ladybird/Userland/Libraries/LibWeb/DOM/HTMLCollection.cpp
Andreas Kling e4df1b223f LibWeb: Implement a slow but functional HTMLCollection :^)
HTMLCollection is an awkward legacy interface from the DOM spec.

It provides a live view of a DOM subtree, with some kind of filtering
that determines which elements are part of the collection.

We now return HTMLCollection objects from these APIs:

- getElementsByClassName()
- getElementsByName()
- getElementsByTagName()

This initial implementation does not do any kind of caching, since that
is quite a tricky problem, and there will be plenty of time for tricky
problems later on when the engine is more mature.
2021-04-22 21:21:46 +02:00

61 lines
1.6 KiB
C++

/*
* Copyright (c) 2021, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibWeb/DOM/Element.h>
#include <LibWeb/DOM/HTMLCollection.h>
#include <LibWeb/DOM/ParentNode.h>
namespace Web::DOM {
HTMLCollection::HTMLCollection(ParentNode& root, Function<bool(Element const&)> filter)
: m_root(root)
, m_filter(move(filter))
{
}
HTMLCollection::~HTMLCollection()
{
}
Vector<NonnullRefPtr<Element>> HTMLCollection::collect_matching_elements()
{
Vector<NonnullRefPtr<Element>> elements;
m_root->for_each_in_inclusive_subtree_of_type<Element>([&](auto& element) {
if (m_filter(element))
elements.append(element);
return IterationDecision::Continue;
});
return elements;
}
size_t HTMLCollection::length()
{
return collect_matching_elements().size();
}
Element* HTMLCollection::item(size_t index)
{
auto elements = collect_matching_elements();
if (index >= elements.size())
return nullptr;
return elements[index];
}
Element* HTMLCollection::named_item(FlyString const& name)
{
if (name.is_null())
return nullptr;
auto elements = collect_matching_elements();
// First look for an "id" attribute match
if (auto it = elements.find_if([&](auto& entry) { return entry->attribute(HTML::AttributeNames::id) == name; }); it != elements.end())
return *it;
// Then look for a "name" attribute match
if (auto it = elements.find_if([&](auto& entry) { return entry->name() == name; }); it != elements.end())
return *it;
return nullptr;
}
}