Cargoify servo

components/script/dom/element.rs

@@ -0,0 +1,958 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+//! Element nodes.
+
+use dom::attr::{Attr, ReplacedAttr, FirstSetAttr, AttrHelpersForLayout};
+use dom::attr::{AttrValue, StringAttrValue, UIntAttrValue, AtomAttrValue};
+use dom::namednodemap::NamedNodeMap;
+use dom::bindings::codegen::Bindings::AttrBinding::AttrMethods;
+use dom::bindings::codegen::Bindings::ElementBinding;
+use dom::bindings::codegen::Bindings::ElementBinding::ElementMethods;
+use dom::bindings::codegen::InheritTypes::{ElementDerived, NodeCast};
+use dom::bindings::js::{JS, JSRef, Temporary, TemporaryPushable};
+use dom::bindings::js::{OptionalSettable, OptionalRootable, Root};
+use dom::bindings::trace::Traceable;
+use dom::bindings::utils::{Reflectable, Reflector};
+use dom::bindings::error::{ErrorResult, Fallible, NamespaceError, InvalidCharacter, Syntax};
+use dom::bindings::utils::{QName, Name, InvalidXMLName, xml_name_type};
+use dom::domrect::DOMRect;
+use dom::domrectlist::DOMRectList;
+use dom::document::{Document, DocumentHelpers};
+use dom::domtokenlist::DOMTokenList;
+use dom::eventtarget::{EventTarget, NodeTargetTypeId};
+use dom::htmlcollection::HTMLCollection;
+use dom::htmlserializer::serialize;
+use dom::node::{ElementNodeTypeId, Node, NodeHelpers, NodeIterator, document_from_node};
+use dom::node::{window_from_node, LayoutNodeHelpers};
+use dom::nodelist::NodeList;
+use dom::virtualmethods::{VirtualMethods, vtable_for};
+use layout_interface::ContentChangedDocumentDamage;
+use layout_interface::MatchSelectorsDocumentDamage;
+use style::{matches, parse_selector_list_from_str};
+use style;
+use servo_util::atom::Atom;
+use servo_util::namespace;
+use servo_util::namespace::{Namespace, Null};
+use servo_util::str::{DOMString, null_str_as_empty_ref};
+
+use std::ascii::StrAsciiExt;
+use std::cell::{Cell, RefCell};
+use std::mem;
+
+#[deriving(Encodable)]
+pub struct Element {
+    pub node: Node,
+    pub local_name: Atom,
+    pub namespace: Namespace,
+    pub prefix: Option<DOMString>,
+    pub attrs: RefCell<Vec<JS<Attr>>>,
+    pub style_attribute: Traceable<RefCell<Option<style::PropertyDeclarationBlock>>>,
+    pub attr_list: Cell<Option<JS<NamedNodeMap>>>,
+    class_list: Cell<Option<JS<DOMTokenList>>>,
+}
+
+impl ElementDerived for EventTarget {
+    fn is_element(&self) -> bool {
+        match self.type_id {
+            NodeTargetTypeId(ElementNodeTypeId(_)) => true,
+            _ => false
+        }
+    }
+}
+
+impl Reflectable for Element {
+    fn reflector<'a>(&'a self) -> &'a Reflector {
+        self.node.reflector()
+    }
+}
+
+#[deriving(PartialEq,Encodable)]
+pub enum ElementTypeId {
+    HTMLElementTypeId,
+    HTMLAnchorElementTypeId,
+    HTMLAppletElementTypeId,
+    HTMLAreaElementTypeId,
+    HTMLAudioElementTypeId,
+    HTMLBaseElementTypeId,
+    HTMLBRElementTypeId,
+    HTMLBodyElementTypeId,
+    HTMLButtonElementTypeId,
+    HTMLCanvasElementTypeId,
+    HTMLDataElementTypeId,
+    HTMLDataListElementTypeId,
+    HTMLDirectoryElementTypeId,
+    HTMLDListElementTypeId,
+    HTMLDivElementTypeId,
+    HTMLEmbedElementTypeId,
+    HTMLFieldSetElementTypeId,
+    HTMLFontElementTypeId,
+    HTMLFormElementTypeId,
+    HTMLFrameElementTypeId,
+    HTMLFrameSetElementTypeId,
+    HTMLHRElementTypeId,
+    HTMLHeadElementTypeId,
+    HTMLHeadingElementTypeId,
+    HTMLHtmlElementTypeId,
+    HTMLIFrameElementTypeId,
+    HTMLImageElementTypeId,
+    HTMLInputElementTypeId,
+    HTMLLabelElementTypeId,
+    HTMLLegendElementTypeId,
+    HTMLLinkElementTypeId,
+    HTMLLIElementTypeId,
+    HTMLMapElementTypeId,
+    HTMLMediaElementTypeId,
+    HTMLMetaElementTypeId,
+    HTMLMeterElementTypeId,
+    HTMLModElementTypeId,
+    HTMLObjectElementTypeId,
+    HTMLOListElementTypeId,
+    HTMLOptGroupElementTypeId,
+    HTMLOptionElementTypeId,
+    HTMLOutputElementTypeId,
+    HTMLParagraphElementTypeId,
