Add basic binding for HTMLCollection.

14 files changed, 280 insertions, 93 deletions

diff --git a/src/servo/dom/bindings/codegen/Bindings.conf b/src/servo/dom/bindings/codegen/Bindings.conf
index fcca574d510..8bfc300ca49 100644
--- a/src/servo/dom/bindings/codegen/Bindings.conf
+++ b/src/servo/dom/bindings/codegen/Bindings.conf
@@ -212,9 +212,9 @@ DOMInterfaces = {
 
 'HTMLCollection': [
 {
-    'nativeType': 'nsIHTMLCollection',
-    'prefable': True,
-    'resultNotAddRefed': [ 'item' ]
+    'nativeType': 'HTMLCollection',
+    #'prefable': True,
+    #'resultNotAddRefed': [ 'item' ]
 }],
 
 'HTMLOptionsCollection': [
@@ -490,7 +490,7 @@ DOMInterfaces = {
 }
 
 # These are temporary, until they've been converted to use new DOM bindings
-def addExternalIface(iface, nativeType=None, headerFile=None):
+def addExternalIface(iface, nativeType=None, headerFile=None, pointerType=None):
     domInterface = {
         'concrete': False
     }
@@ -498,6 +498,8 @@ def addExternalIface(iface, nativeType=None, headerFile=None):
         domInterface['nativeType'] = nativeType
     if not headerFile is None:
         domInterface['headerFile'] = headerFile
+    if not pointerType is None:
+        domInterface['pointerType'] = pointerType
     DOMInterfaces[iface] = domInterface
 
 # If you add one of these, you need to make sure nsDOMQS.h has the relevant
@@ -519,7 +521,7 @@ addExternalIface('CSSRule')
 addExternalIface('CSSValue')
 addExternalIface('DOMStringList', nativeType='nsDOMStringList',
                  headerFile='nsDOMLists.h')
-addExternalIface('Element', nativeType='nsGenericElement')
+addExternalIface('Element', nativeType='AbstractNode', pointerType='')
 addExternalIface('File')
 addExternalIface('HitRegionOptions', nativeType='nsISupports')
 addExternalIface('HTMLElement')
diff --git a/src/servo/dom/bindings/codegen/CodegenRust.py b/src/servo/dom/bindings/codegen/CodegenRust.py
index e35be6e3148..4421023bec8 100644
--- a/src/servo/dom/bindings/codegen/CodegenRust.py
+++ b/src/servo/dom/bindings/codegen/CodegenRust.py
@@ -1041,10 +1041,16 @@ for (uint32_t i = 0; i < length; ++i) {
         undefinedBehavior = treatAs[treatUndefinedAs]
 
         def getConversionCode(varName):
+            #conversionCode = (
+            #    "if (!ConvertJSValueToString(cx, ${val}, ${valPtr}, %s, %s, %s)) {\n"
+            #    "  return false;\n"
+            #    "}" % (nullBehavior, undefinedBehavior, varName))
             conversionCode = (
-                "if (!ConvertJSValueToString(cx, ${val}, ${valPtr}, %s, %s, %s)) {\n"
-                "  return false;\n"
-                "}" % (nullBehavior, undefinedBehavior, varName))
+                "let strval = jsval_to_str(cx, ${val});\n"
+                "if strval.is_err() {\n"
+                "  return 0;\n"
+                "}\n"
+                "%s = str(strval.get());" % varName)
             if defaultValue is None:
                 return conversionCode
 
@@ -1072,15 +1078,15 @@ for (uint32_t i = 0; i < length; ++i) {
                 declType, None, isOptional)
 
         if isOptional:
-            declType = "Optional<nsAString>"
+            declType = "Option<DOMString>"
         else:
-            declType = "NonNull<nsAString>"
+            declType = "DOMString"
 
         return (
-            "%s\n"
-            "const_cast<%s&>(${declName}) = &${holderName};" %
-            (getConversionCode("${holderName}"), declType),
-            CGGeneric("const " + declType), CGGeneric("FakeDependentString"),
+            "%s\n" %
+            #"const_cast<%s&>(${declName}) = &${holderName};" %
+            (getConversionCode("${declName}")),
+            CGGeneric(declType), None, #CGGeneric("FakeDependentString"),
             # No need to deal with Optional here; we have handled it already
             False)
 
