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 buttonif (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);