LibWeb: Generate Element bindings from IDL :^)

Had to do a bunch more hacking on WrapperGenerator to support this.
We now support attribute setters as well.

7 files changed, 103 insertions, 289 deletions

diff --git a/Libraries/LibWeb/Bindings/ElementWrapper.cpp b/Libraries/LibWeb/Bindings/ElementWrapper.cpp
deleted file mode 100644
index 1fca778af3..0000000000
--- a/Libraries/LibWeb/Bindings/ElementWrapper.cpp
+++ /dev/null
@@ -1,157 +0,0 @@
-/*
- * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- *
- * 1. Redistributions of source code must retain the above copyright notice, this
- *    list of conditions and the following disclaimer.
- *
- * 2. Redistributions in binary form must reproduce the above copyright notice,
- *    this list of conditions and the following disclaimer in the documentation
- *    and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
- * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
- * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
- * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
- * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
- * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#include <AK/FlyString.h>
-#include <AK/Function.h>
-#include <LibJS/Interpreter.h>
-#include <LibJS/Runtime/Error.h>
-#include <LibJS/Runtime/GlobalObject.h>
-#include <LibJS/Runtime/PrimitiveString.h>
-#include <LibJS/Runtime/Value.h>
-#include <LibWeb/Bindings/ElementWrapper.h>
-#include <LibWeb/DOM/AttributeNames.h>
-#include <LibWeb/DOM/Element.h>
-
-namespace Web {
-namespace Bindings {
-
-ElementWrapper::ElementWrapper(JS::GlobalObject& global_object, Element& element)
-    : NodeWrapper(global_object, element)
-{
-}
-
-void ElementWrapper::initialize(JS::Interpreter& interpreter, JS::GlobalObject& global_object)
-{
-    NodeWrapper::initialize(interpreter, global_object);
-
-    define_native_property("innerHTML", inner_html_getter, inner_html_setter);
-    define_native_property("id", id_getter, id_setter);
-
-    u8 attributes = JS::Attribute::Configurable | JS::Attribute::Enumerable | JS::Attribute::Writable;
-    define_native_function("getAttribute", get_attribute, 1, attributes);
-    define_native_function("setAttribute", set_attribute, 2, attributes);
-}
-
-ElementWrapper::~ElementWrapper()
-{
-}
-
-Element& ElementWrapper::node()
-{
-    return static_cast<Element&>(NodeWrapper::impl());
-}
-
-const Element& ElementWrapper::node() const
-{
-    return static_cast<const Element&>(NodeWrapper::impl());
-}
-
-static Element* impl_from(JS::Interpreter& interpreter, JS::GlobalObject& global_object)
-{
-    auto* this_object = interpreter.this_value(global_object).to_object(interpreter, global_object);
-    if (!this_object)
-        return nullptr;
-    // FIXME: Verify that it's an ElementWrapper somehow!
-    return &static_cast<ElementWrapper*>(this_object)->node();
-}
-
-JS_DEFINE_NATIVE_FUNCTION(ElementWrapper::get_attribute)
-{
-    auto* impl = impl_from(interpreter, global_object);
-    if (!impl)
-        return {};
-
-    if (interpreter.argument_count() < 1)
-        return interpreter.throw_exception<JS::TypeError>(JS::ErrorType::BadArgCountOne, "getAttribute");
-
-    auto attribute_name = interpreter.argument(0).to_string(interpreter);
-    if (interpreter.exception())
-        return {};
-
-    auto attribute_value = impl->attribute(attribute_name);
-    if (attribute_value.is_null())
-        return JS::js_null();
-
-    return JS::js_string(interpreter, attribute_value);
-}
-
-JS_DEFINE_NATIVE_FUNCTION(ElementWrapper::set_attribute)
-{
-    auto* impl = impl_from(interpreter, global_object);
-    if (!impl)
-        return {};
-
-    if (interpreter.argument_count() < 2)