@@ -1441,7 +1447,7 @@ def getWrapTemplateForType(type, descriptorProvider, result, successCode,
                     "}\n" +
                     successCode)
         else:
-            tail = "return JS_WrapValue(cx, ${jsvalPtr});"
+            tail = "return JS_WrapValue(cx, cast::transmute(${jsvalPtr}));"
         return ("${jsvalRef} = %s;\n" +
                 tail) % (value)
 
@@ -1511,7 +1517,8 @@ for (uint32_t i = 0; i < length; ++i) {
         if type.nullable():
             wrappingCode = ("if %s.is_none() {\n" % (result) +
                             CGIndenter(CGGeneric(setValue("JSVAL_NULL"))).define() + "\n" +
-                            "}\n")
+                            "}\n" +
+                            "let mut %s = %s.get();\n" % (result, result))
         else:
             wrappingCode = ""
         if (not descriptor.interface.isExternal() and
@@ -1522,7 +1529,7 @@ for (uint32_t i = 0; i < length; ++i) {
                 if not isCreator:
                     raise MethodNotCreatorError(descriptor.interface.identifier.name)
                 wrapMethod = "WrapNewBindingNonWrapperCachedObject"
-            wrap = "%s(cx, ${obj}, %s.get(), ${jsvalPtr})" % (wrapMethod, result)
+            wrap = "%s(cx, ${obj}, %s, ${jsvalPtr})" % (wrapMethod, result)
             # We don't support prefable stuff in workers.
             assert(not descriptor.prefable or not descriptor.workers)
             if not descriptor.prefable:
@@ -1544,7 +1551,8 @@ for (uint32_t i = 0; i < length; ++i) {
                 getIID = "&NS_GET_IID(%s), " % descriptor.nativeType
             else:
                 getIID = ""
-            wrap = "WrapObject(cx, ${obj}, %s, %s${jsvalPtr})" % (result, getIID)
+            #wrap = "WrapObject(cx, ${obj}, %s, %s${jsvalPtr})" % (result, getIID)
+            wrap = "%s.wrap(cx, ${obj}, %s${jsvalPtr})" % (result, getIID)
             wrappingCode += wrapAndSetPtr(wrap)
         return (wrappingCode, False)
 
@@ -1587,7 +1595,7 @@ if (!%(resultStr)s) {
         # See comments in WrapNewBindingObject explaining why we need
         # to wrap here.
         if type.nullable():
-            toValue = "JS::ObjectOrNullValue(%s)"
+            toValue = "RUST_OBJECT_TO_JSVAL(%s)"
         else:
             toValue = "JS::ObjectValue(*%s)"
         # NB: setValue(..., True) calls JS_WrapValue(), so is fallible
@@ -1690,10 +1698,11 @@ def getRetvalDeclarationForType(returnType, descriptorProvider,
             raise TypeError("We don't support nullable enum return values")
         return CGGeneric(returnType.inner.identifier.name), False
     if returnType.isGeckoInterface():
-        result = CGGeneric(descriptorProvider.getDescriptor(
-            returnType.unroll().inner.identifier.name).nativeType)
+        descriptor = descriptorProvider.getDescriptor(
+            returnType.unroll().inner.identifier.name)
+        result = CGGeneric(descriptor.nativeType)
         if resultAlreadyAddRefed:
-            result = CGWrapper(result, pre="Option<~", post=">")
+            result = CGWrapper(result, pre=("Option<" + descriptor.pointerType), post=">")
         else:
             result = CGWrapper(result, post="*")
         return result, False
@@ -2901,7 +2910,7 @@ class CGCallGenerator(CGThing):
         if resultOutParam:
             args.append(CGGeneric("result"))
         if isFallible:
-            args.append(CGGeneric("rv"))
+            args.append(CGGeneric("&mut rv"))
 
         needsCx = (typeNeedsCx(returnType, True) or
                    any(typeNeedsCx(a.type) for (a, _) in arguments) or
@@ -2930,8 +2939,8 @@ class CGCallGenerator(CGThing):
         self.cgRoot.append(call)
 
         if isFallible:
-            self.cgRoot.prepend(CGGeneric("ErrorResult rv;"))
-            self.cgRoot.append(CGGeneric("if (rv.Failed()) {"))
+            self.cgRoot.prepend(CGGeneric("let mut rv: ErrorResult = Ok(());"))
+            self.cgRoot.append(CGGeneric("if (rv.is_err()) {"))
             self.cgRoot.append(CGIndenter(errorReport))
             self.cgRoot.append(CGGeneric("}"))
 
