }
diff --git a/src/components/script/dom/htmltitleelement.rs b/src/components/script/dom/htmltitleelement.rs
index fd646b5b797..eb0831e519a 100644
--- a/src/components/script/dom/htmltitleelement.rs
+++ b/src/components/script/dom/htmltitleelement.rs
@@ -27,11 +27,11 @@ impl HTMLTitleElement {
 }
 
 impl HTMLTitleElement {
-    pub fn Text(&self) -> DOMString {
+    pub fn Text(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetText(&mut self, _text: &DOMString) -> ErrorResult {
+    pub fn SetText(&mut self, _text: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 }
diff --git a/src/components/script/dom/htmltrackelement.rs b/src/components/script/dom/htmltrackelement.rs
index 1a5a2072356..d6aacdb3b45 100644
--- a/src/components/script/dom/htmltrackelement.rs
+++ b/src/components/script/dom/htmltrackelement.rs
@@ -27,35 +27,35 @@ impl HTMLTrackElement {
 }
 
 impl HTMLTrackElement {
-    pub fn Kind(&self) -> DOMString {
+    pub fn Kind(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetKind(&mut self, _kind: &DOMString) -> ErrorResult {
+    pub fn SetKind(&mut self, _kind: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Src(&self) -> DOMString {
+    pub fn Src(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetSrc(&mut self, _src: &DOMString) -> ErrorResult {
+    pub fn SetSrc(&mut self, _src: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Srclang(&self) -> DOMString {
+    pub fn Srclang(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetSrclang(&mut self, _srclang: &DOMString) -> ErrorResult {
+    pub fn SetSrclang(&mut self, _srclang: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn Label(&self) -> DOMString {
+    pub fn Label(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetLabel(&mut self, _label: &DOMString) -> ErrorResult {
+    pub fn SetLabel(&mut self, _label: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
diff --git a/src/components/script/dom/htmlulistelement.rs b/src/components/script/dom/htmlulistelement.rs
index ee7df48009a..d559ae60ff1 100644
--- a/src/components/script/dom/htmlulistelement.rs
+++ b/src/components/script/dom/htmlulistelement.rs
@@ -35,11 +35,11 @@ impl HTMLUListElement {
         Ok(())
     }
 
-    pub fn Type(&self) -> DOMString {
+    pub fn Type(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetType(&mut self, _type: &DOMString) -> ErrorResult {
+    pub fn SetType(&mut self, _type: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlvideoelement.rs b/src/components/script/dom/htmlvideoelement.rs
index b78e13947e8..f5d34487ff3 100644
--- a/src/components/script/dom/htmlvideoelement.rs
+++ b/src/components/script/dom/htmlvideoelement.rs
@@ -51,11 +51,11 @@ impl HTMLVideoElement {
         0
     }
 
-    pub fn Poster(&self) -> DOMString {
+    pub fn Poster(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetPoster(&mut self, _poster: &DOMString) -> ErrorResult {
+    pub fn SetPoster(&mut self, _poster: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 }
diff --git a/src/components/script/dom/mouseevent.rs b/src/components/script/dom/mouseevent.rs
index 30dae36521e..bcc69a7ebac 100644
--- a/src/components/script/dom/mouseevent.rs
+++ b/src/components/script/dom/mouseevent.rs
@@ -49,7 +49,7 @@ impl MouseEvent {
     }
 
     pub fn Constructor(owner: @mut Window,
-                       type_: &DOMString,
+                       type_: &Option<DOMString>,
                        init: &MouseEventBinding::MouseEventInit) -> Fallible<AbstractEvent> {
         let ev = MouseEvent::new(owner);
         ev.mut_mouseevent().InitMouseEvent(type_, init.bubbles, init.cancelable, init.view,
@@ -105,13 +105,13 @@ impl MouseEvent {
         self.related_target
     }
 