+    HTMLParamElementTypeId,
+    HTMLPreElementTypeId,
+    HTMLProgressElementTypeId,
+    HTMLQuoteElementTypeId,
+    HTMLScriptElementTypeId,
+    HTMLSelectElementTypeId,
+    HTMLSourceElementTypeId,
+    HTMLSpanElementTypeId,
+    HTMLStyleElementTypeId,
+    HTMLTableElementTypeId,
+    HTMLTableCaptionElementTypeId,
+    HTMLTableDataCellElementTypeId,
+    HTMLTableHeaderCellElementTypeId,
+    HTMLTableColElementTypeId,
+    HTMLTableRowElementTypeId,
+    HTMLTableSectionElementTypeId,
+    HTMLTemplateElementTypeId,
+    HTMLTextAreaElementTypeId,
+    HTMLTimeElementTypeId,
+    HTMLTitleElementTypeId,
+    HTMLTrackElementTypeId,
+    HTMLUListElementTypeId,
+    HTMLVideoElementTypeId,
+    HTMLUnknownElementTypeId,
+
+    ElementTypeId,
+}
+
+//
+// Element methods
+//
+
+impl Element {
+    pub fn new_inherited(type_id: ElementTypeId, local_name: DOMString, namespace: Namespace, prefix: Option<DOMString>, document: &JSRef<Document>) -> Element {
+        Element {
+            node: Node::new_inherited(ElementNodeTypeId(type_id), document),
+            local_name: Atom::from_slice(local_name.as_slice()),
+            namespace: namespace,
+            prefix: prefix,
+            attrs: RefCell::new(vec!()),
+            attr_list: Cell::new(None),
+            class_list: Cell::new(None),
+            style_attribute: Traceable::new(RefCell::new(None)),
+        }
+    }
+
+    pub fn new(local_name: DOMString, namespace: Namespace, prefix: Option<DOMString>, document: &JSRef<Document>) -> Temporary<Element> {
+        let element = Element::new_inherited(ElementTypeId, local_name, namespace, prefix, document);
+        Node::reflect_node(box element, document, ElementBinding::Wrap)
+    }
+}
+
+pub trait RawLayoutElementHelpers {
+    unsafe fn get_attr_val_for_layout(&self, namespace: &Namespace, name: &str) -> Option<&'static str>;
+    unsafe fn get_attr_atom_for_layout(&self, namespace: &Namespace, name: &str) -> Option<Atom>;
+}
+
+impl RawLayoutElementHelpers for Element {
+    #[inline]
+    unsafe fn get_attr_val_for_layout(&self, namespace: &Namespace, name: &str)
+                                      -> Option<&'static str> {
+        // cast to point to T in RefCell<T> directly
+        let attrs: *const Vec<JS<Attr>> = mem::transmute(&self.attrs);
+        (*attrs).iter().find(|attr: & &JS<Attr>| {
+            let attr = attr.unsafe_get();
+            name == (*attr).local_name().as_slice() &&
+            (*attr).namespace == *namespace
+        }).map(|attr| {
+            let attr = attr.unsafe_get();
+            (*attr).value_ref_forever()
+        })
+    }
+
+    #[inline]
+    unsafe fn get_attr_atom_for_layout(&self, namespace: &Namespace, name: &str)
+                                      -> Option<Atom> {
+        // cast to point to T in RefCell<T> directly
+        let attrs: *const Vec<JS<Attr>> = mem::transmute(&self.attrs);
+        (*attrs).iter().find(|attr: & &JS<Attr>| {
+            let attr = attr.unsafe_get();
+            name == (*attr).local_name().as_slice() &&
+            (*attr).namespace == *namespace
+        }).and_then(|attr| {
+            let attr = attr.unsafe_get();
+            (*attr).value_atom_forever()
+        })
+    }
+}
+
+pub trait LayoutElementHelpers {
+    unsafe fn html_element_in_html_document_for_layout(&self) -> bool;
+}
+
+impl LayoutElementHelpers for JS<Element> {
+    unsafe fn html_element_in_html_document_for_layout(&self) -> bool {
+        if (*self.unsafe_get()).namespace != namespace::HTML {
+            return false
+        }
+        let node: JS<Node> = self.transmute_copy();
+        let owner_doc = node.owner_doc_for_layout().unsafe_get();
+        (*owner_doc).is_html_document
+    }
+}
+
+pub trait ElementHelpers {
+    fn html_element_in_html_document(&self) -> bool;
+    fn get_local_name<'a>(&'a self) -> &'a Atom;
+    fn get_namespace<'a>(&'a self) -> &'a Namespace;
+}
+