@@ -3031,10 +3040,11 @@ class CGPerSignatureCall(CGThing):
                              self.idlNode.identifier.name))
 
     def getErrorReport(self):
-        return CGGeneric('return ThrowMethodFailedWithDetails<%s>(cx, rv, "%s", "%s");'
-                         % (toStringBool(not self.descriptor.workers),
-                            self.descriptor.interface.identifier.name,
-                            self.idlNode.identifier.name))
+        #return CGGeneric('return ThrowMethodFailedWithDetails<%s>(cx, rv, "%s", "%s");'
+        #                 % (toStringBool(not self.descriptor.workers),
+        #                    self.descriptor.interface.identifier.name,
+        #                    self.idlNode.identifier.name))
+        return CGGeneric('return 0'); #XXXjdm
 
     def define(self):
         return (self.cgRoot.define() + "\n" + self.wrap_return_value())
@@ -3844,10 +3854,12 @@ class CGBindingRoot(CGThing):
                           'js::jsfriendapi::bindgen::*',
                           'js::glue::bindgen::*',
                           'js::glue::*',
+                          'dom::node::AbstractNode',
                           'dom::bindings::utils::*',
                           'dom::bindings::conversions::*',
                           'dom::bindings::clientrect::*', #XXXjdm
                           'dom::bindings::clientrectlist::*', #XXXjdm
+                          'dom::bindings::htmlcollection::*', #XXXjdm
                           'dom::bindings::proxyhandler::*',
                           'content::content_task::task_from_context'
                          ], 
diff --git a/src/servo/dom/bindings/codegen/Configuration.py b/src/servo/dom/bindings/codegen/Configuration.py
index 9f0c20f6584..d1ca528a3a3 100644
--- a/src/servo/dom/bindings/codegen/Configuration.py
+++ b/src/servo/dom/bindings/codegen/Configuration.py
@@ -139,7 +139,7 @@ class Descriptor(DescriptorProvider):
                 nativeTypeDefault = "mozilla::dom::" + ifaceName
 
         self.nativeType = desc.get('nativeType', nativeTypeDefault)
-        self.pointerType = desc.get('pointerType', '@')
+        self.pointerType = desc.get('pointerType', '~')
         self.hasInstanceInterface = desc.get('hasInstanceInterface', None)
 
         # Do something sane for JSObject
diff --git a/src/servo/dom/bindings/codegen/HTMLCollection.webidl b/src/servo/dom/bindings/codegen/HTMLCollection.webidl
new file mode 100644
index 00000000000..5797f85e392
--- /dev/null
+++ b/src/servo/dom/bindings/codegen/HTMLCollection.webidl
@@ -0,0 +1,20 @@
+/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/.
+ *
+ * The origin of this IDL file is
+ * http://www.w3.org/TR/2012/WD-dom-20120105/
+ *
+ * Copyright © 2012 W3C® (MIT, ERCIM, Keio), All Rights Reserved. W3C
+ * liability, trademark and document use rules apply.
+ */
+
+interface Element;
+
+interface HTMLCollection {
+  readonly attribute unsigned long length;
+  getter Element? item(unsigned long index);
+  [Throws]
+  getter object? namedItem(DOMString name); // only returns Element
+};
diff --git a/src/servo/dom/bindings/codegen/RegisterBindings.cpp b/src/servo/dom/bindings/codegen/RegisterBindings.cpp
index 12e20c201d3..0cc45d1ddc4 100644
--- a/src/servo/dom/bindings/codegen/RegisterBindings.cpp
+++ b/src/servo/dom/bindings/codegen/RegisterBindings.cpp
@@ -1,5 +1,6 @@
 #include "ClientRectBinding.h"
 #include "ClientRectListBinding.h"
+#include "HTMLCollectionBinding.h"
 #include "nsScriptNameSpaceManager.h"
 
 namespace mozilla {
@@ -13,6 +14,7 @@ Register(nsScriptNameSpaceManager* aNameSpaceManager)
 
