(Delphi DLL) eBay -- Download Data using FileTransferService

Demonstrates how to download a data file using the eBay File Transfer API.

Note: This example requires Chilkat v9.5.0.67 or later.

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

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Mime, ZipEntry, Gzip, HttpResponse, HttpRequest, BinData, StringBuilder, Zip, Xml, Http;

...

procedure TForm1.Button1Click(Sender: TObject);
var
accessToken: PWideChar;
http: HCkHttp;
req: HCkHttpRequest;
xml: HCkXml;
resp: HCkHttpResponse;
statusCode: Integer;
responseBody: HCkBinData;
mime: HCkMime;
success: Boolean;
part0: HCkMime;
downloadResponseXml: PWideChar;
xmlResp: HCkXml;
part1: HCkMime;
zipData: HCkBinData;
sbContentType: HCkStringBuilder;
xmlFromZip: HCkXml;
gzip: HCkGzip;
zip: HCkZip;
entry: HCkZipEntry;

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

// Use a previously obtained access token.  The token should look something like this:
// "AgAAAA**AQA ..."
accessToken := 'EBAY_ACCESS_TOKEN';

http := CkHttp_Create();

req := CkHttpRequest_Create();

CkHttpRequest_putHttpVerb(req,'POST');
CkHttpRequest_putPath(req,'/FileTransferService');
CkHttpRequest_putContentType(req,'application/xml');

// Build the XML body for the request.
xml := CkXml_Create();
CkXml_putTag(xml,'downloadFileRequest');
CkXml_AddAttribute(xml,'xmlns','http://www.ebay.com/marketplace/services');
CkXml_UpdateChildContent(xml,'taskReferenceId','50013004806');
CkXml_UpdateChildContent(xml,'fileReferenceId','50015579016');

CkHttpRequest_LoadBodyFromString(req,CkXml__getXml(xml),'utf-8');

// The XML body looks like this:

// 	<?xml version="1.0" encoding="UTF-8"?>
// 	<downloadFileRequest xmlns="http://www.ebay.com/marketplace/services">
// 	<taskReferenceId>50013004806</taskReferenceId>
// 	<fileReferenceId>50015579016</fileReferenceId>
// 	</downloadFileRequest>

CkHttpRequest_AddHeader(req,'X-EBAY-SOA-OPERATION-NAME','downloadFile');
CkHttpRequest_AddHeader(req,'X-EBAY-SOA-SECURITY-TOKEN',accessToken);

resp := CkHttp_SynchronousRequest(http,'storage.sandbox.ebay.com',443,True,req);
if (CkHttp_getLastMethodSuccess(http) <> True) then
  begin
    Memo1.Lines.Add(CkHttp__lastErrorText(http));
    Exit;
  end;

statusCode := CkHttpResponse_getStatusCode(resp);
Memo1.Lines.Add('Response status code = ' + IntToStr(statusCode));

responseBody := CkBinData_Create();
CkHttpResponse_GetBodyBd(resp,responseBody);
CkHttpResponse_Dispose(resp);

// We can save the response body to a file for examination if we get an unanticipated response.  
// (It's binary, so it won't open well in a text editor.)
CkBinData_WriteFile(responseBody,'qa_output/response.mime');

if (statusCode <> 200) then
  begin
    Memo1.Lines.Add('Failed.');
    Exit;
  end;

// The response body looks like this:

// 	--MIMEBoundaryurn_uuid_2B668636C1E17A4D4114925305818684241
// 	Content-Type: application/xop+xml; charset=utf-8; type="text/xml"
// 	Content-Transfer-Encoding: binary
// 	Content-ID: <0.urn:uuid:2B668636C1E17A4D4114925305818684242>
// 
// 	<?xml version='1.0' encoding='UTF-8'?>
// 	<downloadFileResponse xmlns="http://www.ebay.com/marketplace/services">
// 	<ack>Success</ack>
// 	<version>1.1.0</version>
// 	<timestamp>2017-04-18T15:49:41.868Z</timestamp>
// 	<fileAttachment>
// 	    <Size>587</Size>
// 	    <Data>
//                 <xop:Include xmlns:xop="http://www.w3.org/2004/08/xop/include" href="cid:urn:uuid:A37C3C73E994C267F11492530585522"/>
// 	    </Data>
// 	</fileAttachment>
// 	</downloadFileResponse>
// 	--MIMEBoundaryurn_uuid_2B668636C1E17A4D4114925305818684241
// 	Content-Type: application/zip
// 	Content-Transfer-Encoding: binary
// 	Content-ID: <urn:uuid:A37C3C73E994C267F11492530585522>
// 
// 	<the binary bytes of the zip start here...>
// 

// Load the binary response into a MIME object.
mime := CkMime_Create();
success := CkMime_LoadMimeBd(mime,responseBody);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkMime__lastErrorText(mime));
    Exit;
  end;

// Make sure we have 2 sub-parts.  The 1st sub-part is the XML response, the 2nd sub-part
// is the zip containing the data.

