(Delphi ActiveX) HTTP HEAD Request

Sends an HTTP HEAD request and gets the response.

Note: The response to an HTTP HEAD request is always just the response header. The reponse body is always 0 length (thus the reason it's called a "HEAD" request..)

Note: This example requires Chilkat v11.0.0 or greater.

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
success: Integer;
http: TChilkatHttp;
resp: TChilkatHttpResponse;
numHeaderFields: Integer;
i: Integer;

begin
success := 0;

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

http := TChilkatHttp.Create(Self);

// If the URL uses "https://", then the connection will be TLS.
// Otherwise it will be TCP.

// A failure is when we don't get any response.  It could be a timeout, an inability to connect, etc.
// For example, a "404 Not Found" response is still a response, and thus deemed success in terms of the API..

resp := TChilkatHttpResponse.Create(Self);
success := http.HttpNoBody('HEAD','https://example-code.com/',resp.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(http.LastErrorText);
    Exit;
  end;

// Examine the response.
Memo1.Lines.Add('Status Code = ' + IntToStr(resp.StatusCode));
Memo1.Lines.Add('Status Line = ' + resp.StatusLine);
Memo1.Lines.Add('Status Text = ' + resp.StatusText);
Memo1.Lines.Add('Full Response Header:');
Memo1.Lines.Add(resp.Header);
Memo1.Lines.Add('----');
numHeaderFields := resp.NumHeaderFields;
Memo1.Lines.Add('Num Header Fields: ' + IntToStr(numHeaderFields));

for i := 0 to numHeaderFields - 1 do
  begin
    Memo1.Lines.Add(resp.GetHeaderName(i) + ': ' + resp.GetHeaderValue(i));
  end;
end;