 REGISTER_PROTO(ClientRect, nullptr);
 REGISTER_PROTO(ClientRectList, nullptr);
+REGISTER_PROTO(HTMLCollection, nullptr);
 
 #undef REGISTER_PROTO
 }
diff --git a/src/servo/dom/bindings/document.rs b/src/servo/dom/bindings/document.rs
index 8c8df125c61..6879db9c837 100644
--- a/src/servo/dom/bindings/document.rs
+++ b/src/servo/dom/bindings/document.rs
@@ -2,7 +2,8 @@ use js::rust::{Compartment, jsobj};
 use js::{JS_ARGV, JSCLASS_HAS_RESERVED_SLOTS, JSPROP_ENUMERATE, JSPROP_SHARED,
             JSVAL_NULL, JS_THIS_OBJECT, JS_SET_RVAL, JSPROP_NATIVE_ACCESSORS};
 use js::jsapi::{JSContext, JSVal, JSObject, JSBool, jsid, JSClass, JSFreeOp,
-                JSPropertySpec, JSPropertyOpWrapper, JSStrictPropertyOpWrapper};
+                JSPropertySpec, JSPropertyOpWrapper, JSStrictPropertyOpWrapper,
+                JSNativeWrapper, JSFunctionSpec};
 use js::jsapi::bindgen::{JS_ValueToString, JS_GetStringCharsZAndLength, JS_ReportError,
                             JS_GetReservedSlot, JS_SetReservedSlot, JS_NewStringCopyN,
                             JS_DefineFunctions, JS_DefineProperty, JS_DefineProperties};
@@ -12,67 +13,53 @@ use js::crust::{JS_PropertyStub, JS_StrictPropertyStub, JS_EnumerateStub, JS_Con
 use core::ptr::null;
 use core::libc::c_uint;
 use dom::bindings::utils::{DOMString, domstring_to_jsval, rust_box, squirrel_away, str};
+use dom::bindings::utils::{jsval_to_str, WrapNewBindingObject, CacheableWrapper};
+use dom::bindings::utils::WrapperCache;
 use dom::bindings::node::create;
 
 use dom::document::Document;
+use dom::bindings::htmlcollection::HTMLCollection;
 use dom::bindings::node;
 use dom::bindings::utils;
 use dom::node::Node;
 
-enum DOMException {
-    INVALID_CHARACTER_ERR
-}
-
-struct Element(int);
-
-/*extern fn getElementById(cx: *JSContext, argc: c_uint, vp: *jsval) -> JSBool {
-    //XXX check if actually document object
-    if argc != 1 {
-        //XXX throw proper DOM exception
-        str::as_c_str("Not enough arguments", |s| {
-            JS_ReportError(cx, s);
-        });
-        return 0;
-    }
-    let id;
+extern fn getDocumentElement(cx: *JSContext, _argc: c_uint, vp: *mut JSVal) -> JSBool {
     unsafe {
-        id = JS_ARGV(cx, vp)[0];
-    }
-    alt jsval_to_str(cx, id) {
-      ok(s) {
-        unsafe {
-            let doc: *Document = cast::reinterpret_cast(JS_GetContextPrivate(cx));
-            let elem = (*doc).getElementById(s);
+        let obj = JS_THIS_OBJECT(cx, cast::reinterpret_cast(&vp));
+        if obj.is_null() {
+            return 0;
         }
-        //XXX wrap result
+
+        let doc = &mut (*unwrap(obj)).payload;
+        *vp = RUST_OBJECT_TO_JSVAL(node::create(cx, &mut doc.root).ptr);
         return 1;
-      }
-      err(_) {
-        str::as_c_str("???", |s| {
-            JS_ReportError(cx, s);
-        });
-        return 0;
-      }
     }
-}*/
+}
 
-/*extern fn getDocumentURI(cx: *JSContext, _argc: c_uint, vp: *jsval) -> JSBool {
+extern fn getElementsByTagName(cx: *JSContext, argc: c_uint, vp: *JSVal) -> JSBool {
     unsafe {
-        let uri = (*unwrap(JS_THIS_OBJECT(cx, vp))).payload.getDocumentURI();
-        JS_SET_RVAL(cx, vp, domstring_to_jsval(cx, uri));
-    }
-    return 1;
-}*/
+        let obj = JS_THIS_OBJECT(cx, vp);
 
