Capture values of an input in Delphi (Tchromium)

Question

Good morning,

I’m using HTML, CSS and Javascript to set up a chat layout for a messaging system I’m developing. Until then, everything ok, only due to a limitation problem I found in Twebbrowser, I migrated to Tchromium, the same made it easier for me in several aspects, however, I’m doubtful how I can be getting the values of an input in my HTML code. With Twebbrowser I used the following code arqID := Browser.OleObject.Document.All.Tags('input').item('arqID').value;

Does anyone know the equivalent function I used in Twebbrowser (Oleobject) in Tchromium?

@EDIT: I gave up trying to use this method to get the values, I was able to do what I wanted using the URL manipulation in the browser, and through a Chromium event that notices the URL change (Addresschange), I pull the current URL (Chromium1.Browser.MainFrame.Url;) and with the POS filter the values I want to take.

Answer 1

Create a js function that can be triggered by a click on a button or any other medium.

In Delphi you need to register an extension in the Browser. Ex.

type
  TCustomRenderProcessHandler = class(TCefRenderProcessHandlerOwn)
  protected
    procedure OnWebKitInitialized; override;
  end;

  TExtensao = class
    class procedure click(const data: string);
  end;

For class TExtensao note that we have a procedure called click, this will be the contact with the js function, we are creating nothing more or less than a System between Delphi and Browser.

Procedure click:

class procedure TExtensao.click(const data: string);
var
  vMensagem : ICefProcessMessage;
begin
  // Registra o Evento Click para a Extensão que criamos anteriormente
  vMensagem := TCefProcessMessageRef.New('click');
  vMensagem.ArgumentList.SetString(0, data);
  TCefv8ContextRef.Current.Browser.SendProcessMessage(PID_BROWSER, vMensagem);
end;

Now, we need to inform the system that on startup it captures the events of the Browser, then in the boot section add:

initialization 
...     
  // Inicializa virtualmente os Procedimentos externos do Navegador que no caso vai registrar o TExtension}
  CefRenderProcessHandler  := TCustomRenderProcessHandler.Create;
  CefBrowserProcessHandler := TCefBrowserProcessHandlerOwn.Create;

The component TChromium has an event called ProcessMessageReceived, here every time the Istener click is triggered in the Navigator informs TCustomRenderProcessHandler that we registered earlier that a new message has arrived.

You can filter events through the parameter message. something like:

if message.Name = 'click' then
  message.ArgumentList.GetString(0)

As his name says message.ArgumentList is a list of arguments sent by the Navigator, and at position 0 contains the result of the js function that was created to pick the values of the desired fields.

Edit.

Missing implementation of the app Registration:

{ TCustomRenderProcessHandler }
procedure TCustomRenderProcessHandler.OnWebKitInitialized;
begin
  // Registra uma Extensão chamada "app" para o evento "click"
  TCefRTTIExtension.Register('app', TExtensao);
end;