Rendering binary data from byte stream

[frontier]

Hello?

Can CefFrame renders a data(html, img, pdf, ...) from byte stream?
(Byte stream handles local data, not from the web.)
When I use LoadString method, html was well rendered, but img/pdf was crashed. And I think LoadRequest cannot be answer.

Does anybody knows how to render a binary data to cef browser?

[amaitland]

Implement 'CefRequestHandler::GetResourceHandler`, if the request Url matches you return a stream. Instead of calling LoadString you call LoadURL with your dummy url.

There's sample code in `cefclient` see
https://bitbucket.org/chromiumembedded/ ... ter#cl-465

[frontier]

Thank you! It could be very helpful!

[frontier]

I have another problem.

The document what I want to load has "EUC-KR" charset.
But when I load this document with GetResourceHandler method, CEF application always read it with default charset(UTF-8) so rendered document broken.

And can I control response header with CefStreamResourceHandler method's headerMap argument?
I've already try this but it seems to useless.

Why this problem happens?

[amaitland]

What does your code look like?

You can of course change the browsers default encoding if you wish see apidocs3/projects/%28default%29/_cef_browser_settings_t.html#default_encoding

You may well be able to set a response header. Searching this forum and you'll likely find something.

The other approach I've used previously is to prepend the preamble (encoding) to the beginning of the stream. (I've done this on c#, not sure how you'd implement this in c++)

[frontier]

Below is my implementaion.

Code: Select all

CefRefPtr<CefResourceHandler> MyHandler::GetResourceHandler(CefRefPtr<CefBrowser> browser, CefRefPtr<CefFrame> frame, CefRefPtr<CefRequest> request) {
  CEF_REQUIRE_UI_THREAD();
  if (frame->IsMain() && request->GetURL().ToString() == request_url_) {
    CefRefPtr<CefStreamReader> stream = CefStreamReader::CreateForData(static_cast<void*>(_html), _htmlSize);
    CefResponse::HeaderMap headermap;
    headermap.insert(std::make_pair("Content-Type", request_content_type_));
    return new CefStreamResourceHandler(200, CefString("OK"), request_mime_, headermap, stream);
  }
}


Of course I know there is command line option "--default-encoding", however, I expect CEF can read http header and change charset.

I just test some documents and found that CEF don't change charset by header Content-Type, but does change charset by meta tag. Is it right?

[amaitland]

Try accept-charset instead.

[frontier]

Thank you for answer.
To tell the result, "Accept-Charset" header did not affect.

I implement OnBeforeResourceLoad method like this

Code: Select all

bool MyHandler::OnBeforeResourceLoad(CefRefPtr<CefBrowser> browser, CefRefPtr<CefFrame> frame, CefRefPtr<CefRequest> request) {
  CEF_REQUIRE_UI_THREAD();
  CefRequest::HeaderMap headermap;
  request->GetHeaderMap(headermap);
  headermap.erase("Accept-Charset");
  headermap.insert(std::make_pair("Accept-Charset", "UTF-8"));
  request->SetHeaderMap(headermap);
  ...
  return false;
}


And I tried to print document.charset at rendered local document.

Code: Select all

console.log(document.charset);


Below is console result

Code: Select all

[0629/111828:INFO:CONSOLE(139)] "ISO-8859-1", source:  (139)


Rendered local document is absolutely same with google's main page(https://www.google.co.kr/).
I have no idea why this happened T.T

[frontier]

When load local document with CefStreamResourceHandler and user-defined headerMap, CEF does not change it's default charset to user-defined charset.
But load remote document, CEF does change it's charset to http header's charset.
It means CEF read http header but don't read user-defined response headerMap.

Is there a way let CEF to read http header by CefStreamResourceHandler?

* I'm using CEF 2171 build and centos 7 OS.

[amaitland]

Sounds like a bug. Might be worth checking the issue tracker to see if something similar has been reported already.