LibWeb: Add FormDataIterator implementation

This adds the FormDataIterator implementation so we can iterate over
FormData.{keys(),values(),entries()}.

Userland/Libraries/LibWeb/CMakeLists.txt

@@ -473,6 +473,7 @@ set(SOURCES
     WebSockets/WebSocket.cpp
     XHR/EventNames.cpp
     XHR/FormData.cpp
+    XHR/FormDataIterator.cpp
     XHR/ProgressEvent.cpp
     XHR/XMLHttpRequest.cpp
     XHR/XMLHttpRequestEventTarget.cpp

Userland/Libraries/LibWeb/Forward.h

@@ -489,6 +489,7 @@ class WebGLRenderingContextBase;
 
 namespace Web::XHR {
 class FormData;
+class FormDataIterator;
 class ProgressEvent;
 class XMLHttpRequest;
 class XMLHttpRequestEventTarget;

Userland/Libraries/LibWeb/XHR/FormData.cpp

@@ -171,4 +171,14 @@ WebIDL::ExceptionOr<void> FormData::set_impl(String const& name, Variant<JS::Non
     return {};
 }
 
+JS::ThrowCompletionOr<void> FormData::for_each(ForEachCallback callback)
+{
+    for (auto i = 0u; i < m_entry_list.size(); ++i) {
+        auto& entry = m_entry_list[i];
+        TRY(callback(entry.name, entry.value));
+    }
+
+    return {};
+}
+
 }

Userland/Libraries/LibWeb/XHR/FormData.h

@@ -41,7 +41,12 @@ public:
     WebIDL::ExceptionOr<void> set(String const& name, String const& value);
     WebIDL::ExceptionOr<void> set(String const& name, JS::NonnullGCPtr<FileAPI::Blob> const& blob_value, Optional<String> const& filename = {});
 
+    using ForEachCallback = Function<JS::ThrowCompletionOr<void>(String const&, FormDataEntryValue const&)>;
+    JS::ThrowCompletionOr<void> for_each(ForEachCallback);
+
 private:
+    friend class FormDataIterator;
+
     explicit FormData(JS::Realm&, Vector<FormDataEntry> entry_list = {});
 
     virtual JS::ThrowCompletionOr<void> initialize(JS::Realm&) override;

Userland/Libraries/LibWeb/XHR/FormData.idl

@@ -19,5 +19,5 @@ interface FormData {
     boolean has(USVString name);
     undefined set(USVString name, USVString value);
     undefined set(USVString name, Blob blobValue, optional USVString filename);
-    // FIXME: iterable<USVString, FormDataEntryValue>;
+    iterable<USVString, FormDataEntryValue>;
 };