-        return interpreter.throw_exception<JS::TypeError>(JS::ErrorType::BadArgCountMany, "setAttribute", "two");
-
-    auto attribute_name = interpreter.argument(0).to_string(interpreter);
-    if (interpreter.exception())
-        return {};
-
-    auto attribute_value = interpreter.argument(1).to_string(interpreter);
-    if (interpreter.exception())
-        return {};
-
-    impl->set_attribute(attribute_name, attribute_value);
-    return JS::js_undefined();
-}
-
-JS_DEFINE_NATIVE_GETTER(ElementWrapper::inner_html_getter)
-{
-    if (auto* impl = impl_from(interpreter, global_object))
-        return JS::js_string(interpreter, impl->inner_html());
-    return {};
-}
-
-JS_DEFINE_NATIVE_SETTER(ElementWrapper::inner_html_setter)
-{
-    if (auto* impl = impl_from(interpreter, global_object)) {
-        auto string = value.to_string(interpreter);
-        if (interpreter.exception())
-            return;
-        impl->set_inner_html(string);
-    }
-}
-
-JS_DEFINE_NATIVE_GETTER(ElementWrapper::id_getter)
-{
-    if (auto* impl = impl_from(interpreter, global_object))
-        return JS::js_string(interpreter, impl->attribute(HTML::AttributeNames::id));
-    return {};
-}
-
-JS_DEFINE_NATIVE_SETTER(ElementWrapper::id_setter)
-{
-    if (auto* impl = impl_from(interpreter, global_object)) {
-        auto string = value.to_string(interpreter);
-        if (interpreter.exception())
-            return;
-        impl->set_attribute(HTML::AttributeNames::id, string);
-    }
-}
-
-}
-}
diff --git a/Libraries/LibWeb/Bindings/ElementWrapper.h b/Libraries/LibWeb/Bindings/ElementWrapper.h
deleted file mode 100644
index b7e53d1247..0000000000
--- a/Libraries/LibWeb/Bindings/ElementWrapper.h
+++ /dev/null
@@ -1,57 +0,0 @@
-/*
- * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- *
- * 1. Redistributions of source code must retain the above copyright notice, this
- *    list of conditions and the following disclaimer.
- *
- * 2. Redistributions in binary form must reproduce the above copyright notice,
- *    this list of conditions and the following disclaimer in the documentation
- *    and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
- * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
- * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
- * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
- * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
- * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#pragma once
-
-#include <LibWeb/Bindings/NodeWrapper.h>
-
-namespace Web {
-namespace Bindings {
-
-class ElementWrapper : public NodeWrapper {
-public:
-    ElementWrapper(JS::GlobalObject&, Element&);
-    virtual void initialize(JS::Interpreter&, JS::GlobalObject&) override;
-    virtual ~ElementWrapper() override;
-
-    Element& node();
-    const Element& node() const;
-
-private:
-    virtual const char* class_name() const override { return "ElementWrapper"; }
-
-    JS_DECLARE_NATIVE_GETTER(inner_html_getter);
-    JS_DECLARE_NATIVE_SETTER(inner_html_setter);
-
-    JS_DECLARE_NATIVE_GETTER(id_getter);
-    JS_DECLARE_NATIVE_SETTER(id_setter);
-
-    JS_DECLARE_NATIVE_FUNCTION(get_attribute);
-    JS_DECLARE_NATIVE_FUNCTION(set_attribute);
-};
-
-}
-}
diff --git a/Libraries/LibWeb/Bindings/Wrapper.h b/Libraries/LibWeb/Bindings/Wrapper.h
index 24c288b01c..09d9a6b5cb 100644
--- a/Libraries/LibWeb/Bindings/Wrapper.h
+++ b/Libraries/LibWeb/Bindings/Wrapper.h
@@ -40,6 +40,7 @@ class Wrapper
 public:
     virtual bool is_node_wrapper() const { return false; }
     virtual bool is_document_wrapper() const { return false; }
+    virtual bool is_element_wrapper() const { return false; }
 
