Replacing WebUIBindings use of CPPBoundClass with v8::Extension.

content/renderer/web_ui_extension.cc

Index: content/renderer/web_ui_extension.cc
diff --git a/content/renderer/web_ui_extension.cc b/content/renderer/web_ui_extension.cc
new file mode 100644
index 0000000000000000000000000000000000000000..0dedd8fd04362d62056c2b3d92f68e39579551d9
--- /dev/null
+++ b/content/renderer/web_ui_extension.cc
@@ -0,0 +1,149 @@
+// Copyright (c) 2012 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 "content/renderer/web_ui_extension.h"
+
+#include "base/memory/scoped_ptr.h"
+#include "base/utf_string_conversions.h"
+#include "base/values.h"
+#include "content/common/view_messages.h"
+#include "content/public/common/bindings_policy.h"
+#include "content/public/common/url_constants.h"
+#include "content/public/renderer/render_thread.h"
+#include "content/public/renderer/render_view.h"
+#include "googleurl/src/gurl.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebDocument.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebFrame.h"
+#include "v8/include/v8.h"
+
+namespace {
+
+// Converts a V8 value to a UTF8 string.
+std::string V8ValueToUTF8(v8::Handle<v8::Value> v) {
+  v8::String::Value s(v);
+  string16 str16(reinterpret_cast<const char16*>(*s), s.length());
+  return UTF16ToUTF8(str16);
+}

[abarth-chromium, 2012/08/23 20:13:24]

We must already have this code elsewhere.  Can we share it?

[Shishir, 2012/11/06 20:08:38]

I cant find a common libaray that has these. I had created one in
content/common, but jam felt it was unnecessary to add this.

+
+Value* ConvertV8Value(v8::Handle<v8::Value> value) {
+  if (value->IsBoolean())
+    return Value::CreateBooleanValue(value->BooleanValue());
+  if (value->IsInt32())
+    return Value::CreateIntegerValue(value->Int32Value());
+  if (value->IsNumber())
+    return Value::CreateDoubleValue(value->NumberValue());
+  if (value->IsString() || value->IsStringObject())
+    return Value::CreateStringValue(V8ValueToUTF8(value));
+
+  if (value->IsObject() || value->IsArray()) {
+    // We currently assume all objects are arrays.
+    DCHECK(value->IsArray());
+
+    v8::Handle<v8::Array> arr = value.As<v8::Array>();
+    ListValue* list = new ListValue();
+    for (size_t i = 0; i < arr->Length(); ++i) {
+      v8::Handle<v8::Value> v = arr->Get(i);
+      list->Append(ConvertV8Value(v));
+    }
+    return list;
+  }
+
+  // Covers null and undefined.
+  return Value::CreateNullValue();
+}

[abarth-chromium, 2012/08/23 20:13:24]

ditto

[Shishir, 2012/11/06 20:08:38]

Found a converter that does this and replaced this code.

+
+}  // namespace
+
+namespace content {
+
+static const char* const kWebUIExtensionName = "v8/WebUI";
+
+static const char* const kWebUIExtensionJS =
+    "var chrome;"
+    "if (!chrome)"
+    "  chrome = {};"
+    "chrome.send = function(name, data) {"
+    "  native function Send();"
+    "  Send(name, data);"
+    "};";
+
+
+class WebUIExtensionWrapper : public v8::Extension {
+ public:
+  WebUIExtensionWrapper();
+  virtual ~WebUIExtensionWrapper();
+
+  virtual v8::Handle<v8::FunctionTemplate> GetNativeFunction(
+      v8::Handle<v8::String> name);
+  static v8::Handle<v8::Value> Send(const v8::Arguments& args);
+
+ private:
+
+  DISALLOW_COPY_AND_ASSIGN(WebUIExtensionWrapper);
+};
+
+WebUIExtensionWrapper::WebUIExtensionWrapper()
+    : v8::Extension(kWebUIExtensionName, kWebUIExtensionJS) { }
+
+WebUIExtensionWrapper::~WebUIExtensionWrapper() { }
+
+v8::Handle<v8::FunctionTemplate> WebUIExtensionWrapper::GetNativeFunction(
+    v8::Handle<v8::String> name) {
+  return name->Equals(v8::String::New("Send")) ?
+      v8::FunctionTemplate::New(Send) : v8::Handle<v8::FunctionTemplate>();
+}
+
+// static
+v8::Handle<v8::Value> WebUIExtensionWrapper::Send(const v8::Arguments& args) {
+  // The send function is only available to internal webui pages.
+  WebKit::WebFrame* frame = WebKit::WebFrame::frameForCurrentContext();
+  if (!frame || !frame->view())
+    return v8::Undefined();
+
+  content::RenderView* render_view =
+      content::RenderView::FromWebView(frame->view());
+  GURL frame_url = frame->document().url();
+
+  bool webui_enabled =
+      (render_view->GetEnabledBindings() & content::BINDINGS_POLICY_WEB_UI) &&
+      (frame_url.SchemeIs(chrome::kChromeUIScheme) ||
+       frame_url.SchemeIs(chrome::kDataScheme));

[abarth-chromium, 2012/08/23 20:13:24]

I see, the check went here.  That's not as good because it means the function
will be visible in JS---it just won't do anything.  Maybe that's ok though.  I'm
not sure which renderviews have BINDINGS_POLICY_WEB_UI

[Shishir, 2012/11/06 20:08:38]

The webuis all have this along with one exception I found - the ballonhost
stuff. looking at the definition of BINDINGS_POLICY_WEB_UI in
content/public/common/bindings_policy.h, it says 'HTML-based UI bindings that
allows the JS content to send JSON-encoded data back to the browser process.' So
I am not sure why the other schemeis checks are required. 

I am also not sure if we can expose the chrome.send eventhough it will not do
anything. Will let anyone else chime in.

+
+  if (!webui_enabled)
+    return v8::Undefined();
+
+  // We expect at least two parameters - a string message identifier, and
+  // an object parameter. The object param can be undefined.
+  if (args.Length() != 2 || !args[0]->IsString())
+    return v8::Undefined();
+
+  const std::string message = V8ValueToUTF8(args[0]);
+
+  // If they've provided an optional message parameter, convert that into a
+  // Value to send to the browser process.
+  scoped_ptr<Value> content;
+  if (args[1]->IsUndefined()) {
+    content.reset(new ListValue());
+  } else {
+    if (!args[1]->IsObject())
+      return v8::Undefined();
+
+    content.reset(ConvertV8Value(args[1]));
+    CHECK(content->IsType(Value::TYPE_LIST));
+  }
+
+  // Send the message up to the browser.
+  render_view->Send(new ViewHostMsg_WebUISend(
+      render_view->GetRoutingID(),
+      frame_url,
+      message,
+      *(static_cast<ListValue*>(content.get()))));
+  return v8::Undefined();
+}
+
+v8::Extension* WebUIExtension::Get() {
+  return new WebUIExtensionWrapper();
+}
+
+}  // namespace content