OnContextCreated in the subprocess-case not called

[OneLiner]

Hello CEF-forum,

I am in the middle of integrating cef into a mfc-application and i do actually face the problem, that
the virtual method OnContextCreated(CefRefPtr<CefBrowser> browser,CefRefPtr<CefFrame> frame,CefRefPtr<CefV8Context> context),
which gets overridden by my CefApp-derived class "MyCefApp" is NOT getting called at all.

MyCefApp indeed is derived from CefBrowserProcessHandler and from CefRenderProcessHandler,
and also contains the foll. lines in its header-file:

virtual CefRefPtr<CefBrowserProcessHandler> GetBrowserProcessHandler() OVERRIDE { return this; }
virtual CefRefPtr<CefRenderProcessHandler> GetRenderProcessHandler() OVERRIDE {return this;}
// CefBrowserProcessHandler methods:
virtual void OnContextInitialized() OVERRIDE;
== so MyCefApp declares/sets itself as BrowserProcessHandler / RenderProcessHandler.

I am loading a simple html-test-page, that should execute a small Javascript, which should result in a (alert()-) Message-Box being shown.
As i load the same html-test-page in the context of another smaller Test-CEF-application, i can exclude the possibility, that this html-test-page does contains an error.

The two applications are differing in the fact, that the one where OnContextCreated gets not called
uses the subprocess - approach.
CefString(&settings.browser_subprocess_path).FromASCII("SubProcessFactory.exe");

Transferring the subprocess - approach to the smaller Test-CEF-application (... where OnContextCreated was getting called before )
- everything else unchanged - the result was: OnContextCreated was not getting called anymore.

To me It seems, that using a subprocess prevents that OnContextCreated gets called.?!?
So my question is, what can i do, that OnContextCreated gets called using the subprocess-approach.

(We need to user the subprocess-approach...)

[magreenblatt]

How are you initializing CEF and running the message loop?

[OneLiner]

The initialization-code is like this:

bool MyApp::InitializeCef() {
// Initialize Chrome
m_CEFApp = new CefMfcCefApp;
CefMainArgs mainargs(GetModuleHandle(NULL));

// See if this is a Chrome process starting. If so, we're done with our (and MFC) initialization.
const auto exit_code = CefExecuteProcess(mainargs, m_CEFApp.get(), nullptr);
if (exit_code >= 0)
return false;

CefSettings settings;
settings.multi_threaded_message_loop = false;
settings.no_sandbox = true;
CefString(&settings.cache_path) = m_WorkDir;
CefString(&settings.browser_subprocess_path).FromASCII("MyCefStarter.exe");
return CefInitialize(mainargs, settings, m_CEFApp.get(), nullptr);
}

[magreenblatt]

You need to also run the message loop. See https://bitbucket.org/chromiumembedded/ ... ntegration

[OneLiner]

Well i do call the message-loop, like this:

BOOL MyApp::PumpMessage()
{
auto result = CWinAppEx::PumpMessage();

// If there are other messages on queue then return right away
// otherwise CEF has a habit of eating keystrokes not meant for it
MSG msg;
if (PeekMessage(&msg, NULL, 0, 0, PM_NOREMOVE))
return result;

// Allow Cef to do his thing
CefDoMessageLoopWork();

return result;
}

Since my html-test-page is successfully CEF-rendered, i suppose that i am doing it right.
But unfortunately, using the subprocess-case, the V8/Javascript related OnContextCreated-Method is not getting called...

[magreenblatt]

Since my html-test-page is successfully CEF-rendered, i suppose that i am doing it right.
But unfortunately, using the subprocess-case, the V8/Javascript related OnContextCreated-Method is not getting called...

OnContextCreated will be called in the renderer process. How is SubProcessFactory.exe implemented? How are you testing that the method is not getting called?

[OneLiner]

Maybe my comprehension was and still is wrong,
but SubProcessFactory.exe is only implemented like this:

Code: Select all

#include "stdafx.h"
#include "aDISCl_CefStarter.h"
#include "include/cef_base.h"
#include "include/cef_app.h"

class CefStarterApp : public CefApp {
public:
  CefStarterApp() {}

private:
  // Include the default reference counting implementation.
  IMPLEMENT_REFCOUNTING(CefStarterApp);
};

int APIENTRY wWinMain(_In_ HINSTANCE hInstance,
                     _In_opt_ HINSTANCE hPrevInstance,
                     _In_ LPWSTR    lpCmdLine,
                     _In_ int       nCmdShow){

  // Structure for passing command-line arguments.
  // The definition of this structure is platform-specific.
  CefMainArgs main_args(GetModuleHandle(NULL));

  // Optional implementation of the CefApp interface. 
  CefRefPtr<CefApp> app = new CefStarterApp();

  // Execute the sub-process logic. This will block until the sub-process should exit.
  return CefExecuteProcess(main_args, app.get(), nullptr);
}

/****************************************************************************************
Whereas our "main-application", the one we wanted to extend using CEF - actually uses this implementation:

Code: Select all

class CefMfcCefApp : public CefApp
  , public CefBrowserProcessHandler
  , public CefRenderProcessHandler {
public:
  CefMfcCefApp() {}

  // CefApp methods:
  virtual CefRefPtr<CefBrowserProcessHandler> GetBrowserProcessHandler() OVERRIDE { return this; }
  virtual CefRefPtr<CefRenderProcessHandler> GetRenderProcessHandler() OVERRIDE { return this; }

private:
  // Include the default reference counting implementation.
  IMPLEMENT_REFCOUNTING(CefMfcCefApp);
  CefRefPtr<CaClHtmlCEFClientHandler> m_cefHandler;
  CefRefPtr<CaClHtmlCEFV8_JavaScript_Handler>     m_V8_JavaScript_Handler;

public:
  // CefBrowserProcessHandler methods:
  virtual void OnContextInitialized() OVERRIDE;

  // CefRenderProcessHandler methods:
  virtual void OnContextCreated(CefRefPtr<CefBrowser> browser, CefRefPtr<CefFrame> frame, CefRefPtr<CefV8Context> context) OVERRIDE;
  virtual void OnContextReleased(CefRefPtr<CefBrowser> browser, CefRefPtr<CefFrame> frame, CefRefPtr<CefV8Context> context) OVERRIDE;
  virtual bool OnProcessMessageReceived(CefRefPtr<CefBrowser> browser, CefProcessId source_process, CefRefPtr<CefProcessMessage> message) OVERRIDE;

  // Astec methods:
  CefRefPtr<CefBrowser> CreateBrowser(CaClHtmlCEFClientHandler::Delegate* delegate, CefWindowInfo const & info, CefBrowserSettings const & settings, CefString const & url);
  void DetachDelegate(CaClHtmlCEFClientHandler::Delegate* pDelegate);
};


Do i have to move the CefRenderProcessHandler-related code to the CefStarterApp-class inside SubProcessFactory.exe?

[magreenblatt]

Do i have to move the CefRenderProcessHandler-related code to the CefStarterApp-class inside SubProcessFactory.exe?

Yes.

[OneLiner]

Thank you magreenblatt, that solved my problem.

[jeroenclarysse]

I feel like a doofus, but I can't get this to work

is there anyone who has a cefsimple folder in which this works ? Trying desperately to get C++ calls from javascript running so some sample code would be very very very appreciated (I don't know if these forums show email addresses ? )