-    pub fn GetModifierState(&self, _keyArg: &DOMString) -> bool {
+    pub fn GetModifierState(&self, _keyArg: &Option<DOMString>) -> bool {
         //TODO
         false
     }
 
     pub fn InitMouseEvent(&mut self,
-                          typeArg: &DOMString,
+                          typeArg: &Option<DOMString>,
                           canBubbleArg: bool,
                           cancelableArg: bool,
                           viewArg: Option<@mut WindowProxy>,
diff --git a/src/components/script/dom/namespace.rs b/src/components/script/dom/namespace.rs
index 7fe8e68e232..5603c67f410 100644
--- a/src/components/script/dom/namespace.rs
+++ b/src/components/script/dom/namespace.rs
@@ -17,7 +17,7 @@ pub enum Namespace {
 }
 
 impl Namespace {
-    pub fn from_str(url: &DOMString) -> Namespace {
+    pub fn from_str(url: &Option<DOMString>) -> Namespace {
         match null_str_as_empty_ref(url) {
             &"http://www.w3.org/1999/xhtml" => HTML,
             &"http://www.w3.org/XML/1998/namespace" => XML,
@@ -29,7 +29,7 @@ impl Namespace {
             ns => Other(ns.to_owned())
         }
     }
-    pub fn to_str(&self) -> DOMString {
+    pub fn to_str(&self) -> Option<DOMString> {
         match *self {
             Null => None,
             HTML => Some(~"http://www.w3.org/1999/xhtml"),
diff --git a/src/components/script/dom/navigator.rs b/src/components/script/dom/navigator.rs
index 7dbd81959b5..7fd782c9731 100644
--- a/src/components/script/dom/navigator.rs
+++ b/src/components/script/dom/navigator.rs
@@ -22,23 +22,23 @@ impl Navigator {
         reflect_dom_object(@mut Navigator::new_inherited(), window, NavigatorBinding::Wrap)
     }
 
-    pub fn DoNotTrack(&self) -> DOMString {
+    pub fn DoNotTrack(&self) -> Option<DOMString> {
         Some(~"unspecified")
     }
 
-    pub fn Vendor(&self) -> DOMString {
+    pub fn Vendor(&self) -> Option<DOMString> {
         Some(~"") // Like Gecko
     }
 
-    pub fn VendorSub(&self) -> DOMString {
+    pub fn VendorSub(&self) -> Option<DOMString> {
         Some(~"") // Like Gecko
     }
 
-    pub fn Product(&self) -> DOMString {
+    pub fn Product(&self) -> Option<DOMString> {
         Some(~"Gecko") // This is supposed to be constant, see webidl.
     }
 
-    pub fn ProductSub(&self) -> DOMString {
+    pub fn ProductSub(&self) -> Option<DOMString> {
         None
     }
 
@@ -46,7 +46,7 @@ impl Navigator {
         false
     }
 
-    pub fn GetBuildID(&self) -> Fallible<DOMString> {
+    pub fn GetBuildID(&self) -> Fallible<Option<DOMString>> {
         Ok(None)
     }
 
@@ -58,27 +58,27 @@ impl Navigator {
         false
     }
 
-    pub fn AppName(&self) -> DOMString {
+    pub fn AppName(&self) -> Option<DOMString> {
         Some(~"Netscape") // Like Gecko/Webkit
     }
 
-    pub fn GetAppCodeName(&self) -> Fallible<DOMString> {
+    pub fn GetAppCodeName(&self) -> Fallible<Option<DOMString>> {
         Ok(Some(~"Mozilla")) // Like Gecko/Webkit
     }
 
-    pub fn GetAppVersion(&self) -> Fallible<DOMString> {
+    pub fn GetAppVersion(&self) -> Fallible<Option<DOMString>> {
         Ok(None)
     }
 
-    pub fn GetPlatform(&self) -> Fallible<DOMString> {
+    pub fn GetPlatform(&self) -> Fallible<Option<DOMString>> {
         Ok(None)
     }
 
-    pub fn GetUserAgent(&self) -> Fallible<DOMString> {
+    pub fn GetUserAgent(&self) -> Fallible<Option<DOMString>> {
         Ok(None)
     }
 