Userland/Libraries/LibWeb/XHR/FormDataIterator.cpp

@@ -0,0 +1,79 @@
+/*
+ * Copyright (c) 2023, Kenneth Myhra <kennethmyhra@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibJS/Runtime/Array.h>
+#include <LibJS/Runtime/IteratorOperations.h>
+#include <LibWeb/Bindings/FormDataIteratorPrototype.h>
+#include <LibWeb/Bindings/Intrinsics.h>
+#include <LibWeb/XHR/FormDataIterator.h>
+
+namespace Web::Bindings {
+
+template<>
+void Intrinsics::create_web_prototype_and_constructor<FormDataIteratorPrototype>(JS::Realm& realm)
+{
+    auto prototype = heap().allocate<FormDataIteratorPrototype>(realm, realm).release_allocated_value_but_fixme_should_propagate_errors();
+    m_prototypes.set("FormDataIterator"sv, prototype);
+}
+
+}
+
+namespace Web::XHR {
+
+WebIDL::ExceptionOr<JS::NonnullGCPtr<FormDataIterator>> FormDataIterator::create(FormData const& form_data, JS::Object::PropertyKind iterator_kind)
+{
+    return MUST_OR_THROW_OOM(form_data.heap().allocate<FormDataIterator>(form_data.realm(), form_data, iterator_kind));
+}
+
+FormDataIterator::FormDataIterator(Web::XHR::FormData const& form_data, JS::Object::PropertyKind iterator_kind)
+    : PlatformObject(form_data.realm())
+    , m_form_data(form_data)
+    , m_iterator_kind(iterator_kind)
+{
+}
+
+FormDataIterator::~FormDataIterator() = default;
+
+JS::ThrowCompletionOr<void> FormDataIterator::initialize(JS::Realm& realm)
+{
+    MUST_OR_THROW_OOM(Base::initialize(realm));
+    set_prototype(&Bindings::ensure_web_prototype<Bindings::FormDataIteratorPrototype>(realm, "FormDataIterator"));
+
+    return {};
+}
+
+void FormDataIterator::visit_edges(Cell::Visitor& visitor)
+{
+    Base::visit_edges(visitor);
+    visitor.visit(&m_form_data);
+}
+
+JS::Object* FormDataIterator::next()
+{
+    auto& vm = this->vm();
+
+    if (m_index >= m_form_data.m_entry_list.size())
+        return create_iterator_result_object(vm, JS::js_undefined(), true);
+
+    auto& entry = m_form_data.m_entry_list[m_index++];
+    if (m_iterator_kind == JS::Object::PropertyKind::Key)
+        return create_iterator_result_object(vm, JS::PrimitiveString::create(vm, entry.name), false);
+
+    auto entry_value = entry.value.visit(
+        [&](JS::Handle<FileAPI::File> const& file) -> JS::Value {
+            return file.cell();
+        },
+        [&](String const& string) -> JS::Value {
+            return JS::PrimitiveString::create(vm, string);
+        });
+
+    if (m_iterator_kind == JS::Object::PropertyKind::Value)
+        return create_iterator_result_object(vm, entry_value, false);
+
+    return create_iterator_result_object(vm, JS::Array::create_from(realm(), { JS::PrimitiveString::create(vm, entry.name), entry_value }), false);
+}
+
+}

Userland/Libraries/LibWeb/XHR/FormDataIterator.h

@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2023, Kenneth Myhra <kennethmyhra@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibWeb/Bindings/PlatformObject.h>
+#include <LibWeb/XHR/FormData.h>
+
+namespace Web::XHR {
+
+class FormDataIterator : public Bindings::PlatformObject {
+    WEB_PLATFORM_OBJECT(FormDataIterator, Bindings::PlatformObject);
+
+public:
+    static WebIDL::ExceptionOr<JS::NonnullGCPtr<FormDataIterator>> create(FormData const&, JS::Object::PropertyKind iterator_kind);
+
+    virtual ~FormDataIterator() override;
+
+    JS::Object* next();
+
+private:
+    FormDataIterator(FormData const&, JS::Object::PropertyKind iterator_kind);
+
+    virtual JS::ThrowCompletionOr<void> initialize(JS::Realm&) override;
+    virtual void visit_edges(Cell::Visitor&) override;
+
+    FormData const& m_form_data;
+    JS::Object::PropertyKind m_iterator_kind;
+    size_t m_index { 0 };
+};
+
+}

Userland/Libraries/LibWeb/idl_files.cmake

@@ -203,7 +203,7 @@ libweb_js_bindings(WebGL/WebGLContextEvent)
 libweb_js_bindings(WebGL/WebGLRenderingContext)
 libweb_js_bindings(WebIDL/DOMException)
 libweb_js_bindings(WebSockets/WebSocket)
-libweb_js_bindings(XHR/FormData)
+libweb_js_bindings(XHR/FormData ITERABLE)
 libweb_js_bindings(XHR/ProgressEvent)
 libweb_js_bindings(XHR/XMLHttpRequest)
 libweb_js_bindings(XHR/XMLHttpRequestEventTarget)