+impl<'a> ElementHelpers for JSRef<'a, Element> {
+    fn html_element_in_html_document(&self) -> bool {
+        let node: &JSRef<Node> = NodeCast::from_ref(self);
+        self.namespace == namespace::HTML && node.is_in_html_doc()
+    }
+
+    fn get_local_name<'a>(&'a self) -> &'a Atom {
+        &self.deref().local_name
+    }
+
+    fn get_namespace<'a>(&'a self) -> &'a Namespace {
+        &self.deref().namespace
+    }
+}
+
+pub trait AttributeHandlers {
+    fn get_attribute(&self, namespace: Namespace, name: &str) -> Option<Temporary<Attr>>;
+    fn set_attribute_from_parser(&self, local_name: Atom,
+                                 value: DOMString, namespace: Namespace,
+                                 prefix: Option<DOMString>);
+    fn set_attribute(&self, name: &str, value: AttrValue);
+    fn do_set_attribute(&self, local_name: Atom, value: AttrValue,
+                        name: Atom, namespace: Namespace,
+                        prefix: Option<DOMString>, cb: |&JSRef<Attr>| -> bool);
+    fn parse_attribute(&self, namespace: &Namespace, local_name: &Atom,
+                       value: DOMString) -> AttrValue;
+
+    fn remove_attribute(&self, namespace: Namespace, name: &str);
+    fn notify_attribute_changed(&self, local_name: &Atom);
+    fn has_class(&self, name: &str) -> bool;
+
+    fn set_atomic_attribute(&self, name: &str, value: DOMString);
+
+    // http://www.whatwg.org/html/#reflecting-content-attributes-in-idl-attributes
+    fn has_attribute(&self, name: &str) -> bool;
+    fn set_bool_attribute(&self, name: &str, value: bool);
+    fn get_url_attribute(&self, name: &str) -> DOMString;
+    fn set_url_attribute(&self, name: &str, value: DOMString);
+    fn get_string_attribute(&self, name: &str) -> DOMString;
+    fn set_string_attribute(&self, name: &str, value: DOMString);
+    fn set_tokenlist_attribute(&self, name: &str, value: DOMString);
+    fn get_uint_attribute(&self, name: &str) -> u32;
+    fn set_uint_attribute(&self, name: &str, value: u32);
+}
+
+impl<'a> AttributeHandlers for JSRef<'a, Element> {
+    fn get_attribute(&self, namespace: Namespace, name: &str) -> Option<Temporary<Attr>> {
+        let element: &Element = self.deref();
+        let local_name = match self.html_element_in_html_document() {
+            true => Atom::from_slice(name.to_ascii_lower().as_slice()),
+            false => Atom::from_slice(name)
+        };
+        element.attrs.borrow().iter().map(|attr| attr.root()).find(|attr| {
+            *attr.local_name() == local_name && attr.namespace == namespace
+        }).map(|x| Temporary::from_rooted(&*x))
+    }
+
+    fn set_attribute_from_parser(&self, local_name: Atom,
+                                 value: DOMString, namespace: Namespace,
+                                 prefix: Option<DOMString>) {
+        let name = match prefix {
+            None => local_name.clone(),
+            Some(ref prefix) => {
+                let name = format!("{:s}:{:s}", *prefix, local_name.as_slice());
+                Atom::from_slice(name.as_slice())
+            },
+        };
+        let value = self.parse_attribute(&namespace, &local_name, value);
+        self.do_set_attribute(local_name, value, name, namespace, prefix, |_| false)
+    }
+
+    fn set_attribute(&self, name: &str, value: AttrValue) {
+        assert!(name == name.to_ascii_lower().as_slice());
+        assert!(!name.contains(":"));
+
+        let node: &JSRef<Node> = NodeCast::from_ref(self);
+        node.wait_until_safe_to_modify_dom();
+
+        let name = Atom::from_slice(name);
+        self.do_set_attribute(name.clone(), value, name.clone(),
+            namespace::Null, None, |attr| *attr.local_name() == name);
+    }
+
+    fn do_set_attribute(&self, local_name: Atom, value: AttrValue,
+                        name: Atom, namespace: Namespace,
+                        prefix: Option<DOMString>, cb: |&JSRef<Attr>| -> bool) {