-    pub fn GetLanguage(&self) -> DOMString {
+    pub fn GetLanguage(&self) -> Option<DOMString> {
         None
     }
 
diff --git a/src/components/script/dom/node.rs b/src/components/script/dom/node.rs
index a6cf77d0c19..9b3468688d2 100644
--- a/src/components/script/dom/node.rs
+++ b/src/components/script/dom/node.rs
@@ -561,7 +561,7 @@ impl Node<ScriptView> {
         }
     }
 
-    pub fn NodeName(&self, abstract_self: AbstractNode<ScriptView>) -> DOMString {
+    pub fn NodeName(&self, abstract_self: AbstractNode<ScriptView>) -> Option<DOMString> {
         Some(match self.type_id {
             ElementNodeTypeId(*) => {
                 do abstract_self.with_imm_element |element| {
@@ -580,7 +580,7 @@ impl Node<ScriptView> {
         })
     }
 
-    pub fn GetBaseURI(&self) -> DOMString {
+    pub fn GetBaseURI(&self) -> Option<DOMString> {
         None
     }
 
@@ -623,7 +623,7 @@ impl Node<ScriptView> {
         self.next_sibling
     }
 
-    pub fn GetNodeValue(&self, abstract_self: AbstractNode<ScriptView>) -> DOMString {
+    pub fn GetNodeValue(&self, abstract_self: AbstractNode<ScriptView>) -> Option<DOMString> {
         match self.type_id {
             // ProcessingInstruction
             CommentNodeTypeId | TextNodeTypeId => {
@@ -637,11 +637,11 @@ impl Node<ScriptView> {
         }
     }
 
-    pub fn SetNodeValue(&mut self, _abstract_self: AbstractNode<ScriptView>, _val: &DOMString) -> ErrorResult {
+    pub fn SetNodeValue(&mut self, _abstract_self: AbstractNode<ScriptView>, _val: &Option<DOMString>) -> ErrorResult {
         Ok(())
     }
 
-    pub fn GetTextContent(&self, abstract_self: AbstractNode<ScriptView>) -> DOMString {
+    pub fn GetTextContent(&self, abstract_self: AbstractNode<ScriptView>) -> Option<DOMString> {
         match self.type_id {
           DocumentFragmentNodeTypeId | ElementNodeTypeId(*) => {
             let mut content = ~"";
@@ -939,7 +939,7 @@ impl Node<ScriptView> {
 
     pub fn SetTextContent(&mut self,
                           abstract_self: AbstractNode<ScriptView>,
-                          value: &DOMString) -> ErrorResult {
+                          value: &Option<DOMString>) -> ErrorResult {
         let is_empty = match value {
             &Some(~"") | &None => true,
             _ => false
@@ -1019,27 +1019,27 @@ impl Node<ScriptView> {
         false
     }
 
-    pub fn LookupPrefix(&self, _prefix: &DOMString) -> DOMString {
+    pub fn LookupPrefix(&self, _prefix: &Option<DOMString>) -> Option<DOMString> {
         None
     }
 
-    pub fn LookupNamespaceURI(&self, _namespace: &DOMString) -> DOMString {
+    pub fn LookupNamespaceURI(&self, _namespace: &Option<DOMString>) -> Option<DOMString> {
         None
     }
 
-    pub fn IsDefaultNamespace(&self, _namespace: &DOMString) -> bool {
+    pub fn IsDefaultNamespace(&self, _namespace: &Option<DOMString>) -> bool {
         false
     }
 
-    pub fn GetNamespaceURI(&self) -> DOMString {
+    pub fn GetNamespaceURI(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn GetPrefix(&self) -> DOMString {
+    pub fn GetPrefix(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn GetLocalName(&self) -> DOMString {
+    pub fn GetLocalName(&self) -> Option<DOMString> {
         None
     }
 
diff --git a/src/components/script/dom/text.rs b/src/components/script/dom/text.rs
index e0fd493d887..b7b49ad3d3d 100644
--- a/src/components/script/dom/text.rs
+++ b/src/components/script/dom/text.rs
@@ -26,7 +26,7 @@ impl Text {
         Node::reflect_node(@mut node, document, TextBinding::Wrap)
     }
 
