Delphi ActiveX

Send a Staged REST Request from a StringBuilder

Demonstrates Rest.SendReqSb, which sends a request whose text body is read from a StringBuilder, then reads the response in separate steps.

Background. The staged request model separates sending from reading: a SendReq method transmits the request, ReadResponseHeader reads the status line and headers, and a ReadResp method reads the body. This gives fine control over large or streamed messages compared with the single-call full-request methods.

Chilkat Delphi ActiveX Downloads

Download Chilkat for Delphi ActiveX

Delphi ActiveX

var
success: Integer;
rest: TChilkatRest;
bTls: Integer;
bAutoReconnect: Integer;
sbBody: TChilkatStringBuilder;
statusCode: Integer;
responseBody: WideString;

begin
success := 0;

rest := TChilkatRest.Create(Self);
bTls := 1;
bAutoReconnect := 1;
success := rest.Connect('example.com',443,bTls,bAutoReconnect);
if (success = 0) then
  begin
    Memo1.Lines.Add(rest.LastErrorText);
    Exit;
  end;

rest.AddHeader('Content-Type','application/json');

//  Send a request whose text body is read from a StringBuilder.
sbBody := TChilkatStringBuilder.Create(Self);
sbBody.Append('{ "query": "chilkat" }');
success := rest.SendReqSb('POST','/api/search',sbBody.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(rest.LastErrorText);
    Exit;
  end;

//  After sending, read the response status line and header fields.  The return value is the HTTP
//  status code, or -1 if no response was received.
statusCode := rest.ReadResponseHeader();
if (statusCode < 0) then
  begin
    Memo1.Lines.Add(rest.LastErrorText);
    Exit;
  end;
Memo1.Lines.Add('Response status code: ' + IntToStr(statusCode));

//  Read the response body as text.
responseBody := rest.ReadRespBodyString();
if (rest.LastMethodSuccess = 0) then
  begin
    Memo1.Lines.Add(rest.LastErrorText);
    Exit;
  end;
Memo1.Lines.Add(responseBody);