+        let idx = self.deref().attrs.borrow().iter()
+                                    .map(|attr| attr.root())
+                                    .position(|attr| cb(&*attr));
+        let (idx, set_type) = match idx {
+            Some(idx) => (idx, ReplacedAttr),
+            None => {
+                let window = window_from_node(self).root();
+                let attr = Attr::new(&*window, local_name, value.clone(),
+                                     name, namespace.clone(), prefix, self);
+                self.deref().attrs.borrow_mut().push_unrooted(&attr);
+                (self.deref().attrs.borrow().len() - 1, FirstSetAttr)
+            }
+        };
+
+        (*self.deref().attrs.borrow())[idx].root().set_value(set_type, value);
+    }
+
+    fn parse_attribute(&self, namespace: &Namespace, local_name: &Atom,
+                       value: DOMString) -> AttrValue {
+        if *namespace == namespace::Null {
+            vtable_for(NodeCast::from_ref(self))
+                .parse_plain_attribute(local_name.as_slice(), value)
+        } else {
+            StringAttrValue(value)
+        }
+    }
+
+    fn remove_attribute(&self, namespace: Namespace, name: &str) {
+        let (_, local_name) = get_attribute_parts(name);
+        let local_name = Atom::from_slice(local_name);
+
+        let idx = self.deref().attrs.borrow().iter().map(|attr| attr.root()).position(|attr| {
+            *attr.local_name() == local_name
+        });
+
+        match idx {
+            None => (),
+            Some(idx) => {
+                {
+                    let node: &JSRef<Node> = NodeCast::from_ref(self);
+                    node.wait_until_safe_to_modify_dom();
+                }
+
+                if namespace == namespace::Null {
+                    let removed_raw_value = (*self.deref().attrs.borrow())[idx].root().Value();
+                    vtable_for(NodeCast::from_ref(self))
+                        .before_remove_attr(&local_name,
+                                            removed_raw_value);
+                }
+
+                self.deref().attrs.borrow_mut().remove(idx);
+            }
+        };
+    }
+
+    fn notify_attribute_changed(&self, local_name: &Atom) {
+        let node: &JSRef<Node> = NodeCast::from_ref(self);
+        if node.is_in_doc() {
+            let damage = match local_name.as_slice() {
+                "style" | "id" | "class" => MatchSelectorsDocumentDamage,
+                _ => ContentChangedDocumentDamage
+            };
+            let document = node.owner_doc().root();
+            document.deref().damage_and_reflow(damage);
+        }
+    }
+
+    fn has_class(&self, name: &str) -> bool {
+        self.get_attribute(Null, "class").root().map(|attr| {
+            attr.deref().value().tokens().map(|mut tokens| {
+                tokens.any(|atom| atom.as_slice() == name)
+            }).unwrap_or(false)
+        }).unwrap_or(false)
+    }
+
+    fn set_atomic_attribute(&self, name: &str, value: DOMString) {
+        assert!(name == name.to_ascii_lower().as_slice());
+        let value = AttrValue::from_atomic(value);
+        self.set_attribute(name, value);
+    }
+
+    fn has_attribute(&self, name: &str) -> bool {
+        let name = match self.html_element_in_html_document() {
+            true => Atom::from_slice(name.to_ascii_lower().as_slice()),
+            false => Atom::from_slice(name)
+        };
+        self.deref().attrs.borrow().iter().map(|attr| attr.root()).any(|attr| {
+            *attr.local_name() == name && attr.namespace == Null
+        })
+    }
+
+    fn set_bool_attribute(&self, name: &str, value: bool) {
+        if self.has_attribute(name) == value { return; }
+        if value {
+            self.set_string_attribute(name, String::new());
+        } else {
+            self.remove_attribute(Null, name);
+        }
+    }
+
+    fn get_url_attribute(&self, name: &str) -> DOMString {
+        // XXX Resolve URL.