-    pub fn Constructor(owner: @mut Window, text: &DOMString) -> Fallible<AbstractNode<ScriptView>> {
+    pub fn Constructor(owner: @mut Window, text: &Option<DOMString>) -> Fallible<AbstractNode<ScriptView>> {
         Ok(Text::new(null_str_as_empty(text), owner.Document()))
     }
 
@@ -34,7 +34,7 @@ impl Text {
         fail!("unimplemented")
     }
 
-    pub fn GetWholeText(&self) -> Fallible<DOMString> {
+    pub fn GetWholeText(&self) -> Fallible<Option<DOMString>> {
         Ok(None)
     }
 }
diff --git a/src/components/script/dom/uievent.rs b/src/components/script/dom/uievent.rs
index b3a48c69d2b..313f658ee20 100644
--- a/src/components/script/dom/uievent.rs
+++ b/src/components/script/dom/uievent.rs
@@ -33,7 +33,7 @@ impl UIEvent {
     }
 
     pub fn Constructor(owner: @mut Window,
-                       type_: &DOMString,
+                       type_: &Option<DOMString>,
                        init: &UIEventBinding::UIEventInit) -> Fallible<AbstractEvent> {
         let ev = UIEvent::new(owner, UIEventTypeId);
         ev.mut_uievent().InitUIEvent(type_, init.parent.bubbles, init.parent.cancelable,
@@ -50,7 +50,7 @@ impl UIEvent {
     }
 
     pub fn InitUIEvent(&mut self,
-                       type_: &DOMString,
+                       type_: &Option<DOMString>,
                        can_bubble: bool,
                        cancelable: bool,
                        view: Option<@mut WindowProxy>,
diff --git a/src/components/script/dom/window.rs b/src/components/script/dom/window.rs
index b4a804464f5..d35dcd92ec7 100644
--- a/src/components/script/dom/window.rs
+++ b/src/components/script/dom/window.rs
@@ -72,7 +72,7 @@ pub struct TimerData {
 }
 
 impl Window {
-    pub fn Alert(&self, s: &DOMString) {
+    pub fn Alert(&self, s: &Option<DOMString>) {
         // Right now, just print to the console
         println(format!("ALERT: {:s}", null_str_as_empty(s)));
     }
@@ -85,18 +85,18 @@ impl Window {
         self.page.frame.unwrap().document
     }
 
-    pub fn Name(&self) -> DOMString {
+    pub fn Name(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetName(&self, _name: &DOMString) {
+    pub fn SetName(&self, _name: &Option<DOMString>) {
     }
 
-    pub fn Status(&self) -> DOMString {
+    pub fn Status(&self) -> Option<DOMString> {
         None
     }
 
-    pub fn SetStatus(&self, _status: &DOMString) {
+    pub fn SetStatus(&self, _status: &Option<DOMString>) {
     }
 
     pub fn Closed(&self) -> bool {
@@ -123,18 +123,18 @@ impl Window {
         self.navigator.unwrap()
     }
 
-    pub fn Confirm(&self, _message: &DOMString) -> bool {
+    pub fn Confirm(&self, _message: &Option<DOMString>) -> bool {
         false
     }
 
-    pub fn Prompt(&self, _message: &DOMString, _default: &DOMString) -> DOMString {
+    pub fn Prompt(&self, _message: &Option<DOMString>, _default: &Option<DOMString>) -> Option<DOMString> {
         None
     }
 
     pub fn Print(&self) {
     }
 
-    pub fn ShowModalDialog(&self, _cx: *JSContext, _url: &DOMString, _argument: JSVal) -> JSVal {
+    pub fn ShowModalDialog(&self, _cx: *JSContext, _url: &Option<DOMString>, _argument: JSVal) -> JSVal {
         JSVAL_NULL
     }
 }