// Note: The 2nd sub-part can be a "zip" or "gzip".  These are two different file formats.
// A zip is indicated with a Content-Type header equal to "application/zip",
// whereas a gzip is indicated with a Content-Type header equal to "application/x-gzip"
if (CkMime_getNumParts(mime) <> 2) then
  begin
    Memo1.Lines.Add('Expected the MIME to have 2 parts.');
    Memo1.Lines.Add('NumParts = ' + IntToStr(CkMime_getNumParts(mime)));
    Memo1.Lines.Add('Failed.');
    Exit;
  end;

// Get the XML from the 1st MIME sub-part.
part0 := CkMime_GetPart(mime,0);
downloadResponseXml := CkMime__getBodyDecoded(part0);
xmlResp := CkXml_Create();
CkXml_LoadXml(xmlResp,downloadResponseXml);
Memo1.Lines.Add('Download Response XML:');
Memo1.Lines.Add(CkXml__getXml(xmlResp));
CkMime_Dispose(part0);

Memo1.Lines.Add('----');

// Now get the zip from the second part (index=1), unzip, and examine..
part1 := CkMime_GetPart(mime,1);
zipData := CkBinData_Create();
// This example requires Chilkat v9.5.0.67 or later.
// The GetBodyBd method was added in v9.5.0.67.
CkMime_GetBodyBd(part1,zipData);

// Check to see if we have a zip or gzip.
sbContentType := CkStringBuilder_Create();
CkStringBuilder_Append(sbContentType,CkMime__contentType(part1));
CkMime_Dispose(part1);

xmlFromZip := CkXml_Create();

if (CkStringBuilder_Contains(sbContentType,'gzip',False) = True) then
  begin
    // This is a gzip compressed file.
    gzip := CkGzip_Create();

    // in-place uncompress the data.
    // Note: The UncompressBd method was added in Chilkat v9.5.0.67
    success := CkGzip_UncompressBd(gzip,zipData);
    if (success <> True) then
      begin
        Memo1.Lines.Add(CkGzip__lastErrorText(gzip));
        Exit;
      end;
    CkXml_LoadXml(xmlFromZip,CkBinData__getString(zipData,'utf-8'));

  end
else
  begin
    // This is a zip archive.

    // Load the body into a Zip object.
    zip := CkZip_Create();
    success := CkZip_OpenBd(zip,zipData);
    if (success <> True) then
      begin
        Memo1.Lines.Add(CkZip__lastErrorText(zip));
        Exit;
      end;

    // Save the .zip to a file (so we can examine it for debugging if something is not as expected)
    CkBinData_WriteFile(zipData,'qa_output/ebay_data.zip');

    // The zip should contain a single XML file.
    if (CkZip_getNumEntries(zip) <> 1) then
      begin
        Memo1.Lines.Add('Expected the .zip to have 1 entry.');
        Memo1.Lines.Add('NumEntries = ' + IntToStr(CkZip_getNumEntries(zip)));
        Memo1.Lines.Add('Failed.');
        Exit;
      end;

    entry := CkZip_GetEntryByIndex(zip,0);

    CkXml_LoadXml(xmlFromZip,CkZipEntry__unzipToString(entry,0,'utf-8'));
    CkZipEntry_Dispose(entry);
  end;

Memo1.Lines.Add('XML contained in the zip:');
Memo1.Lines.Add(CkXml__getXml(xmlFromZip));
Memo1.Lines.Add('----');

Memo1.Lines.Add('Success.');

CkHttp_Dispose(http);
CkHttpRequest_Dispose(req);
CkXml_Dispose(xml);
CkBinData_Dispose(responseBody);
CkMime_Dispose(mime);
CkXml_Dispose(xmlResp);
CkBinData_Dispose(zipData);
CkStringBuilder_Dispose(sbContentType);
CkXml_Dispose(xmlFromZip);
    CkGzip_Dispose(gzip);
    CkZip_Dispose(zip);

end;