 protected:
     explicit Wrapper(Object& prototype)
diff --git a/Libraries/LibWeb/CMakeLists.txt b/Libraries/LibWeb/CMakeLists.txt
index 3772bad89a..5131892522 100644
--- a/Libraries/LibWeb/CMakeLists.txt
+++ b/Libraries/LibWeb/CMakeLists.txt
@@ -3,6 +3,7 @@ set(SOURCES
     Bindings/DocumentWrapper.cpp
     Bindings/DocumentWrapper.h
     Bindings/ElementWrapper.cpp
+    Bindings/ElementWrapper.h
     Bindings/EventListenerWrapper.cpp
     Bindings/EventTargetWrapper.cpp
     Bindings/EventWrapper.cpp
@@ -126,45 +127,29 @@ set(GENERATED_SOURCES
     ../../Services/ProtocolServer/ProtocolServerEndpoint.h
 )
 
-add_custom_command(
-    OUTPUT Bindings/NodeWrapper.h
-    COMMAND /bin/mkdir -p Bindings
-    COMMAND WrapperGenerator --header ${CMAKE_CURRENT_SOURCE_DIR}/DOM/Node.idl > Bindings/NodeWrapper.h
-    VERBATIM
-    DEPENDS WrapperGenerator
-    MAIN_DEPENDENCY DOM/Node.idl
-)
-add_custom_target(generate_NodeWrapper.h DEPENDS Bindings/NodeWrapper.h)
-
-add_custom_command(
-    OUTPUT Bindings/NodeWrapper.cpp
-    COMMAND /bin/mkdir -p Bindings
-    COMMAND WrapperGenerator --implementation ${CMAKE_CURRENT_SOURCE_DIR}/DOM/Node.idl > Bindings/NodeWrapper.cpp
-    VERBATIM
-    DEPENDS WrapperGenerator
-    MAIN_DEPENDENCY DOM/Node.idl
-)
-add_custom_target(generate_NodeWrapper.cpp DEPENDS Bindings/NodeWrapper.cpp)
+function(libweb_js_wrapper class)
+    add_custom_command(
+        OUTPUT Bindings/${class}Wrapper.h
+        COMMAND /bin/mkdir -p Bindings
+        COMMAND WrapperGenerator --header ${CMAKE_CURRENT_SOURCE_DIR}/DOM/${class}.idl > Bindings/${class}Wrapper.h
+        VERBATIM
+        DEPENDS WrapperGenerator
+        MAIN_DEPENDENCY DOM/${class}.idl
+    )
+    add_custom_command(
+        OUTPUT Bindings/${class}Wrapper.cpp
+        COMMAND /bin/mkdir -p Bindings
+        COMMAND WrapperGenerator --implementation ${CMAKE_CURRENT_SOURCE_DIR}/DOM/${class}.idl > Bindings/${class}Wrapper.cpp
+        VERBATIM
+        DEPENDS WrapperGenerator
+        MAIN_DEPENDENCY DOM/${class}.idl
+    )
+    add_custom_target(generate_${class}Wrapper.h DEPENDS Bindings/${class}Wrapper.h)
+endfunction()
 
-add_custom_command(
-    OUTPUT Bindings/DocumentWrapper.h
-    COMMAND /bin/mkdir -p Bindings
-    COMMAND WrapperGenerator --header ${CMAKE_CURRENT_SOURCE_DIR}/DOM/Document.idl > Bindings/DocumentWrapper.h
-    VERBATIM
-    DEPENDS WrapperGenerator
-    MAIN_DEPENDENCY DOM/Document.idl
-)
-add_custom_target(generate_DocumentWrapper.h DEPENDS Bindings/DocumentWrapper.h)
-
-add_custom_command(
-    OUTPUT Bindings/DocumentWrapper.cpp
-    COMMAND /bin/mkdir -p Bindings
-    COMMAND WrapperGenerator --implementation ${CMAKE_CURRENT_SOURCE_DIR}/DOM/Document.idl > Bindings/DocumentWrapper.cpp
-    VERBATIM
-    DEPENDS WrapperGenerator
-    MAIN_DEPENDENCY DOM/Document.idl
-)
-add_custom_target(generate_DocumentWrapper.cpp DEPENDS Bindings/DocumentWrapper.cpp)
+libweb_js_wrapper(Node)
+libweb_js_wrapper(Document)
+libweb_js_wrapper(Element)
 
 add_custom_command(
     OUTPUT CSS/PropertyID.h
diff --git a/Libraries/LibWeb/CodeGenerators/WrapperGenerator.cpp b/Libraries/LibWeb/CodeGenerators/WrapperGenerator.cpp
index a1dcd0b860..24c32f70bc 100644
--- a/Libraries/LibWeb/CodeGenerators/WrapperGenerator.cpp
+++ b/Libraries/LibWeb/CodeGenerators/WrapperGenerator.cpp
@@ -34,15 +34,17 @@ static String snake_name(const StringView& title_name)
 {
     StringBuilder builder;
     bool first = true;
+    bool last_was_uppercase = false;
     for (auto ch : title_name) {
         if (isupper(ch)) {
-            if (!first)
+            if (!first && !last_was_uppercase)
                 builder.append('_');
             builder.append(tolower(ch));
         } else {
             builder.append(ch);
         }
         first = false;
+        last_was_uppercase = isupper(ch);
     }
     return builder.to_string();
 }
@@ -93,20 +95,6 @@ struct Interface {
     String wrapper_base_class;
 };
 