+        self.get_string_attribute(name)
+    }
+    fn set_url_attribute(&self, name: &str, value: DOMString) {
+        self.set_string_attribute(name, value);
+    }
+
+    fn get_string_attribute(&self, name: &str) -> DOMString {
+        match self.get_attribute(Null, name) {
+            Some(x) => {
+                let x = x.root();
+                x.deref().Value()
+            }
+            None => "".to_string()
+        }
+    }
+    fn set_string_attribute(&self, name: &str, value: DOMString) {
+        assert!(name == name.to_ascii_lower().as_slice());
+        self.set_attribute(name, StringAttrValue(value));
+    }
+
+    fn set_tokenlist_attribute(&self, name: &str, value: DOMString) {
+        assert!(name == name.to_ascii_lower().as_slice());
+        self.set_attribute(name, AttrValue::from_tokenlist(value));
+    }
+
+    fn get_uint_attribute(&self, name: &str) -> u32 {
+        assert!(name == name.to_ascii_lower().as_slice());
+        let attribute = self.get_attribute(Null, name).root();
+        match attribute {
+            Some(attribute) => {
+                match *attribute.deref().value() {
+                    UIntAttrValue(_, value) => value,
+                    _ => fail!("Expected a UIntAttrValue"),
+                }
+            }
+            None => 0,
+        }
+    }
+    fn set_uint_attribute(&self, name: &str, value: u32) {
+        assert!(name == name.to_ascii_lower().as_slice());
+        self.set_attribute(name, UIntAttrValue(value.to_string(), value));
+    }
+}
+
+impl Element {
+    pub fn is_void(&self) -> bool {
+        if self.namespace != namespace::HTML {
+            return false
+        }
+        match self.local_name.as_slice() {
+            /* List of void elements from
+            http://www.whatwg.org/specs/web-apps/current-work/multipage/the-end.html#html-fragment-serialization-algorithm */
+            "area" | "base" | "basefont" | "bgsound" | "br" | "col" | "embed" |
+            "frame" | "hr" | "img" | "input" | "keygen" | "link" | "menuitem" |
+            "meta" | "param" | "source" | "track" | "wbr" => true,
+            _ => false
+        }
+    }
+}
+
+impl<'a> ElementMethods for JSRef<'a, Element> {
+    // http://dom.spec.whatwg.org/#dom-element-namespaceuri
+    fn GetNamespaceURI(&self) -> Option<DOMString> {
+        match self.namespace {
+            Null => None,
+            ref ns => Some(ns.to_str().to_string())
+        }
+    }
+
+    fn LocalName(&self) -> DOMString {
+        self.local_name.as_slice().to_string()
+    }
+
+    // http://dom.spec.whatwg.org/#dom-element-prefix
+    fn GetPrefix(&self) -> Option<DOMString> {
+        self.prefix.clone()
+    }
+
+    // http://dom.spec.whatwg.org/#dom-element-tagname
+    fn TagName(&self) -> DOMString {
+        let qualified_name = match self.prefix {
+            Some(ref prefix) => format!("{}:{}", prefix, self.local_name).into_maybe_owned(),
+            None => self.local_name.as_slice().into_maybe_owned()
+        };
+        if self.html_element_in_html_document() {
+            qualified_name.as_slice().to_ascii_upper()
+        } else {
+            qualified_name.into_string()
+        }
+    }
+
+    // http://dom.spec.whatwg.org/#dom-element-id
+    fn Id(&self) -> DOMString {
+        self.get_string_attribute("id")
+    }
+
+    // http://dom.spec.whatwg.org/#dom-element-id
+    fn SetId(&self, id: DOMString) {
+        self.set_atomic_attribute("id", id);
+    }
+
+    // http://dom.spec.whatwg.org/#dom-element-classname
+    fn ClassName(&self) -> DOMString {
+        self.get_string_attribute("class")
+    }
+
+    // http://dom.spec.whatwg.org/#dom-element-classname
+    fn SetClassName(&self, class: DOMString) {
+        self.set_tokenlist_attribute("class", class);
+    }
+
+    // http://dom.spec.whatwg.org/#dom-element-classlist
+    fn ClassList(&self) -> Temporary<DOMTokenList> {
+        match self.class_list.get() {
+            Some(class_list) => Temporary::new(class_list),
+            None => {
+                let class_list = DOMTokenList::new(self, "class").root();
+                self.class_list.assign(Some(class_list.deref().clone()));
+                Temporary::from_rooted(&*class_list)
+            }
+        }
+    }
+
+    // http://dom.spec.whatwg.org/#dom-element-attributes
+    fn Attributes(&self) -> Temporary<NamedNodeMap> {
+        match self.attr_list.get() {
+            None => (),
+            Some(ref list) => return Temporary::new(list.clone()),
+        }
+
+        let doc = {
+            let node: &JSRef<Node> = NodeCast::from_ref(self);
+            node.owner_doc().root()
+        };
+        let window = doc.deref().window.root();
+        let list = NamedNodeMap::new(&*window, self);
+        self.attr_list.assign(Some(list));
+        Temporary::new(self.attr_list.get().get_ref().clone())
+    }
+
+    // http://dom.spec.whatwg.org/#dom-element-getattribute
+    fn GetAttribute(&self, name: DOMString) -> Option<DOMString> {
+        let name = if self.html_element_in_html_document() {
+            name.as_slice().to_ascii_lower()
+        } else {
+            name
+        };
+        self.get_attribute(Null, name.as_slice()).root()
+                     .map(|s| s.deref().Value())
+    }
+
+    // http://dom.spec.whatwg.org/#dom-element-getattributens
+    fn GetAttributeNS(&self,
+                      namespace: Option<DOMString>,
+                      local_name: DOMString) -> Option<DOMString> {
+        let namespace = Namespace::from_str(null_str_as_empty_ref(&namespace));
+        self.get_attribute(namespace, local_name.as_slice()).root()
+                     .map(|attr| attr.deref().Value())
+    }
+
+    // http://dom.spec.whatwg.org/#dom-element-setattribute
+    fn SetAttribute(&self,
+                    name: DOMString,
+                    value: DOMString) -> ErrorResult {
+        {
+            let node: &JSRef<Node> = NodeCast::from_ref(self);
+            node.wait_until_safe_to_modify_dom();
+        }
+
+        // Step 1.
