chromium/src/third_party/blink/renderer/bindings/core/v8/script_custom_element_definition.cc

// Copyright 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "third_party/blink/renderer/bindings/core/v8/script_custom_element_definition.h"

#include "third_party/blink/renderer/bindings/core/v8/script_custom_element_definition_data.h"
#include "third_party/blink/renderer/bindings/core/v8/v8_binding_for_core.h"
#include "third_party/blink/renderer/bindings/core/v8/v8_custom_element_adopted_callback.h"
#include "third_party/blink/renderer/bindings/core/v8/v8_custom_element_attribute_changed_callback.h"
#include "third_party/blink/renderer/bindings/core/v8/v8_custom_element_constructor.h"
#include "third_party/blink/renderer/bindings/core/v8/v8_custom_element_form_associated_callback.h"
#include "third_party/blink/renderer/bindings/core/v8/v8_custom_element_form_disabled_callback.h"
#include "third_party/blink/renderer/bindings/core/v8/v8_custom_element_form_state_restore_callback.h"
#include "third_party/blink/renderer/bindings/core/v8/v8_custom_element_registry.h"
#include "third_party/blink/renderer/bindings/core/v8/v8_element.h"
#include "third_party/blink/renderer/bindings/core/v8/v8_form_state_restore_mode.h"
#include "third_party/blink/renderer/bindings/core/v8/v8_function.h"
#include "third_party/blink/renderer/bindings/core/v8/v8_script_runner.h"
#include "third_party/blink/renderer/bindings/core/v8/v8_throw_dom_exception.h"
#include "third_party/blink/renderer/bindings/core/v8/v8_void_function.h"
#include "third_party/blink/renderer/core/dom/document.h"
#include "third_party/blink/renderer/core/events/error_event.h"
#include "third_party/blink/renderer/core/execution_context/execution_context.h"
#include "third_party/blink/renderer/core/html/custom/custom_element.h"
#include "third_party/blink/renderer/core/html/html_element.h"
#include "third_party/blink/renderer/platform/bindings/script_state.h"
#include "third_party/blink/renderer/platform/bindings/v8_binding_macros.h"
#include "third_party/blink/renderer/platform/bindings/v8_per_context_data.h"
#include "third_party/blink/renderer/platform/bindings/v8_private_property.h"
#include "third_party/blink/renderer/platform/wtf/allocator/allocator.h"
#include "v8/include/v8.h"

namespace blink {

class CSSStyleSheet;

ScriptCustomElementDefinition* ScriptCustomElementDefinition::ForConstructor(
    ScriptState* script_state,
    CustomElementRegistry* registry,
    v8::Local<v8::Value> constructor) {
  V8PerContextData* per_context_data = script_state->PerContextData();
  // TODO(yukishiino): Remove this check when crbug.com/583429 is fixed.
  if (UNLIKELY(!per_context_data))
    return nullptr;
  auto private_id = per_context_data->GetPrivateCustomElementDefinitionId();
  v8::Local<v8::Value> id_value;
  if (!constructor.As<v8::Object>()
           ->GetPrivate(script_state->GetContext(), private_id)
           .ToLocal(&id_value))
    return nullptr;
  if (!id_value->IsUint32())
    return nullptr;
  uint32_t id = id_value.As<v8::Uint32>()->Value();

  // This downcast is safe because only ScriptCustomElementDefinitions
  // have an ID associated with them. This relies on three things:
  //
  // 1. Only ScriptCustomElementDefinition::Create sets the private
  //    property on a constructor.
  //
  // 2. CustomElementRegistry adds ScriptCustomElementDefinitions
  //    assigned an ID to the list of definitions without fail.
  //
  // 3. The relationship between the CustomElementRegistry and its
  //    private property is never mixed up; this is guaranteed by the
  //    bindings system because the registry is associated with its
  //    context.
  //
  // At a meta-level, this downcast is safe because there is
  // currently only one implementation of CustomElementDefinition in
  // product code and that is ScriptCustomElementDefinition. But
  // that may change in the future.
  CustomElementDefinition* definition = registry->DefinitionForId(id);
  CHECK(definition);
  return static_cast<ScriptCustomElementDefinition*>(definition);
}

