Delphi DLL

Read the REST Response Body into BinData

Demonstrates Rest.ReadRespBd, which reads the response body as raw bytes into a BinData, replacing its previous contents.

The file paths are relative to the application's current working directory. Absolute paths may also be used. Supply the paths appropriate to your own environment.

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 DLL Downloads

Download Chilkat for Delphi DLL

Delphi DLL

var
success: Boolean;
rest: HCkRest;
bTls: Boolean;
bAutoReconnect: Boolean;
statusCode: Integer;
sbError: HCkStringBuilder;
bdResponse: HCkBinData;
bSaved: Boolean;

begin
success := False;

rest := CkRest_Create();
bTls := True;
bAutoReconnect := True;
success := CkRest_Connect(rest,'example.com',443,bTls,bAutoReconnect);
if (success = False) then
  begin
    Memo1.Lines.Add(CkRest__lastErrorText(rest));
    Exit;
  end;

//  The file paths are relative to the application's current working directory.  Absolute paths
//  may also be used.  Supply the paths appropriate to your own environment.

success := CkRest_SendReqNoBody(rest,'GET','/api/images/1');
if (success = False) then
  begin
    Memo1.Lines.Add(CkRest__lastErrorText(rest));
    Exit;
  end;

statusCode := CkRest_ReadResponseHeader(rest);
if (statusCode < 0) then
  begin
    Memo1.Lines.Add(CkRest__lastErrorText(rest));
    Exit;
  end;

//  Check for the expected success status code.  If the response is not 200, the body is likely
//  error text formatted as JSON, XML, or HTML rather than the expected binary content.  In that case
//  read the body as text, report it, and return.
if (statusCode <> 200) then
  begin
    sbError := CkStringBuilder_Create();
    success := CkRest_ReadRespSb(rest,sbError);
    if (success = False) then
      begin
        Memo1.Lines.Add(CkRest__lastErrorText(rest));
        Exit;
      end;
    Memo1.Lines.Add('Request failed with status code ' + IntToStr(statusCode));
    Memo1.Lines.Add(CkStringBuilder__getAsString(sbError));
    Exit;
  end;

//  The status code is 200.  Read the response body as raw bytes into a BinData.
bdResponse := CkBinData_Create();
success := CkRest_ReadRespBd(rest,bdResponse);
if (success = False) then
  begin
    Memo1.Lines.Add(CkRest__lastErrorText(rest));
    Exit;
  end;

bSaved := CkBinData_WriteFile(bdResponse,'qa_output/image.png');
if (bSaved <> True) then
  begin
    Memo1.Lines.Add('Failed to save the response body.');
    Exit;
  end;
Memo1.Lines.Add('Received ' + IntToStr(CkBinData_getNumBytes(bdResponse)) + ' bytes.');

CkRest_Dispose(rest);
    CkStringBuilder_Dispose(sbError);
CkBinData_Dispose(bdResponse);