+        match xml_name_type(name.as_slice()) {
+            InvalidXMLName => return Err(InvalidCharacter),
+            _ => {}
+        }
+
+        // Step 2.
+        let name = if self.html_element_in_html_document() {
+            name.as_slice().to_ascii_lower()
+        } else {
+            name
+        };
+
+        // Step 3-5.
+        let name = Atom::from_slice(name.as_slice());
+        let value = self.parse_attribute(&namespace::Null, &name, value);
+        self.do_set_attribute(name.clone(), value, name.clone(), namespace::Null, None, |attr| {
+            attr.deref().name.as_slice() == name.as_slice()
+        });
+        Ok(())
+    }
+
+    // http://dom.spec.whatwg.org/#dom-element-setattributens
+    fn SetAttributeNS(&self,
+                      namespace_url: Option<DOMString>,
+                      name: DOMString,
+                      value: DOMString) -> ErrorResult {
+        {
+            let node: &JSRef<Node> = NodeCast::from_ref(self);
+            node.wait_until_safe_to_modify_dom();
+        }
+
+        // Step 1.
+        let namespace = Namespace::from_str(null_str_as_empty_ref(&namespace_url));
+
+        let name_type = xml_name_type(name.as_slice());
+        match name_type {
+            // Step 2.
+            InvalidXMLName => return Err(InvalidCharacter),
+            // Step 3.
+            Name => return Err(NamespaceError),
+            QName => {}
+        }
+
+        // Step 4.
+        let (prefix, local_name) = get_attribute_parts(name.as_slice());
+        match prefix {
+            Some(ref prefix_str) => {
+                // Step 5.
+                if namespace == namespace::Null {
+                    return Err(NamespaceError);
+                }
+
+                // Step 6.
+                if "xml" == prefix_str.as_slice() && namespace != namespace::XML {
+                    return Err(NamespaceError);
+                }
+
+                // Step 7b.
+                if "xmlns" == prefix_str.as_slice() && namespace != namespace::XMLNS {
+                    return Err(NamespaceError);
+                }
+            },
+            None => {}
+        }
+
+        let name = Atom::from_slice(name.as_slice());
+        let local_name = Atom::from_slice(local_name);
+        let xmlns = Atom::from_slice("xmlns");      // TODO: Make this a static atom type
+
+        // Step 7a.
+        if xmlns == name && namespace != namespace::XMLNS {
+            return Err(NamespaceError);
+        }
+
+        // Step 8.
+        if namespace == namespace::XMLNS && xmlns != name && Some("xmlns") != prefix {
+            return Err(NamespaceError);
+        }
+
+        // Step 9.
+        let value = self.parse_attribute(&namespace, &local_name, value);
+        self.do_set_attribute(local_name.clone(), value, name,
+                              namespace.clone(), prefix.map(|s| s.to_string()),
+                              |attr| {
+            *attr.local_name() == local_name &&
+            attr.namespace == namespace
+        });
+        Ok(())
+    }
+
+    // http://dom.spec.whatwg.org/#dom-element-removeattribute
+    fn RemoveAttribute(&self, name: DOMString) {
+        let name = if self.html_element_in_html_document() {
+            name.as_slice().to_ascii_lower()
+        } else {
+            name
+        };
+        self.remove_attribute(namespace::Null, name.as_slice())
+    }
+
+    // http://dom.spec.whatwg.org/#dom-element-removeattributens
+    fn RemoveAttributeNS(&self,
+                         namespace: Option<DOMString>,
+                         localname: DOMString) {
+        let namespace = Namespace::from_str(null_str_as_empty_ref(&namespace));
+        self.remove_attribute(namespace, localname.as_slice())
+    }
+
+    // http://dom.spec.whatwg.org/#dom-element-hasattribute
+    fn HasAttribute(&self,
+                    name: DOMString) -> bool {
+        self.has_attribute(name.as_slice())
+    }
+
+    // http://dom.spec.whatwg.org/#dom-element-hasattributens
+    fn HasAttributeNS(&self,
+                      namespace: Option<DOMString>,
+                      local_name: DOMString) -> bool {
+        self.GetAttributeNS(namespace, local_name).is_some()
+    }
+
+    fn GetElementsByTagName(&self, localname: DOMString) -> Temporary<HTMLCollection> {
+        let window = window_from_node(self).root();
+        HTMLCollection::by_tag_name(&*window, NodeCast::from_ref(self), localname)
+    }
+
+    fn GetElementsByTagNameNS(&self, maybe_ns: Option<DOMString>,