ScriptCustomElementDefinition::ScriptCustomElementDefinition(
    const ScriptCustomElementDefinitionData& data,
    const CustomElementDescriptor& descriptor,
    CustomElementDefinition::Id id)
    : CustomElementDefinition(descriptor,
                              std::move(data.observed_attributes_),
                              data.disabled_features_,
                              data.is_form_associated_
                                  ? FormAssociationFlag::kYes
                                  : FormAssociationFlag::kNo),
      script_state_(data.script_state_),
      constructor_(data.constructor_),
      connected_callback_(data.connected_callback_),
      disconnected_callback_(data.disconnected_callback_),
      adopted_callback_(data.adopted_callback_),
      attribute_changed_callback_(data.attribute_changed_callback_),
      form_associated_callback_(data.form_associated_callback_),
      form_reset_callback_(data.form_reset_callback_),
      form_disabled_callback_(data.form_disabled_callback_),
      form_state_restore_callback_(data.form_state_restore_callback_) {
  // Tag the JavaScript constructor object with its ID.
  ScriptState* script_state = data.script_state_;
  v8::Local<v8::Value> id_value =
      v8::Integer::NewFromUnsigned(script_state->GetIsolate(), id);
  auto private_id =
      script_state->PerContextData()->GetPrivateCustomElementDefinitionId();
  CHECK(data.constructor_->CallbackObject()
            ->SetPrivate(script_state->GetContext(), private_id, id_value)
            .ToChecked());
}

void ScriptCustomElementDefinition::Trace(Visitor* visitor) const {
  visitor->Trace(script_state_);
  visitor->Trace(constructor_);
  visitor->Trace(connected_callback_);
  visitor->Trace(disconnected_callback_);
  visitor->Trace(adopted_callback_);
  visitor->Trace(attribute_changed_callback_);
  visitor->Trace(form_associated_callback_);
  visitor->Trace(form_reset_callback_);
  visitor->Trace(form_disabled_callback_);
  visitor->Trace(form_state_restore_callback_);
  CustomElementDefinition::Trace(visitor);
}

HTMLElement* ScriptCustomElementDefinition::HandleCreateElementSyncException(
    Document& document,
    const QualifiedName& tag_name,
    v8::Isolate* isolate,
    ExceptionState& exception_state) {
  DCHECK(exception_state.HadException());
  // 6.1."If any of these subsubsteps threw an exception".1
  // Report the exception.
  V8ScriptRunner::ReportException(isolate, exception_state.GetException());
  exception_state.ClearException();
  // ... .2 Return HTMLUnknownElement.
  return CustomElement::CreateFailedElement(document, tag_name);
}

HTMLElement* ScriptCustomElementDefinition::CreateAutonomousCustomElementSync(
    Document& document,
    const QualifiedName& tag_name) {
  DCHECK(CustomElement::ShouldCreateCustomElement(tag_name)) << tag_name;
  if (!script_state_->ContextIsValid())
    return CustomElement::CreateFailedElement(document, tag_name);
  ScriptState::Scope scope(script_state_);
  v8::Isolate* isolate = script_state_->GetIsolate();

  ExceptionState exception_state(isolate, ExceptionState::kConstructionContext,
                                 "CustomElement");

  // Create an element with the synchronous custom elements flag set.
  // https://dom.spec.whatwg.org/#concept-create-element

  // TODO(dominicc): Implement step 5 which constructs customized
  // built-in elements.

  Element* element = nullptr;
  {
    v8::TryCatch try_catch(script_state_->GetIsolate());

    if (document.IsHTMLImport()) {
      // V8HTMLElement::constructorCustom() can only refer to
      // window.document() which is not the import document. Create
      // elements in import documents ahead of time so they end up in
      // the right document. This subtly violates recursive
      // construction semantics, but only in import documents.
      element = CreateElementForConstructor(document);
      DCHECK(!try_catch.HasCaught());

      ConstructionStackScope construction_stack_scope(*this, *element);
      element = CallConstructor();
    } else {
      element = CallConstructor();
    }

    if (try_catch.HasCaught()) {
      exception_state.RethrowV8Exception(try_catch.Exception());
      return HandleCreateElementSyncException(document, tag_name, isolate,
                                              exception_state);
    }
  }

  // 6.1.3. through 6.1.9.
  CheckConstructorResult(element, document, tag_name, exception_state);
  if (exception_state.HadException()) {
    return HandleCreateElementSyncException(document, tag_name, isolate,
                                            exception_state);
  }
  // 6.1.10. Set result’s namespace prefix to prefix.
  if (element->prefix() != tag_name.Prefix())
    element->SetTagNameForCreateElementNS(tag_name);
  DCHECK_EQ(element->GetCustomElementState(), CustomElementState::kCustom);
  AddDefaultStylesTo(*element);
  return To<HTMLElement>(element);
}

// https://html.spec.whatwg.org/C/#upgrades
bool ScriptCustomElementDefinition::RunConstructor(Element& element) {
  if (!script_state_->ContextIsValid())
    return false;
  ScriptState::Scope scope(script_state_);
  v8::Isolate* isolate = script_state_->GetIsolate();

