extensions/renderer/utils_native_handler.cc

// 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.

#include "extensions/renderer/utils_native_handler.h"

#include "base/macros.h"
#include "base/strings/stringprintf.h"
#include "extensions/renderer/script_context.h"
#include "third_party/WebKit/public/web/WebSerializedScriptValue.h"

namespace extensions {

UtilsNativeHandler::UtilsNativeHandler(ScriptContext* context)
    : ObjectBackedNativeHandler(context) {
  RouteFunction("createClassWrapper",
                base::Bind(&UtilsNativeHandler::CreateClassWrapper,
                           base::Unretained(this)));
  RouteFunction(
      "deepCopy",
      base::Bind(&UtilsNativeHandler::DeepCopy, base::Unretained(this)));
}

UtilsNativeHandler::~UtilsNativeHandler() {}

void UtilsNativeHandler::CreateClassWrapper(
    const v8::FunctionCallbackInfo<v8::Value>& args) {
  CHECK_EQ(3, args.Length());
  CHECK(args[0]->IsString());
  std::string name = *v8::String::Utf8Value(args[0]);
  CHECK(args[1]->IsObject());
  v8::Local<v8::Object> cls = args[1].As<v8::Object>();
  CHECK(args[2]->IsObject() || args[2]->IsUndefined());
  v8::Local<v8::Value> superclass = args[2];

  v8::HandleScope handle_scope(GetIsolate());
  // TODO(fsamuel): Consider moving the source wrapping to ModuleSystem.
  v8::Local<v8::String> source = v8::String::NewFromUtf8(
      GetIsolate(),
      base::StringPrintf(
          "(function($Object, $Function, privates, cls, superclass) {"
          "'use strict';\n"
          "  function %s() {\n"
          "    var privateObj = $Object.create(cls.prototype);\n"
          "    $Function.apply(cls, privateObj, arguments);\n"
          "    privateObj.wrapper = this;\n"
          "    privates(this).impl = privateObj;\n"
          "  };\n"
          "  if (superclass) {\n"
          "    %s.prototype = Object.create(superclass.prototype);\n"
          "  }\n"
          "  return %s;\n"
          "})",
          name.c_str(), name.c_str(), name.c_str()).c_str());
  v8::Local<v8::Value> func_as_value = context()->module_system()->RunString(
      source, v8::String::NewFromUtf8(GetIsolate(), name.c_str()));
  if (func_as_value.IsEmpty() || func_as_value->IsUndefined()) {
    args.GetReturnValue().SetUndefined();
    return;
  }

  // TODO(fsamuel): Move privates from ModuleSystem to a shared location.
  v8::Local<v8::Object> natives(context()->module_system()->NewInstance());
  CHECK(!natives.IsEmpty());  // this can happen if v8 has issues

  v8::Local<v8::Function> func = func_as_value.As<v8::Function>();
  v8::Local<v8::Value> func_args[] = {
      context()->safe_builtins()->GetObjekt(),
      context()->safe_builtins()->GetFunction(),
      natives->Get(v8::String::NewFromUtf8(GetIsolate(), "privates",
                                           v8::String::kInternalizedString)),
      cls,
      superclass};
  v8::Local<v8::Value> result;
  {
    v8::TryCatch try_catch(GetIsolate());
    try_catch.SetCaptureMessage(true);
    result = context()->CallFunction(func, arraysize(func_args), func_args);
    if (try_catch.HasCaught()) {
      args.GetReturnValue().SetUndefined();
      return;
    }
  }
  args.GetReturnValue().Set(result);
}

void UtilsNativeHandler::DeepCopy(
    const v8::FunctionCallbackInfo<v8::Value>& args) {
  CHECK_EQ(1, args.Length());
  args.GetReturnValue().Set(
      blink::WebSerializedScriptValue::serialize(args[0]).deserialize());
}

}  // namespace extensions