+                              localname: DOMString) -> Temporary<HTMLCollection> {
+        let window = window_from_node(self).root();
+        HTMLCollection::by_tag_name_ns(&*window, NodeCast::from_ref(self), localname, maybe_ns)
+    }
+
+    fn GetElementsByClassName(&self, classes: DOMString) -> Temporary<HTMLCollection> {
+        let window = window_from_node(self).root();
+        HTMLCollection::by_class_name(&*window, NodeCast::from_ref(self), classes)
+    }
+
+    // http://dev.w3.org/csswg/cssom-view/#dom-element-getclientrects
+    fn GetClientRects(&self) -> Temporary<DOMRectList> {
+        let win = window_from_node(self).root();
+        let node: &JSRef<Node> = NodeCast::from_ref(self);
+        let rects = node.get_content_boxes();
+        let rects: Vec<Root<DOMRect>> = rects.iter().map(|r| {
+            DOMRect::new(
+                &*win,
+                r.origin.y,
+                r.origin.y + r.size.height,
+                r.origin.x,
+                r.origin.x + r.size.width).root()
+        }).collect();
+
+        DOMRectList::new(&*win, rects.iter().map(|rect| rect.deref().clone()).collect())
+    }
+
+    // http://dev.w3.org/csswg/cssom-view/#dom-element-getboundingclientrect
+    fn GetBoundingClientRect(&self) -> Temporary<DOMRect> {
+        let win = window_from_node(self).root();
+        let node: &JSRef<Node> = NodeCast::from_ref(self);
+        let rect = node.get_bounding_content_box();
+        DOMRect::new(
+            &*win,
+            rect.origin.y,
+            rect.origin.y + rect.size.height,
+            rect.origin.x,
+            rect.origin.x + rect.size.width)
+    }
+
+    fn GetInnerHTML(&self) -> Fallible<DOMString> {
+        //XXX TODO: XML case
+        Ok(serialize(&mut NodeIterator::new(NodeCast::from_ref(self), false, false)))
+    }
+
+    fn GetOuterHTML(&self) -> Fallible<DOMString> {
+        Ok(serialize(&mut NodeIterator::new(NodeCast::from_ref(self), true, false)))
+    }
+
+    // http://dom.spec.whatwg.org/#dom-parentnode-children
+    fn Children(&self) -> Temporary<HTMLCollection> {
+        let window = window_from_node(self).root();
+        HTMLCollection::children(&*window, NodeCast::from_ref(self))
+    }
+
+    // http://dom.spec.whatwg.org/#dom-parentnode-queryselector
+    fn QuerySelector(&self, selectors: DOMString) -> Fallible<Option<Temporary<Element>>> {
+        let root: &JSRef<Node> = NodeCast::from_ref(self);
+        root.query_selector(selectors)
+    }
+
+    // http://dom.spec.whatwg.org/#dom-parentnode-queryselectorall
+    fn QuerySelectorAll(&self, selectors: DOMString) -> Fallible<Temporary<NodeList>> {
+        let root: &JSRef<Node> = NodeCast::from_ref(self);
+        root.query_selector_all(selectors)
+    }
+
+    // http://dom.spec.whatwg.org/#dom-childnode-remove
+    fn Remove(&self) {
+        let node: &JSRef<Node> = NodeCast::from_ref(self);
+        node.remove_self();
+    }
+
+    // http://dom.spec.whatwg.org/#dom-element-matches
+    fn Matches(&self, selectors: DOMString) -> Fallible<bool> {
+        match parse_selector_list_from_str(selectors.as_slice()) {
+            Err(()) => Err(Syntax),
+            Ok(ref selectors) => {
+                let root: &JSRef<Node> = NodeCast::from_ref(self);
+                Ok(matches(selectors, root))
+            }
+        }
+    }
+}
+
+pub fn get_attribute_parts<'a>(name: &'a str) -> (Option<&'a str>, &'a str) {
+    //FIXME: Throw for XML-invalid names
+    //FIXME: Throw for XMLNS-invalid names
+    let (prefix, local_name) = if name.contains(":")  {
+        let mut parts = name.splitn(':', 1);
+        (Some(parts.next().unwrap()), parts.next().unwrap())
+    } else {
+        (None, name)
+    };
+
+    (prefix, local_name)
+}
+
+impl<'a> VirtualMethods for JSRef<'a, Element> {
+    fn super_type<'a>(&'a self) -> Option<&'a VirtualMethods> {
+        let node: &JSRef<Node> = NodeCast::from_ref(self);
+        Some(node as &VirtualMethods)
+    }
+
+    fn after_set_attr(&self, name: &Atom, value: DOMString) {
+        match self.super_type() {
+            Some(ref s) => s.after_set_attr(name, value.clone()),
+            _ => (),
+        }
+
+        match name.as_slice() {
+            "style" => {
+                let doc = document_from_node(self).root();
+                let base_url = doc.deref().url().clone();
+                let style = Some(style::parse_style_attribute(value.as_slice(), &base_url));
+                *self.deref().style_attribute.deref().borrow_mut() = style;