-static String snake_name(const StringView& camel_name)
-{
-    StringBuilder builder;
-    for (auto ch : camel_name) {
-        if (isupper(ch)) {
-            builder.append('_');
-            builder.append(tolower(ch));
-        } else {
-            builder.append(ch);
-        }
-    }
-    return builder.to_string();
-}
-
 OwnPtr<Interface> parse_interface(const StringView& input)
 {
     auto interface = make<Interface>();
@@ -422,9 +410,55 @@ void generate_implementation(const IDL::Interface& interface)
     out() << "    return &static_cast<" << wrapper_class << "*>(this_object)->impl();";
     out() << "}";
 
+    auto generate_to_cpp = [&](auto& parameter, auto& js_name, auto& js_suffix, auto cpp_name, bool return_void = false) {
+        auto generate_return = [&] {
+            if (return_void)
+                out() << "        return;";
+            else
+                out() << "        return {};";
+        };
+        if (parameter.type.name == "DOMString") {
+            out() << "    auto " << cpp_name << " = " << js_name << js_suffix << ".to_string(interpreter);";
+            out() << "    if (interpreter.exception())";
+            generate_return();
+        } else if (parameter.type.name == "Node") {
+            out() << "    auto " << cpp_name << "_object = " << js_name << js_suffix << ".to_object(interpreter, global_object);";
+            out() << "    if (interpreter.exception())";
+            generate_return();
+            auto is_foo_wrapper_name = snake_name(String::format("Is%sWrapper", parameter.type.name.characters()));
+            out() << "    if (!" << cpp_name << "_object->is_web_wrapper() || !static_cast<Wrapper*>(" << cpp_name << "_object)->" << is_foo_wrapper_name << "()) {";
+            out() << "        interpreter.throw_exception<JS::TypeError>(JS::ErrorType::NotA, \"" << parameter.type.name << "\");";
+            generate_return();
+            out() << "    }";
+            out() << "    auto& " << cpp_name << " = static_cast<" << parameter.type.name << "Wrapper*>(" << cpp_name << "_object)->impl();";
+        }
+    };
+
+    auto generate_arguments = [&](auto& parameters, auto& arguments_builder, bool return_void = false) {
+        Vector<String> parameter_names;
+        size_t argument_index = 0;
+        for (auto& parameter : parameters) {
+            parameter_names.append(snake_name(parameter.name));
+            out() << "    auto arg" << argument_index << " = interpreter.argument(" << argument_index << ");";
+            generate_to_cpp(parameter, "arg", argument_index, snake_name(parameter.name), return_void);
+            ++argument_index;
+        }
+
+        arguments_builder.join(", ", parameter_names);
+    };
+
     auto generate_return_statement = [&](auto& return_type) {
+        if (return_type.name == "void") {
+            out() << "    return JS::js_undefined();";
+            return;
+        }
+
         if (return_type.nullable) {
-            out() << "    if (!retval)";
+            if (return_type.name == "DOMString") {
+                out() << "    if (retval.is_null())";
+            } else {
+                out() << "    if (!retval)";
+            }
             out() << "        return JS::js_null();";
         }
 
@@ -445,7 +479,7 @@ void generate_implementation(const IDL::Interface& interface)
 