-extern fn getDocumentElement(cx: *JSContext, _argc: c_uint, vp: *mut JSVal) -> JSBool {
-    unsafe {
-        let obj = JS_THIS_OBJECT(cx, cast::reinterpret_cast(&vp));
-        if obj.is_null() {
+        let argv = JS_ARGV(cx, cast::transmute(vp));
+
+        let arg0: DOMString;
+        let strval = jsval_to_str(cx, (*argv.offset(0)));
+        if strval.is_err() {
             return 0;
         }
+        arg0 = str(strval.get());
 
         let doc = &mut (*unwrap(obj)).payload;
-        *vp = RUST_OBJECT_TO_JSVAL(node::create(cx, &mut doc.root).ptr);
+        let rval: Option<~HTMLCollection>;
+        rval = doc.getElementsByTagName(arg0);
+        if rval.is_none() {
+            JS_SET_RVAL(cx, vp, JSVAL_NULL);
+        } else {
+            let cache = doc.get_wrappercache();
+            fail_unless!(WrapNewBindingObject(cx, cache.get_wrapper(),
+                                              rval.get(),
+                                              cast::transmute(vp)));
+        }
         return 1;
     }
 }
@@ -112,11 +99,26 @@ pub fn init(compartment: @mut Compartment, doc: @mut Document) {
         fail_unless!(JS_DefineProperties(compartment.cx.ptr, obj.ptr, specs) == 1);
     });
 
+    let methods = @~[JSFunctionSpec {name: compartment.add_name(~"getElementsByTagName"),
+                                     call: JSNativeWrapper {op: getElementsByTagName, info: null()},
+                                     nargs: 0,
+                                     flags: 0,
+                                     selfHostedName: null()},
+                     JSFunctionSpec {name: null(),
+                                     call: JSNativeWrapper {op: null(), info: null()},
+                                     nargs: 0,
+                                     flags: 0,
+                                     selfHostedName: null()}];
+    vec::as_imm_buf(*methods, |fns, _len| {
+        JS_DefineFunctions(compartment.cx.ptr, obj.ptr, fns);
+    });
+
     compartment.register_class(utils::instance_jsclass(~"DocumentInstance", finalize));
 
     let instance : jsobj = result::unwrap(
         compartment.new_object_with_proto(~"DocumentInstance", ~"Document",
                                           compartment.global_obj.ptr));
+    doc.wrapper.set_wrapper(instance.ptr);
 
     unsafe {
         let raw_ptr: *libc::c_void = cast::reinterpret_cast(&squirrel_away(doc));
@@ -128,3 +130,17 @@ pub fn init(compartment: @mut Compartment, doc: @mut Document) {
                                 GetJSClassHookStubPointer(STRICT_PROPERTY_STUB) as *u8,
                                 JSPROP_ENUMERATE);
 }
+
+impl CacheableWrapper for Document {
+    fn get_wrappercache(&mut self) -> &mut WrapperCache {
+        unsafe { cast::transmute(&self.wrapper) }
+    }
+
+    fn wrap_object_unique(~self, cx: *JSContext, scope: *JSObject) -> *JSObject {
+        fail!(~"need to implement wrapping");
+    }
+
+    fn wrap_object_shared(@self, cx: *JSContext, scope: *JSObject) -> *JSObject {
+        fail!(~"need to implement wrapping");
+    }
+}
diff --git a/src/servo/dom/bindings/element.rs b/src/servo/dom/bindings/element.rs
index ba2c139003a..da3b2e4d440 100644
--- a/src/servo/dom/bindings/element.rs
+++ b/src/servo/dom/bindings/element.rs
@@ -2,7 +2,6 @@ use content::content_task::{Content, task_from_context};
 use dom::bindings::utils::{rust_box, squirrel_away_unique, get_compartment};
 use dom::bindings::utils::{domstring_to_jsval, WrapNewBindingObject};
 use dom::bindings::utils::{str, CacheableWrapper, DOM_OBJECT_SLOT};
-use dom::bindings::utils;
 use dom::bindings::clientrectlist::ClientRectListImpl;
 use dom::element::*;
 use dom::node::{AbstractNode, Node, Element, ElementNodeTypeId};
@@ -22,7 +21,7 @@ use js::{JS_ARGV, JSCLASS_HAS_RESERVED_SLOTS, JSPROP_ENUMERATE, JSPROP_SHARED, J
 use js::{JS_THIS_OBJECT, JS_SET_RVAL, JSPROP_NATIVE_ACCESSORS};
 