+            }
+            "id" => {
+                let node: &JSRef<Node> = NodeCast::from_ref(self);
+                if node.is_in_doc() && !value.is_empty() {
+                    let doc = document_from_node(self).root();
+                    doc.register_named_element(self, value.clone());
+                }
+            }
+            _ => ()
+        }
+
+        self.notify_attribute_changed(name);
+    }
+
+    fn before_remove_attr(&self, name: &Atom, value: DOMString) {
+        match self.super_type() {
+            Some(ref s) => s.before_remove_attr(name, value.clone()),
+            _ => (),
+        }
+
+        match name.as_slice() {
+            "style" => {
+                *self.deref().style_attribute.deref().borrow_mut() = None;
+            }
+            "id" => {
+                let node: &JSRef<Node> = NodeCast::from_ref(self);
+                if node.is_in_doc() && !value.is_empty() {
+                    let doc = document_from_node(self).root();
+                    doc.unregister_named_element(self, value);
+                }
+            }
+            _ => ()
+        }
+
+        self.notify_attribute_changed(name);
+    }
+
+    fn parse_plain_attribute(&self, name: &str, value: DOMString) -> AttrValue {
+        match name {
+            "id" => AttrValue::from_atomic(value),
+            "class" => AttrValue::from_tokenlist(value),
+            _ => self.super_type().unwrap().parse_plain_attribute(name, value),
+        }
+    }
+
+    fn bind_to_tree(&self, tree_in_doc: bool) {
+        match self.super_type() {
+            Some(ref s) => s.bind_to_tree(tree_in_doc),
+            _ => (),
+        }
+
+        if !tree_in_doc { return; }
+
+        match self.get_attribute(Null, "id").root() {
+            Some(attr) => {
+                let doc = document_from_node(self).root();
+                let value = attr.deref().Value();
+                if !value.is_empty() {
+                    doc.deref().register_named_element(self, value);
+                }
+            }
+            _ => ()
+        }
+    }
+
+    fn unbind_from_tree(&self, tree_in_doc: bool) {
+        match self.super_type() {
+            Some(ref s) => s.unbind_from_tree(tree_in_doc),
+            _ => (),
+        }
+
+        if !tree_in_doc { return; }
+
+        match self.get_attribute(Null, "id").root() {
+            Some(attr) => {
+                let doc = document_from_node(self).root();
+                let value = attr.deref().Value();
+                if !value.is_empty() {
+                    doc.deref().unregister_named_element(self, value);
+                }
+            }
+            _ => ()
+        }
+    }
+}
+
+impl<'a> style::TElement for JSRef<'a, Element> {
+    fn get_attr(&self, namespace: &Namespace, attr: &str) -> Option<&'static str> {
+        self.get_attribute(namespace.clone(), attr).root().map(|attr| {
+            unsafe { mem::transmute(attr.deref().value().as_slice()) }
+        })
+    }
+    fn get_link(&self) -> Option<&'static str> {
+        // FIXME: This is HTML only.
+        let node: &JSRef<Node> = NodeCast::from_ref(self);
+        match node.type_id() {
+            // http://www.whatwg.org/specs/web-apps/current-work/multipage/selectors.html#
+            // selector-link
+            ElementNodeTypeId(HTMLAnchorElementTypeId) |
+            ElementNodeTypeId(HTMLAreaElementTypeId) |
+            ElementNodeTypeId(HTMLLinkElementTypeId) => self.get_attr(&namespace::Null, "href"),
+            _ => None,
+         }
+    }
+    fn get_local_name<'a>(&'a self) -> &'a Atom {
+        (self as &ElementHelpers).get_local_name()
+    }
+    fn get_namespace<'a>(&'a self) -> &'a Namespace {
+        (self as &ElementHelpers).get_namespace()
+    }
+    fn get_hover_state(&self) -> bool {
+        let node: &JSRef<Node> = NodeCast::from_ref(self);
+        node.get_hover_state()
+    }
+    fn get_id<'a>(&self) -> Option<Atom> {
+        self.get_attribute(namespace::Null, "id").map(|attr| {
+            let attr = attr.root();
+            match *attr.value() {
+                AtomAttrValue(ref val) => val.clone(),
+                _ => fail!("`id` attribute should be AtomAttrValue"),
+            }
+        })
+    }
+    fn get_disabled_state(&self) -> bool {
+        let node: &JSRef<Node> = NodeCast::from_ref(self);
+        node.get_disabled_state()
+    }
+    fn get_enabled_state(&self) -> bool {
+        let node: &JSRef<Node> = NodeCast::from_ref(self);
+        node.get_enabled_state()
+    }
+}