dom/html/HTMLAllCollection.cpp
author Aryeh Gregor <ayg@aryeh.name>
Sun, 13 Aug 2017 16:19:32 +0300
changeset 646567 16a658986ad3d01cb27dae3b63446bd1f8291595
parent 646566 f3a6d9769c233a0e126e7b31c0733089049acbe3
permissions -rw-r--r--
Bug 1389922 - Return new object each time from document.all; r?smaug In accordance with the spec, Chrome, WebKit, and Edge. We now pass all relevant wpt tests, after https://github.com/w3c/web-platform-tests/pull/6820 is merged upstream. MozReview-Commit-ID: LoPtBsAXkWn

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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/. */

#include "mozilla/dom/HTMLAllCollection.h"

#include "mozilla/dom/HTMLAllCollectionBinding.h"
#include "mozilla/dom/Nullable.h"
#include "mozilla/dom/Element.h"
#include "nsHTMLDocument.h"

namespace mozilla {
namespace dom {

HTMLAllCollection::HTMLAllCollection(nsHTMLDocument* aDocument)
  : mDocument(aDocument)
{
  MOZ_ASSERT(mDocument);
}

HTMLAllCollection::~HTMLAllCollection()
{
}

NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(HTMLAllCollection,
                                      mDocument,
                                      mCollection,
                                      mNamedMap)

NS_IMPL_CYCLE_COLLECTING_ADDREF(HTMLAllCollection)
NS_IMPL_CYCLE_COLLECTING_RELEASE(HTMLAllCollection)

NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(HTMLAllCollection)
  NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
  NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END

nsINode*
HTMLAllCollection::GetParentObject() const
{
  return mDocument;
}

uint32_t
HTMLAllCollection::Length()
{
  return Collection()->Length(true);
}

Element*
HTMLAllCollection::Item(uint32_t aIndex)
{
  nsCOMPtr<nsIContent> content = Collection()->Item(aIndex);
  return content ? content->AsElement() : nullptr;
}

/**
 * Helper for the next method.  If the string is equal to a simple serialization
 * of an integer in the range [0, UINT32_MAX) (excluding the endpoint!), return
 * it.  Otherwise return UINT32_MAX, which indicates it is not an array index
 * property name.
 */
static uint32_t GetAsArrayIndexPropertyName(const nsAString& aStr) {
  uint32_t val = 0;
  for (uint32_t i = 0; i < aStr.Length(); i++) {
    if (aStr[i] < '0' || aStr[i] > '9') {
      return UINT32_MAX;
    }
    if (aStr[i] == '0' && (i != 0 || aStr.Length() != 1)) {
      // Leading 0, invalid
      return UINT32_MAX;
    }
    uint32_t origVal = val;
    val = val * 10 + aStr[i] - '0';
    if (val < origVal) {
      // Overflow, invalid array index
      return UINT32_MAX;
    }
  }
  // UINT32_MAX is an invalid array index too, but we don't have to check for
  // it specially, because it's also our error return value.
  return val;
}

void
HTMLAllCollection::Item(const Optional<nsAString>& aName,
                        Nullable<OwningHTMLCollectionOrElement>& aResult)
{
  if (!aName.WasPassed()) {
    aResult.SetNull();
    return;
  }
  uint32_t val = GetAsArrayIndexPropertyName(aName.Value());
  if (val != UINT32_MAX) {
    Element* elem = Item(val);
    if (elem) {
      aResult.SetValue().SetAsElement() = elem;
    } else {
      aResult.SetNull();
    }
    return;
  }
  NamedItem(aName.Value(), aResult);
}

nsContentList*
HTMLAllCollection::Collection()
{
  if (!mCollection) {
    nsIDocument* document = mDocument;
    mCollection = document->GetElementsByTagName(NS_LITERAL_STRING("*"));
    MOZ_ASSERT(mCollection);
  }
  return mCollection;
}

static bool
IsAllNamedElement(nsIContent* aContent)
{
  return aContent->IsAnyOfHTMLElements(nsGkAtoms::a,
                                       nsGkAtoms::button,
                                       nsGkAtoms::embed,
                                       nsGkAtoms::form,
                                       nsGkAtoms::iframe,
                                       nsGkAtoms::img,
                                       nsGkAtoms::input,
                                       nsGkAtoms::map,
                                       nsGkAtoms::meta,
                                       nsGkAtoms::object,
                                       nsGkAtoms::select,
                                       nsGkAtoms::textarea,
                                       nsGkAtoms::frame,
                                       nsGkAtoms::frameset);
}