 extern fn finalize(_fop: *JSFreeOp, obj: *JSObject) {
-    debug!("element finalize!");
+    debug!("element finalize: %?!", obj as uint);
     unsafe {
         let val = JS_GetReservedSlot(obj, DOM_OBJECT_SLOT as u32);
         let node: AbstractNode = cast::reinterpret_cast(&RUST_JSVAL_TO_PRIVATE(val));
@@ -123,8 +122,7 @@ extern fn HTMLImageElement_getWidth(cx: *JSContext, _argc: c_uint, vp: *mut JSVa
         let width = match node.type_id() {
             ElementNodeTypeId(HTMLImageElementTypeId) => {
                 let content = task_from_context(cx);
-                let node = Node::as_abstract_node(~*node);
-                match (*content).query_layout(layout_task::ContentBox(node)) {
+                match (*content).query_layout(layout_task::ContentBox(*node)) {
                     Ok(rect) => rect.width,
                     Err(()) => 0
                 }
diff --git a/src/servo/dom/bindings/htmlcollection.rs b/src/servo/dom/bindings/htmlcollection.rs
new file mode 100644
index 00000000000..319f9095532
--- /dev/null
+++ b/src/servo/dom/bindings/htmlcollection.rs
@@ -0,0 +1,65 @@
+use content::content_task::task_from_context;
+use dom::element::Element;
+use dom::node::AbstractNode;
+use dom::bindings::codegen::HTMLCollectionBinding;
+use dom::bindings::utils::{DOMString, ErrorResult, OpaqueBindingReference};
+use dom::bindings::utils::{CacheableWrapper, BindingObject, WrapperCache};
+use js::jsapi::{JSObject, JSContext};
+
+pub struct HTMLCollection {
+    elements: ~[AbstractNode],
+    wrapper: WrapperCache
+}
+
+pub impl HTMLCollection {
+    static fn new(elements: ~[AbstractNode]) -> HTMLCollection {
+        HTMLCollection {
+            elements: elements,
+            wrapper: WrapperCache::new()
+        }
+    }
+    
+    fn Length(&self) -> u32 {
+        self.elements.len() as u32
+    }
+
+    fn Item(&self, index: u32) -> Option<AbstractNode> {
+        if index < self.Length() {
+            Some(self.elements[index])
+        } else {
+            None
+        }
+    }
+
+    fn NamedItem(&self, cx: *JSContext, name: DOMString, rv: &mut ErrorResult) -> *JSObject {
+        *rv = Ok(());
+        ptr::null()
+    }
+
+    fn IndexedGetter(&self, index: u32, found: &mut bool) -> Option<AbstractNode> {
+        *found = true;
+        self.Item(index)
+    }
+}
+
+impl BindingObject for HTMLCollection {
+    fn GetParentObject(&self, cx: *JSContext) -> OpaqueBindingReference {
+        let content = task_from_context(cx);
+        unsafe { OpaqueBindingReference(Right((*content).window.get() as @CacheableWrapper)) }
+    }
+}
+
+impl CacheableWrapper for HTMLCollection {
+    fn get_wrappercache(&mut self) -> &mut WrapperCache {
+        unsafe { cast::transmute(&self.wrapper) }
+    }
+
+    fn wrap_object_unique(~self, cx: *JSContext, scope: *JSObject) -> *JSObject {
+        let mut unused = false;
+        HTMLCollectionBinding::Wrap(cx, scope, self, &mut unused)
+    }
+
+    fn wrap_object_shared(@self, cx: *JSContext, scope: *JSObject) -> *JSObject {
+        fail!(~"nyi")
+    }
+}
diff --git a/src/servo/dom/bindings/utils.rs b/src/servo/dom/bindings/utils.rs
index 9d2b5a135b4..35c74548bf8 100644
--- a/src/servo/dom/bindings/utils.rs
+++ b/src/servo/dom/bindings/utils.rs
@@ -13,9 +13,10 @@ use js::jsapi::bindgen::{JS_ValueToString, JS_GetStringCharsZAndLength, JS_Repor
                          JS_GetFunctionPrototype, JS_InternString, JS_GetFunctionObject,
                          JS_GetInternedStringCharsAndLength, JS_DefineProperties,
                          JS_WrapValue, JS_GetObjectPrototype, JS_ForwardGetPropertyTo,
-                         JS_HasPropertyById, JS_GetPrototype, JS_GetGlobalForObject};
+                         JS_HasPropertyById, JS_GetPrototype, JS_GetGlobalForObject,
+                         JS_EncodeString, JS_free};
 use js::jsfriendapi::bindgen::JS_NewObjectWithUniqueType;
-use js::glue::bindgen::{DefineFunctionWithReserved, GetObjectJSClass};
+use js::glue::bindgen::{DefineFunctionWithReserved, GetObjectJSClass, RUST_OBJECT_TO_JSVAL};
 use js::glue::{PROPERTY_STUB, STRICT_PROPERTY_STUB, ENUMERATE_STUB, CONVERT_STUB,
                   RESOLVE_STUB};
 use js::glue::bindgen::*;
@@ -25,6 +26,9 @@ use content::content_task::{Content, task_from_context};
 
