IDL: Generate union type containers

Source/bindings/templates/union.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// FIXME: Implement
+// This file has been auto-generated by {{code_generator}}. DO NOT MODIFY!
+
+#include "config.h"
+#include "{{header_filename}}"
+
+{% for filename in cpp_includes %}
+#include "{{filename}}"
+{% endfor %}
+
+namespace blink {
+
+{% for container in containers %}
+{{container.cpp_class}}::{{container.cpp_class}}()
+    : m_specificTypeFlag(0)
+{
+}
+
+{% for member in container.members %}
+{{member.rvalue_cpp_type}} {{container.cpp_class}}::getAs{{member.type_name}}()
+{
+    ASSERT(is{{member.type_name}}());
+    return m_{{member.cpp_name}};
+}
+
+void {{container.cpp_class}}::set{{member.type_name}}({{member.rvalue_cpp_type}} value)
+{
+    ASSERT(isNull());
+    m_{{member.cpp_name}} = value;
+    m_specificTypeFlag = {{member.index}};
+}
+
+{% endfor %}
+void V8{{container.cpp_class}}::toImpl(v8::Isolate* isolate, v8::Handle<v8::Value> v8Value, {{container.cpp_class}}& impl, ExceptionState& exceptionState)
+{
+    if (v8Value.IsEmpty() || isUndefinedOrNull(v8Value))

[Jens Widell, 2014/10/28 11:31:38]

Null or undefined isn't treated this way in the spec. A null or undefined value
should map to null if there's a nullable member type and otherwise be converted
into a dictionary type if there's such a member type, and otherwise throw a type
error.

If we don't want to follow the spec to the letter on that, then add a FIXME?

[bashi, 2014/10/29 01:34:33]

Yes, this is tentative, and I should have added a FIXME comment. Added. I'll
revise this in a follow-up CL.

+        return;
+
+    {# The numbers in the following comments refer the steps described in
+       http://heycam.github.io/webidl/#es-union
+       FIXME: Implement all necessary steps #}
+    {# 3. Platform objects (interfaces) #}
+    {% for platform_object in container.platform_objects %}
+    if (V8{{platform_object.type_name}}::hasInstance(v8Value, isolate)) {
+        {{platform_object.cpp_type}} cppValue = V8{{platform_object.type_name}}::toImplWithTypeCheck(isolate, v8Value);

[Jens Widell, 2014/10/28 11:31:38]

No need to use *WithTypeCheck() here; you just type-checked it. Use

  V8{{platform_object.cpp_type}} cppValue =
V8{{platform_object.cpp_type}}::toImpl(v8::Handle<v8::Object>::Cast(v8_value));

instead.

[bashi, 2014/10/29 01:34:32]

Done.

+        impl.set{{platform_object.type_name}}(cppValue);
+        return;
+    }
+
+    {% endfor %}
+    {% if container.dictionary_type %}
+    {# 12. Dictionaries #}
+    if (v8Value->IsObject()) {

[Jens Widell, 2014/10/28 11:31:38]

Spec says "object but not Date or RegExp". If we don't want to follow the spec
ehre for some reason, at least add a (FIXME) comment about the difference.

[bashi, 2014/10/29 01:34:33]

Added a FIXME comment.

+        {{container.dictionary_type.cpp_type}} cppValue = V8{{container.dictionary_type.type_name}}::toImpl(isolate, v8Value, exceptionState);
+        if (!exceptionState.hadException())
+            impl.set{{container.dictionary_type.type_name}}(cppValue);
+        return;
+    }
+
+    {% endif %}
+    {% if container.boolean_type %}
+    {# 14. Boolean #}
+    if (v8Value->IsBoolean()) {
+        impl.setBoolean(v8Value->ToBoolean()->Value());
+        return;
+    }
+
+    {% endif %}
+    {% if container.numeric_type %}
+    {# 15. Number #}
+    if (v8Value->IsNumber()) {

[Jens Widell, 2014/10/28 11:31:38]

You never convert to number (or boolean). If there's no string type, but there
is a number (or boolean) type, you should convert to number (or boolean) at the
end, rather than throwing a type error.

[bashi, 2014/10/29 01:34:32]

Good catch! Done.

+        {{container.numeric_type.v8_value_to_local_cpp_value}};
+        impl.set{{container.numeric_type.type_name}}(cppValue);
+        return;
+    }
+
+    {% endif %}
+    {% if container.string_type %}
+    {# 16. String #}
+    {
+        {{container.string_type.v8_value_to_local_cpp_value}};
+        impl.set{{container.string_type.type_name}}(cppValue);
+        return;
+    }
+
+    {% endif %}
+    {# 19. TypeError #}
+    exceptionState.throwTypeError("Not a valid union member.");
+}
+
+v8::Handle<v8::Value> toV8({{container.cpp_class}}& impl, v8::Handle<v8::Object> creationContext, v8::Isolate* isolate)
+{
+    if (impl.isNull())
+        return v8::Undefined(isolate);
+
+    {% for member in container.members %}
+    if (impl.is{{member.type_name}}())
+        return {{member.cpp_value_to_v8_value}};
+
+    {% endfor %}
+    ASSERT_NOT_REACHED();
+    return v8::Undefined(isolate);
+}
+
+{% endfor %}
+} // namespace blink