LibWeb: Implement DOMStringList

Author: https://github.com/jamierocks
Commit: https://github.com/LadybirdBrowser/ladybird/commit/75216182c9a
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/731
Reviewed-by: https://github.com/AtkinsSJ

Meta/gn/secondary/Userland/Libraries/LibWeb/HTML/BUILD.gn

@@ -26,6 +26,7 @@ source_set("HTML") {
     "CloseWatcher.cpp",
     "CloseWatcherManager.cpp",
     "DOMParser.cpp",
+    "DOMStringList.cpp",
     "DOMStringMap.cpp",
     "DataTransfer.cpp",
     "Dates.cpp",

Meta/gn/secondary/Userland/Libraries/LibWeb/idl_files.gni

@@ -119,6 +119,7 @@ standard_idl_files = [
   "//Userland/Libraries/LibWeb/HTML/CustomElements/CustomElementRegistry.idl",
   "//Userland/Libraries/LibWeb/HTML/DataTransfer.idl",
   "//Userland/Libraries/LibWeb/HTML/DOMParser.idl",
+  "//Userland/Libraries/LibWeb/HTML/DOMStringList.idl",
   "//Userland/Libraries/LibWeb/HTML/DOMStringMap.idl",
   "//Userland/Libraries/LibWeb/HTML/ElementInternals.idl",
   "//Userland/Libraries/LibWeb/HTML/ErrorEvent.idl",

Tests/LibWeb/Text/expected/all-window-properties.txt

@@ -70,6 +70,7 @@ DOMQuad
 DOMRect
 DOMRectList
 DOMRectReadOnly
+DOMStringList
 DOMStringMap
 DOMTokenList
 DataTransfer

Userland/Libraries/LibWeb/CMakeLists.txt

@@ -280,6 +280,7 @@ set(SOURCES
     HTML/DedicatedWorkerGlobalScope.cpp
     HTML/DocumentState.cpp
     HTML/DOMParser.cpp
+    HTML/DOMStringList.cpp
     HTML/DOMStringMap.cpp
     HTML/DragEvent.cpp
     HTML/ElementInternals.cpp

Userland/Libraries/LibWeb/Forward.h

@@ -360,6 +360,7 @@ class CustomElementRegistry;
 class DecodedImageData;
 class DocumentState;
 class DOMParser;
+class DOMStringList;
 class DOMStringMap;
 class DragEvent;
 class ElementInternals;

Userland/Libraries/LibWeb/HTML/DOMStringList.cpp

@@ -0,0 +1,74 @@
+/*
+ * Copyright (c) 2024, Jamie Mansfield <jmansfield@cadixdev.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibWeb/Bindings/DOMStringListPrototype.h>
+#include <LibWeb/Bindings/Intrinsics.h>
+#include <LibWeb/HTML/DOMStringList.h>
+#include <LibWeb/WebIDL/ExceptionOr.h>
+
+namespace Web::HTML {
+
+JS_DEFINE_ALLOCATOR(DOMStringList);
+
+JS::NonnullGCPtr<DOMStringList> DOMStringList::create(JS::Realm& realm, Vector<String> list)
+{
+    return realm.heap().allocate<DOMStringList>(realm, realm, list);
+}
+
+DOMStringList::DOMStringList(JS::Realm& realm, Vector<String> list)
+    : Bindings::PlatformObject(realm)
+    , m_list(move(list))
+{
+    m_legacy_platform_object_flags = LegacyPlatformObjectFlags { .supports_indexed_properties = true };
+}
+
+void DOMStringList::initialize(JS::Realm& realm)
+{
+    Base::initialize(realm);
+    WEB_SET_PROTOTYPE_FOR_INTERFACE(DOMStringList);
+}
+
+// https://html.spec.whatwg.org/multipage/common-dom-interfaces.html#dom-domstringlist-length
+u32 DOMStringList::length() const
+{
+    // The length getter steps are to return this's associated list's size.
+    return m_list.size();
+}
+
+// https://html.spec.whatwg.org/multipage/common-dom-interfaces.html#dom-domstringlist-item
+Optional<String> DOMStringList::item(u32 index) const
+{
+    // The item(index) method steps are to return the indexth item in this's associated list, or null if index plus one
+    // is greater than this's associated list's size.
+    if (index + 1 > m_list.size())
+        return {};
+
+    return m_list.at(index);
+}
+
+// https://html.spec.whatwg.org/multipage/common-dom-interfaces.html#dom-domstringlist-contains
+bool DOMStringList::contains(StringView string)
+{
+    // The contains(string) method steps are to return true if this's associated list contains string, and false otherwise.
+    return m_list.contains_slow(string);
+}
+
+bool DOMStringList::is_supported_property_index(u32 index) const
+{
+    // The DOMStringList interface supports indexed properties. The supported property indices are the indices of this's
+    // associated list.
+    return index < m_list.size();
+}
+
+WebIDL::ExceptionOr<JS::Value> DOMStringList::item_value(size_t index) const
+{
+    if (index + 1 > m_list.size())
+        return JS::js_undefined();
+
+    return JS::PrimitiveString::create(vm(), m_list.at(index));
+}
+
+}

Userland/Libraries/LibWeb/HTML/DOMStringList.h

@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2024, Jamie Mansfield <jmansfield@cadixdev.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/Vector.h>
+#include <LibWeb/Bindings/PlatformObject.h>
+
+namespace Web::HTML {
+
+class DOMStringList final : public Bindings::PlatformObject {
+    WEB_PLATFORM_OBJECT(DOMStringList, Bindings::PlatformObject);
+    JS_DECLARE_ALLOCATOR(DOMStringList);
+
+public:
+    static JS::NonnullGCPtr<DOMStringList> create(JS::Realm&, Vector<String>);
+
+    u32 length() const;
+    Optional<String> item(u32 index) const;
+    bool contains(StringView string);
+
+    virtual bool is_supported_property_index(u32) const override;
+    virtual WebIDL::ExceptionOr<JS::Value> item_value(size_t index) const override;
+
+private:
+    explicit DOMStringList(JS::Realm&, Vector<String>);
+
+    virtual void initialize(JS::Realm&) override;
+
+    Vector<String> m_list;
+};
+
+}

Userland/Libraries/LibWeb/HTML/DOMStringList.idl

@@ -0,0 +1,7 @@
+// https://html.spec.whatwg.org/multipage/common-dom-interfaces.html#domstringlist
+[Exposed=(Window,Worker)]
+interface DOMStringList {
+    readonly attribute unsigned long length;
+    getter DOMString? item(unsigned long index);
+    boolean contains(DOMString string);
+};

Userland/Libraries/LibWeb/idl_files.cmake

@@ -104,6 +104,7 @@ libweb_js_bindings(HTML/CustomElements/CustomElementRegistry)
 libweb_js_bindings(HTML/DataTransfer)
 libweb_js_bindings(HTML/DedicatedWorkerGlobalScope GLOBAL)
 libweb_js_bindings(HTML/DOMParser)
+libweb_js_bindings(HTML/DOMStringList)
 libweb_js_bindings(HTML/DOMStringMap)
 libweb_js_bindings(HTML/DragEvent)
 libweb_js_bindings(HTML/ElementInternals)