Modify requestHeaders in "custom" browser in delphi

Question

I have a browser integrated in my deplhi application (IE). I need to call a certain web app and I need to append a new variable in the header for all the requests that come from my application's browser, like jquery adds to the xhrobj the HTTP_X_REQUESTED_WITH parameter. Any idea on how can I do that? code samples would be great. I am usin TWebBrowser.

Answer 1

You can modify the headers with the OnBeforeNavigate2 event:

procedure TForm1.WebBrowser1BeforeNavigate2(Sender: TObject;
  const pDisp: IDispatch; var URL, Flags, TargetFrameName, PostData,
  Headers: OleVariant; var Cancel: WordBool);
var
  NewHeaders: OleVariant;
begin
  // do not allow frames or iframes to raise this event
  if (pDisp as IUnknown) = (WebBrowser1.ControlInterface as IUnknown) then
  begin
    // avoid stack overflow: check if our custom header is already set
    if Pos('MyHeader', Headers) <> 0 then Exit;

    // cancel the current navigation
    Cancel := True;
    (pDisp as IWebBrowser2).Stop;

    // modify headers with our custom header
    NewHeaders := Headers + 'MyHeader: Value'#13#10;

    (pDisp as IWebBrowser2).Navigate2(URL, Flags, TargetFrameName, PostData, NewHeaders);
  end;
end;