(Delphi ActiveX) HTTP Download to Stream

Demonstrates how to stream the response body directly to a stream, which in this case is to a file stream.

Chilkat for Delphi Downloads Chilkat ActiveX DLL for Delphi Chilkat non-ActiveX DLL for Delphi * The examples here use the ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_TLB;

...

procedure TForm1.Button1Click(Sender: TObject);
var
rest: TChilkatRest;
url: TChilkatUrl;
bAutoReconnect: Integer;
success: Integer;
responseStatusCode: Integer;
bodyStream: TChilkatStream;
errResponse: WideString;

begin
// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

rest := TChilkatRest.Create(Self);

// The URL we want to download is: 
// https://github.com/chilkatsoft/OAuth2-CSharp-Desktop/archive/master.zip
url := TChilkatUrl.Create(Self);
url.ParseUrl('https://github.com/chilkatsoft/OAuth2-CSharp-Desktop/archive/master.zip');

// Connect to the web server
bAutoReconnect := 1;
success := rest.Connect(url.Host,url.Port,url.Ssl,bAutoReconnect);
if (success <> 1) then
  begin
    Memo1.Lines.Add(rest.LastErrorText);
    Exit;
  end;

success := rest.SendReqNoBody('GET',url.Path);
if (success <> 1) then
  begin
    Memo1.Lines.Add(rest.LastErrorText);
    Exit;
  end;

// Read the response header.
responseStatusCode := rest.ReadResponseHeader();
if (responseStatusCode < 0) then
  begin
    Memo1.Lines.Add(rest.LastErrorText);
    Exit;
  end;

Memo1.Lines.Add('Response status code = ' + IntToStr(responseStatusCode));

// We expect a 200 response status if the file data is coming.
// Otherwise, we'll get a string response body with an error message(or no response body).
if (responseStatusCode = 200) then
  begin

    bodyStream := TChilkatStream.Create(Self);

    // The stream's sink will be a file.
    bodyStream.SinkFile := 'qa_output/OAuth2-CSharp-Desktop/archive/master.zip';

    // Read the response body to the stream.  Given that we've
    // set the stream's sink to a file, it will stream directly
    // to the file.
    success := rest.ReadRespBodyStream(bodyStream.ControlInterface,1);
    if (success <> 1) then
      begin
        Memo1.Lines.Add(rest.LastErrorText);
        Exit;
      end;

    Memo1.Lines.Add('Successfully downloaded the file.');

  end
else
  begin
    errResponse := rest.ReadRespBodyString();
    if (rest.LastMethodSuccess <> 1) then
      begin
        Memo1.Lines.Add(rest.LastErrorText);
      end
    else
      begin
        Memo1.Lines.Add(errResponse);
      end;
  end;
end;