Using TFrameBrowser
lazarus / 38-Networking and Web Programming

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eric · 2013-05-22 19:03

Could someone please help me to get started with using TFrameBrowser
to display a remote web page. I've looked at various examples and
demos, but they're all quite complicated and it's difficult to reduce
them to the essentials. I've got as far as this:

Code: [Select]unit Unit1;

{$mode objfpc}{$H+}

interface

uses
  Classes, SysUtils, FileUtil, Forms, Controls, Graphics,
  Dialogs, StdCtrls, ExtCtrls, Buttons, FramBrwz, htmlview;

type

  { TForm1 }

  TForm1 = class(TForm)
    BitBtn1: TBitBtn;
    FrameBrowser1: TFrameBrowser;
    procedure BitBtn1Click(Sender: TObject);
    procedure FrameBrowser1GetPostRequestEx(Sender: TObject; IsGet:
boolean;
      const URL, Query, EncType, Referer: string; Reload: boolean;
      var NewURL: string; var DocType: ThtmlFileType; var Stream:
TMemoryStream
      );

  private
    { private declarations }
  public
    { public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.lfm}

{ TForm1 }

procedure TForm1.BitBtn1Click(Sender: TObject);
begin
   FrameBrowser1.LoadURL(<Remote URL>);
end;

procedure TForm1.FrameBrowser1GetPostRequestEx(Sender: TObject; IsGet:
boolean;
  const URL, Query, EncType, Referer: string; Reload: boolean;
  var NewURL: string; var DocType: ThtmlFileType; var Stream:
TMemoryStream);
begin

end;

end.

I presume that the data is in the stream, but what do I do with it?

----------------------------------------------------------------------
eric · 2013-05-23 14:59

If anyone is interested, I've worked out the basics. I use httpsend
(part of Synapse) to download the web page as a stream, and copy it to
the TFrameBrowser stream. The following code works with a very simple
page:

Code: [Select]unit Unit1;

{$mode objfpc}{$H+}

interface

uses
  Classes, SysUtils, FileUtil, Forms, Controls, Graphics,
  Dialogs, StdCtrls, ExtCtrls, Buttons, FramBrwz, htmlview, httpsend;

type

  { TForm1 }

  TForm1 = class(TForm)
    BitBtn1: TBitBtn;
    FrameBrowser1: TFrameBrowser;
    procedure BitBtn1Click(Sender: TObject);
    procedure FrameBrowser1GetPostRequestEx(Sender: TObject; IsGet:
boolean;
      const URL, Query, EncType, Referer: string; Reload: boolean;
      var NewURL: string; var DocType: ThtmlFileType; var Stream:
TMemoryStream
      );

  private
    { private declarations }
  public
    { public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.lfm}

{ TForm1 }

procedure TForm1.BitBtn1Click(Sender: TObject);
begin
  FrameBrowser1.LoadURL(<Remote URL>);
end;

procedure TForm1.FrameBrowser1GetPostRequestEx(Sender: TObject; IsGet:
boolean;
  const URL, Query, EncType, Referer: string; Reload: boolean;
  var NewURL: string; var DocType: ThtmlFileType; var Stream:
TMemoryStream);
var
  S: string;
  N: Integer;
  HTTPClient: THTTPsend;
begin
  S := URL;
  N := Pos('http://', S);
  if N = 1 then  //Remove prefix
  begin
    S := S[8..Length(S)];
  end;
  Stream := TMemoryStream.Create;
  HTTPClient := THTTPSend.Create;
  HTTPClient.Timeout := 5000;
  try
    if HTTPClient.HTTPMethod('GET', S) then
    begin
      Stream.CopyFrom(HTTPClient.Document, HTTPClient.Document.Size);
    end;
  finally
    HTTPClient.Free;
  end;
end;

end.

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Jurassic Pork · 2013-05-24 05:04

hello eric,
are you on windows , linux , both, others ?
what kind of web pages would you display ? don't forget that now often
web pages have javascript scripts. For this you need an "embedded"
browser  : geckport or chromiumembedded  for example. If you are on
windows it is more easy with activex and internet explorer.

Friendly, J.P

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eric · 2013-05-24 06:46

Hello JP

I develop on Linux, but I build for both Linux and Windows. For my
purpose here I only needed very basic browser capabilities, to enable
my program to collect some data from a specially written page on my
own website. The solution above is working well now.

----------------------------------------------------------------------
Pancratius · 2014-06-02 19:09

Quote from: eric on May 23, 2013, 04:59:25 pmIf anyone is interested,
I've worked out the basics. I use httpsend (part of Synapse) to
download the web page as a stream, and copy it to the TFrameBrowser
stream. The following code works with a very simple page:

Code: [Select]unit Unit1;

{$mode objfpc}{$H+}

interface

uses
  Classes, SysUtils, FileUtil, Forms, Controls, Graphics,
  Dialogs, StdCtrls, ExtCtrls, Buttons, FramBrwz, htmlview, httpsend;

type

  { TForm1 }

  TForm1 = class(TForm)
    BitBtn1: TBitBtn;
    FrameBrowser1: TFrameBrowser;
    procedure BitBtn1Click(Sender: TObject);
    procedure FrameBrowser1GetPostRequestEx(Sender: TObject; IsGet:
boolean;
      const URL, Query, EncType, Referer: string; Reload: boolean;
      var NewURL: string; var DocType: ThtmlFileType; var Stream:
TMemoryStream
      );

  private
    { private declarations }
  public
    { public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.lfm}

{ TForm1 }

procedure TForm1.BitBtn1Click(Sender: TObject);
begin
  FrameBrowser1.LoadURL(<Remote URL>);
end;

procedure TForm1.FrameBrowser1GetPostRequestEx(Sender: TObject; IsGet:
boolean;
  const URL, Query, EncType, Referer: string; Reload: boolean;
  var NewURL: string; var DocType: ThtmlFileType; var Stream:
TMemoryStream);
var
  S: string;
  N: Integer;
  HTTPClient: THTTPsend;
begin
  S := URL;
  N := Pos('http://', S);
  if N = 1 then  //Remove prefix
  begin
    S := S[8..Length(S)];
  end;
  Stream := TMemoryStream.Create;
  HTTPClient := THTTPSend.Create;
  HTTPClient.Timeout := 5000;
  try
    if HTTPClient.HTTPMethod('GET', S) then
    begin
      Stream.CopyFrom(HTTPClient.Document, HTTPClient.Document.Size);
    end;
  finally
    HTTPClient.Free;
  end;
end;

end.The code does not work. TFrameBrowser has to do something with the
returning stream generated by the HTTPclient.