static bool
DocAllResultMatch(Element* aElement, int32_t aNamespaceID, nsIAtom* aAtom,
                  void* aData)
{
  if (aElement->GetID() == aAtom) {
    return true;
  }

  nsGenericHTMLElement* elm = nsGenericHTMLElement::FromContent(aElement);
  if (!elm) {
    return false;
  }

  if (!IsAllNamedElement(elm)) {
    return false;
  }

  const nsAttrValue* val = elm->GetParsedAttr(nsGkAtoms::name);
  return val && val->Type() == nsAttrValue::eAtom &&
         val->GetAtomValue() == aAtom;
}

nsContentList*
HTMLAllCollection::GetDocumentAllList(const nsAString& aID)
{
  return mNamedMap.LookupForAdd(aID).OrInsert(
    [this, &aID] () {
      nsCOMPtr<nsIAtom> id = NS_Atomize(aID);
      return new nsContentList(mDocument, DocAllResultMatch, nullptr,
                               nullptr, true, id);
    });
}

void
HTMLAllCollection::NamedGetter(const nsAString& aID,
                               bool& aFound,
                               Nullable<OwningHTMLCollectionOrElement>& aResult)
{
  if (aID.IsEmpty()) {
    aFound = false;
    aResult.SetNull();
    return;
  }

  nsContentList* docAllList = GetDocumentAllList(aID);
  if (!docAllList) {
    aFound = false;
    aResult.SetNull();
    return;
  }

  // Check if there are more than 1 entries. Do this by getting the second one
  // rather than the length since getting the length always requires walking
  // the entire document.
  if (docAllList->Item(1, true)) {
    aFound = true;
    // We need to return a different value for each call per spec
    nsCOMPtr<nsIAtom> id = NS_Atomize(aID);
    aResult.SetValue().SetAsHTMLCollection() =
      new nsContentList(mDocument, DocAllResultMatch, nullptr, nullptr, true,
                        id);
    return;
  }

  // There's only 0 or 1 items. Return the first one or null.
  if (nsIContent* node = docAllList->Item(0, true)) {
    aFound = true;
    aResult.SetValue().SetAsElement() = node->AsElement();
    return;
  }

  aFound = false;
  aResult.SetNull();
}

void
HTMLAllCollection::GetSupportedNames(nsTArray<nsString>& aNames)
{
  // XXXbz this is very similar to nsContentList::GetSupportedNames,
  // but has to check IsAllNamedElement for the name case.
  AutoTArray<nsIAtom*, 8> atoms;
  for (uint32_t i = 0; i < Length(); ++i) {
    nsIContent *content = Item(i);
    if (content->HasID()) {
      nsIAtom* id = content->GetID();
      MOZ_ASSERT(id != nsGkAtoms::_empty,
                 "Empty ids don't get atomized");
      if (!atoms.Contains(id)) {
        atoms.AppendElement(id);
      }
    }

    nsGenericHTMLElement* el = nsGenericHTMLElement::FromContent(content);
    if (el) {
      // Note: nsINode::HasName means the name is exposed on the document,
      // which is false for options, so we don't check it here.
      const nsAttrValue* val = el->GetParsedAttr(nsGkAtoms::name);
      if (val && val->Type() == nsAttrValue::eAtom &&
          IsAllNamedElement(content)) {
        nsIAtom* name = val->GetAtomValue();
        MOZ_ASSERT(name != nsGkAtoms::_empty,
                   "Empty names don't get atomized");
        if (!atoms.Contains(name)) {
          atoms.AppendElement(name);
        }
      }
    }
  }

  uint32_t atomsLen = atoms.Length();
  nsString* names = aNames.AppendElements(atomsLen);
  for (uint32_t i = 0; i < atomsLen; ++i) {
    atoms[i]->ToString(names[i]);
  }
}


JSObject*
HTMLAllCollection::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
{
  return HTMLAllCollectionBinding::Wrap(aCx, this, aGivenProto);
}

} // namespace dom
} // namespace mozilla