chromium/src/third_party/blink/renderer/core/html/html_template_element.cc

/*
 * Copyright (C) 2012 Google Inc. All rights reserved.
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 * modification, are permitted provided that the following conditions are
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 *
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 * in the documentation and/or other materials provided with the
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 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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#include "third_party/blink/renderer/core/html/html_template_element.h"

#include "third_party/blink/renderer/core/dom/document.h"
#include "third_party/blink/renderer/core/dom/document_fragment.h"
#include "third_party/blink/renderer/core/dom/template_content_document_fragment.h"
#include "third_party/blink/renderer/core/frame/web_feature.h"
#include "third_party/blink/renderer/platform/instrumentation/use_counter.h"

namespace blink {

HTMLTemplateElement::HTMLTemplateElement(Document& document)
    : HTMLElement(html_names::kTemplateTag, document) {
  UseCounter::Count(document, WebFeature::kHTMLTemplateElement);
}

HTMLTemplateElement::~HTMLTemplateElement() = default;

DocumentFragment* HTMLTemplateElement::ContentInternal() const {
  if (!content_ && GetExecutionContext())
    content_ = MakeGarbageCollected<TemplateContentDocumentFragment>(
        GetDocument().EnsureTemplateDocument(),
        const_cast<HTMLTemplateElement*>(this));

  return content_.Get();
}

DocumentFragment* HTMLTemplateElement::content() const {
  return IsDeclarativeShadowRoot() ? nullptr : ContentInternal();
}

DocumentFragment* HTMLTemplateElement::DeclarativeShadowContent() const {
  return IsDeclarativeShadowRoot() ? ContentInternal() : nullptr;
}

// https://html.spec.whatwg.org/C/#the-template-element:concept-node-clone-ext
void HTMLTemplateElement::CloneNonAttributePropertiesFrom(
    const Element& source,
    CloneChildrenFlag flag) {
  if (flag == CloneChildrenFlag::kSkip || !GetExecutionContext())
    return;
  DCHECK_NE(flag, CloneChildrenFlag::kCloneWithShadows);
  auto& html_template_element = To<HTMLTemplateElement>(source);
  if (html_template_element.content())
    content()->CloneChildNodesFrom(*html_template_element.content(), flag);
}

void HTMLTemplateElement::DidMoveToNewDocument(Document& old_document) {
  HTMLElement::DidMoveToNewDocument(old_document);
  if (!content_ || !GetExecutionContext())
    return;
  GetDocument().EnsureTemplateDocument().AdoptIfNeeded(*content_);
}

void HTMLTemplateElement::Trace(Visitor* visitor) const {
  visitor->Trace(content_);
  HTMLElement::Trace(visitor);
}

}  // namespace blink