  // Step 5 says to rethrow the exception; but there is no one to
  // catch it. The side effect is to report the error.
  v8::TryCatch try_catch(isolate);
  try_catch.SetVerbose(true);

  if (DisableShadow() && element.GetShadowRoot()) {
    v8::Local<v8::Value> exception = V8ThrowDOMException::CreateOrEmpty(
        script_state_->GetIsolate(), DOMExceptionCode::kNotSupportedError,
        "The element already has a ShadowRoot though it is disabled by "
        "disabledFeatures static field.");
    if (!exception.IsEmpty())
      V8ScriptRunner::ReportException(isolate, exception);
    return false;
  }

  // 8.1.new: set custom element state to kPreCustomized.
  element.SetCustomElementState(CustomElementState::kPreCustomized);

  Element* result = CallConstructor();

  // To report exception thrown from callConstructor()
  if (try_catch.HasCaught())
    return false;

  // Report a TypeError Exception if the constructor returns a different object.
  if (result != &element) {
    const String& message =
        "custom element constructors must call super() first and must "
        "not return a different object";
    v8::Local<v8::Value> exception =
        V8ThrowException::CreateTypeError(script_state_->GetIsolate(), message);
    if (!exception.IsEmpty())
      V8ScriptRunner::ReportException(isolate, exception);
    return false;
  }

  return true;
}

Element* ScriptCustomElementDefinition::CallConstructor() {
  ScriptValue result;
  if (!constructor_->Construct().To(&result)) {
    return nullptr;
  }

  return V8Element::ToImplWithTypeCheck(constructor_->GetIsolate(),
                                        result.V8Value());
}

v8::Local<v8::Object> ScriptCustomElementDefinition::Constructor() const {
  return constructor_->CallbackObject();
}

// CustomElementDefinition
ScriptValue ScriptCustomElementDefinition::GetConstructorForScript() {
  return ScriptValue(script_state_->GetIsolate(), Constructor());
}

bool ScriptCustomElementDefinition::HasConnectedCallback() const {
  return connected_callback_;
}

bool ScriptCustomElementDefinition::HasDisconnectedCallback() const {
  return disconnected_callback_;
}

bool ScriptCustomElementDefinition::HasAdoptedCallback() const {
  return adopted_callback_;
}

bool ScriptCustomElementDefinition::HasFormAssociatedCallback() const {
  return form_associated_callback_;
}

bool ScriptCustomElementDefinition::HasFormResetCallback() const {
  return form_reset_callback_;
}

bool ScriptCustomElementDefinition::HasFormDisabledCallback() const {
  return form_disabled_callback_;
}

bool ScriptCustomElementDefinition::HasFormStateRestoreCallback() const {
  return form_state_restore_callback_;
}

void ScriptCustomElementDefinition::RunConnectedCallback(Element& element) {
  if (!connected_callback_)
    return;

  connected_callback_->InvokeAndReportException(&element);
}

void ScriptCustomElementDefinition::RunDisconnectedCallback(Element& element) {
  if (!disconnected_callback_)
    return;

  disconnected_callback_->InvokeAndReportException(&element);
}

void ScriptCustomElementDefinition::RunAdoptedCallback(Element& element,
                                                       Document& old_owner,
                                                       Document& new_owner) {
  if (!adopted_callback_)
    return;

  adopted_callback_->InvokeAndReportException(&element, &old_owner, &new_owner);
}

void ScriptCustomElementDefinition::RunAttributeChangedCallback(
    Element& element,
    const QualifiedName& name,
    const AtomicString& old_value,
    const AtomicString& new_value) {
  if (!attribute_changed_callback_)
    return;

  attribute_changed_callback_->InvokeAndReportException(
      &element, name.LocalName(), old_value, new_value, name.NamespaceURI());
}

void ScriptCustomElementDefinition::RunFormAssociatedCallback(
    Element& element,
    HTMLFormElement* nullable_form) {
  if (!form_associated_callback_)
    return;
  form_associated_callback_->InvokeAndReportException(&element, nullable_form);
}

void ScriptCustomElementDefinition::RunFormResetCallback(Element& element) {
  if (!form_reset_callback_)
    return;
  form_reset_callback_->InvokeAndReportException(&element);
}

void ScriptCustomElementDefinition::RunFormDisabledCallback(Element& element,
                                                            bool is_disabled) {
  if (!form_disabled_callback_)
    return;
  form_disabled_callback_->InvokeAndReportException(&element, is_disabled);
}

void ScriptCustomElementDefinition::RunFormStateRestoreCallback(
    Element& element,
    const FileOrUSVStringOrFormData& value,
    const String& mode) {
  if (!form_state_restore_callback_)
    return;
#if defined(USE_BLINK_V8_BINDING_NEW_IDL_CALLBACK_FUNCTION)
  form_state_restore_callback_->InvokeAndReportException(
      &element, value, V8FormStateRestoreMode::Create(mode).value());
#else
  form_state_restore_callback_->InvokeAndReportException(&element, value, mode);
#endif
}

}  // namespace blink