cef native C++ interaction with JS

I  do example based on cefclient project.

modify client_renderer.cc,  class ClientRenderDelegate implements CefV8Handler's interface Execute.

class ClientRenderDelegate : public ClientAppRenderer::Delegate, CefV8Handler

  virtual bool Execute(const CefString& name,
	  CefRefPtr<CefV8Value> object,
	  const CefV8ValueList& arguments,
	  CefRefPtr<CefV8Value>& retval,
	  CefString& exception) OVERRIDE {
	  if (name.compare("myfunc") == 0) {
		  // Return my string value.
		  retval = CefV8Value::CreateString("My Value!");
		  return true;
	  }
	  else  if (name.compare("registercb") == 0) {
		  if (arguments.size() == 1 && arguments[0]->IsFunction()) {
			  js_callback_ = arguments[0].get();
			  js_context_ = CefV8Context::GetCurrentContext();
		  }
		  return true;
	  }
	  // Function does not exist.
	  return false;
  }

JS  call native function

in ClientRenderDelegate  OnContextCreated(), register a function named myfun,

	// Retrieve the context's window object.
	CefRefPtr<CefV8Value> object = context->GetGlobal();

	// Create a new V8 string value. See the "Basic JS Types" section below.
	CefRefPtr<CefV8Value> str = CefV8Value::CreateString("My Value!");
	// Add the string to the window object as "window.myval". See the "JS Objects" section below.
	object->SetValue("myval", str, V8_PROPERTY_ATTRIBUTE_NONE);

	CefRefPtr<CefV8Handler> myhandler = this;
	CefRefPtr<CefV8Value> func = CefV8Value::CreateFunction("myfunc", myhandler);
	object->SetValue("myfunc", func, V8_PROPERTY_ATTRIBUTE_NONE);

myhandler is ClientRenderDelegate  object which inherite CefV8Handler, implements Execucte()

in JS,

<script>
   /*
  alert(window.myval);  // this is for object->SetValue("myval", str, V8_PROPERTY_ATTRIBUTE_NONE)                   
  */

alert(window.myfunc()); </script>

native call JS

in ClientRenderDelegate  OnContextCreated(), register a function named registercb,

	object->SetValue("registercb",
		CefV8Value::CreateFunction("registercb", myhandler),
		V8_PROPERTY_ATTRIBUTE_NONE); 

define 2 member val,

  CefRefPtr<CefV8Context>  js_context_;
  CefRefPtr<CefV8Value>  js_callback_;

in Execute(),  save JS function callback and render context.

in JS,

  function n2jFunc() {
         alert("native call js function");
   }
  window.registercb(n2jFunc);

in root_window_win.cc, replace reload button's method,

    case IDC_NAV_RELOAD:  // Reload button
		if (CefRefPtr<CefBrowser> browser = GetBrowser()) {
			//browser->Reload();		 
			{
				// Create the message object.
				CefRefPtr<CefProcessMessage> msg = CefProcessMessage::Create("calljs");

				// Retrieve the argument list object.
				CefRefPtr<CefListValue> args = msg->GetArgumentList();

				// Populate the argument values.
				args->SetString(0, "calljs");
				args->SetInt(0, 10);

				// Send the process message to the render process.
				// Use PID_BROWSER instead when sending a message to the browser process.
				browser->SendProcessMessage(PID_RENDERER, msg);
				_cwprintf(L" send mesage calljs  to render \n");
			}
	  }

Send a message calljs  from browser process to render process,

in  ClientRenderDelegate OnProcessMessageReceived(), run JS function n2jFunc()

	  const std::string& message_name = message->GetName();
	  // MessageBox(NULL, L" TEST", L"EditWndProc  receive message", MB_OK);
	  if (message_name == "calljs" ) {
		  //browser->GetMainFrame()->ExecuteJavaScript("alert('ExecuteJavaScript works!');",
			 // browser->GetMainFrame()->GetURL(), 0);
		  if (js_callback_) {
			  CefV8ValueList args;
			  CefString str = message->GetArgumentList()->GetString(0);
			  args.push_back(CefV8Value::CreateString(str));
			  args.push_back(CefV8Value::CreateInt(message->GetArgumentList()->GetInt(1)));
			  js_callback_->ExecuteFunctionWithContext(js_context_, NULL, args);
		  }
 
		  return true;
	  }
    return message_router_->OnProcessMessageReceived(browser, source_process,
                                                     message);