 use core::hashmap::linear;
 
+use dom::bindings::node;
+use dom::node::AbstractNode;
+
 const TOSTRING_CLASS_RESERVED_SLOT: u64 = 0;
 const TOSTRING_NAME_RESERVED_SLOT: u64 = 1;
 
@@ -131,15 +135,11 @@ pub fn jsval_to_str(cx: *JSContext, v: JSVal) -> Result<~str, ()> {
         }
     }
 
-    let len = 0;
-    let chars = JS_GetStringCharsZAndLength(cx, jsstr, ptr::to_unsafe_ptr(&len));
-    return if chars.is_null() {
-        Err(())
-    } else {
-        unsafe {
-            let buf = vec::raw::from_buf_raw(chars as *u8, len as uint);
-            Ok(str::from_bytes(buf))
-        }
+    unsafe {
+        let strbuf = JS_EncodeString(cx, jsstr);
+        let buf = str::raw::from_buf(strbuf as *u8);
+        JS_free(cx, strbuf as *libc::c_void);
+        Ok(buf)
     }
 }
 
@@ -330,7 +330,7 @@ pub struct ConstantSpec {
 pub struct DOMClass {
     // A list of interfaces that this object implements, in order of decreasing
     // derivedness.
-    interface_chain: [prototypes::id::Prototype * 2 /*prototypes::id::_ID_Count*/],
+    interface_chain: [prototypes::id::Prototype * 2 /*max prototype chain length*/],
 
     unused: bool, // DOMObjectIsISupports (always false)
     native_hooks: *NativePropertyHooks
@@ -353,6 +353,7 @@ pub mod prototypes {
         pub enum Prototype {
             ClientRect,
             ClientRectList,
+            HTMLCollection,
             _ID_Count
         }
     }
@@ -540,7 +541,7 @@ pub extern fn ThrowingConstructor(cx: *JSContext, argc: uint, vp: *JSVal) -> JSB
 }
 
 pub fn initialize_global(global: *JSObject) {
-    let protoArray = @mut [0 as *JSObject, ..2]; //XXXjdm number of constructors
+    let protoArray = @mut [0 as *JSObject, ..3]; //XXXjdm prototypes::_ID_COUNT
     unsafe {
         //XXXjdm we should be storing the box pointer instead of the inner
         let box = squirrel_away(protoArray);
@@ -777,4 +778,27 @@ pub fn InitIds(cx: *JSContext, specs: &[JSPropertySpec], ids: &mut [jsid]) -> bo
         }
     }
     rval
-}
\ No newline at end of file
+}
+
+pub trait DerivedWrapper {
+    fn wrap(&mut self, cx: *JSContext, scope: *JSObject, vp: *mut JSVal) -> i32;
+}
+
+impl DerivedWrapper for AbstractNode {
+    fn wrap(&mut self, cx: *JSContext, scope: *JSObject, vp: *mut JSVal) -> i32 {
+        let cache = self.get_wrappercache();
+        let wrapper = cache.get_wrapper();
+        if wrapper.is_not_null() {
+            unsafe { *vp = RUST_OBJECT_TO_JSVAL(wrapper) };
+            return 1;
+        }
+        unsafe { *vp = RUST_OBJECT_TO_JSVAL(node::create(cx, self).ptr) };
+        return 1;
+    }
+}
+
+pub enum Error {
+    FailureUnknown
+}
+
+pub type ErrorResult = Result<(), Error>;
\ No newline at end of file
diff --git a/src/servo/dom/document.rs b/src/servo/dom/document.rs
index 18b033a4934..d47b473663c 100644
--- a/src/servo/dom/document.rs
+++ b/src/servo/dom/document.rs
@@ -1,3 +1,5 @@
+use dom::bindings::htmlcollection::HTMLCollection;
+use dom::bindings::utils::{DOMString, WrapperCache, str};
 use dom::node::AbstractNode;
 use newcss::stylesheet::Stylesheet;
 