     // Implementation: Attributes
     for (auto& attribute : interface.attributes) {
-        out() << "JS_DEFINE_NATIVE_GETTER(" << wrapper_class << "::" << snake_name(attribute.name) << "_getter)";
+        out() << "JS_DEFINE_NATIVE_GETTER(" << wrapper_class << "::" << attribute.getter_callback_name << ")";
         out() << "{";
         out() << "    auto* impl = impl_from(interpreter, global_object);";
         out() << "    if (!impl)";
@@ -453,6 +487,19 @@ void generate_implementation(const IDL::Interface& interface)
         out() << "    auto retval = impl->" << snake_name(attribute.name) << "();";
         generate_return_statement(attribute.type);
         out() << "}";
+
+        if (!attribute.readonly) {
+            out() << "JS_DEFINE_NATIVE_SETTER(" << wrapper_class << "::" << attribute.setter_callback_name << ")";
+            out() << "{";
+            out() << "    auto* impl = impl_from(interpreter, global_object);";
+            out() << "    if (!impl)";
+            out() << "        return;";
+
+            generate_to_cpp(attribute, "value", "", "cpp_value", true);
+
+            out() << "    impl->set_" << snake_name(attribute.name) << "(cpp_value);";
+            out() << "}";
+        }
     }
 
     // Implementation: Functions
@@ -465,27 +512,8 @@ void generate_implementation(const IDL::Interface& interface)
         out() << "    if (interpreter.argument_count() < " << function.length() << ")";
         out() << "        return interpreter.throw_exception<JS::TypeError>(JS::ErrorType::BadArgCountMany, \"" << function.name << "\", \"" << function.length() << "\");";
 
-        Vector<String> parameter_names;
-        size_t argument_index = 0;
-        for (auto& parameter : function.parameters) {
-            parameter_names.append(snake_name(parameter.name));
-            if (parameter.type.name == "DOMString") {
-                out() << "    auto " << snake_name(parameter.name) << " = interpreter.argument(" << argument_index << ").to_string(interpreter);";
-                out() << "    if (interpreter.exception())";
-                out() << "        return {};";
-            } else if (parameter.type.name == "Node") {
-                out() << "    auto " << snake_name(parameter.name) << "_object = interpreter.argument(" << argument_index << ").to_object(interpreter, global_object);";
-                out() << "    if (interpreter.exception())";
-                out() << "        return {};";
-                out() << "    if (!" << snake_name(parameter.name) << "_object->is_web_wrapper() || !static_cast<Wrapper*>(" << snake_name(parameter.name) << "_object)->is_node_wrapper())";
-                out() << "        return interpreter.throw_exception<JS::TypeError>(JS::ErrorType::NotA, \"" << parameter.type.name << "\");";
-                out() << "    auto& " << snake_name(parameter.name) << " = static_cast<" << wrapper_class << "*>(" << snake_name(parameter.name) << "_object)->impl();";
-            }
-            ++argument_index;
-        }
-
         StringBuilder arguments_builder;
-        arguments_builder.join(", ", parameter_names);
+        generate_arguments(function.parameters, arguments_builder);
 
         if (function.return_type.name != "void") {
             out() << "    auto retval = impl->" << snake_name(function.name) << "(" << arguments_builder.to_string() << ");";
diff --git a/Libraries/LibWeb/DOM/Element.h b/Libraries/LibWeb/DOM/Element.h
index 547b6b21e3..70f93dbdc5 100644
--- a/Libraries/LibWeb/DOM/Element.h
+++ b/Libraries/LibWeb/DOM/Element.h
@@ -50,6 +50,7 @@ public:
 
     bool has_attribute(const FlyString& name) const { return !attribute(name).is_null(); }
     String attribute(const FlyString& name) const;
+    String get_attribute(const FlyString& name) const { return attribute(name); }
     void set_attribute(const FlyString& name, const String& value);
 
     void set_attributes(Vector<Attribute>&&);
@@ -80,6 +81,9 @@ public:
     String inner_html() const;
     void set_inner_html(StringView);
 
+    String id() const { return attribute(HTML::AttributeNames::id); }
+    void set_id(const String& value) { set_attribute(HTML::AttributeNames::id, value); }
+
 protected:
     RefPtr<LayoutNode> create_layout_node(const StyleProperties* parent_style) const override;
 
diff --git a/Libraries/LibWeb/DOM/Element.idl b/Libraries/LibWeb/DOM/Element.idl
new file mode 100644
index 0000000000..af914db646
--- /dev/null
+++ b/Libraries/LibWeb/DOM/Element.idl
@@ -0,0 +1,10 @@
+interface Element : Node {
+
+    DOMString? getAttribute(DOMString qualifiedName);
+    void setAttribute(DOMString qualifiedName, DOMString value);
+
+    attribute DOMString innerHTML;
+    attribute DOMString id;
+
+}
+