@@ -5,10 +7,32 @@ use std::arc::ARC;
 
 pub struct Document {
     root: AbstractNode,
+    wrapper: WrapperCache
 }
 
 pub fn Document(root: AbstractNode) -> Document {
     Document {
         root: root,
+        wrapper: WrapperCache::new()
     }
 }
+
+pub impl Document {
+    fn getElementsByTagName(&self, tag: DOMString) -> Option<~HTMLCollection> {
+        let mut elements = ~[];
+        let tag = match tag {
+          str(s) => s,
+          _ => ~""
+        };
+        let _ = for self.root.traverse_preorder |child| {
+            if child.is_element() {
+                do child.with_imm_element |elem| {
+                    if elem.tag_name == tag {
+                        elements.push(child);
+                    }
+                }
+            }
+        };
+        Some(~HTMLCollection::new(elements))
+    }
+}
\ No newline at end of file
diff --git a/src/servo/dom/node.rs b/src/servo/dom/node.rs
index 54a86bf871f..2f6bd608449 100644
--- a/src/servo/dom/node.rs
+++ b/src/servo/dom/node.rs
@@ -390,4 +390,7 @@ pub fn define_bindings(compartment: @mut Compartment, doc: @mut Document, win: @
     fail_unless!(codegen::ClientRectListBinding::DefineDOMInterface(compartment.cx.ptr,
                                                                     compartment.global_obj.ptr,
                                                                     &mut unused));
+    fail_unless!(codegen::HTMLCollectionBinding::DefineDOMInterface(compartment.cx.ptr,
+                                                                    compartment.global_obj.ptr,
+                                                                    &mut unused));
 }
diff --git a/src/servo/servo.rc b/src/servo/servo.rc
index f2dbdef6ec8..9d5b12820cb 100755
--- a/src/servo/servo.rc
+++ b/src/servo/servo.rc
@@ -49,9 +49,11 @@ pub mod dom {
         pub mod proxyhandler;
         pub mod clientrect;
         pub mod clientrectlist;
+        pub mod htmlcollection;
         pub mod codegen {
             pub mod ClientRectBinding;
             pub mod ClientRectListBinding;
+            pub mod HTMLCollectionBinding;
         }
     }
     pub mod document;
diff --git a/src/test/test_bindings.html b/src/test/test_bindings.html
index d40ed32fe9e..7b906908e1c 100644
--- a/src/test/test_bindings.html
+++ b/src/test/test_bindings.html
@@ -1 +1,11 @@
-<script src="test_bindings.js"></script>
+<html>
+  <head>
+    <script src="test_bindings.js"></script>
+  </head>
+  <body>
+    <div id="first"></div>
+    <div id="second"></div>
+    <span id="third"></div>
+    <div id="fourth"></div>
+  </body>
+</html>
diff --git a/src/test/test_bindings.js b/src/test/test_bindings.js
index 1823cc4ba9f..1f48599d08e 100644
--- a/src/test/test_bindings.js
+++ b/src/test/test_bindings.js
@@ -23,3 +23,12 @@ window.alert(rect.right);
 window.alert(rect.width);
 window.alert(rect.height);
 
+window.alert("HTMLCollection:");
+let tags = document.getElementsByTagName("head");
+//let tag = tags[0];
+window.alert(tags);
+window.alert(tags.length);
+window.alert(tags[0]);
+window.alert(tags[1]);
+window.alert(tags[2]);
+window.alert(tags[3]);