Dart Requires Chilkat v11.0.0+

eBay -- Download Data using FileTransferService

See more eBay Examples

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

import 'package:chilkat/chilkat.dart';

void main() {
  // 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 ..."
  final accessToken = 'EBAY_ACCESS_TOKEN';

  final http = CkHttp();

  final req = CkHttpRequest();

  req.httpVerb = 'POST';
  req.path = '/FileTransferService';
  req.contentType = 'application/xml';

  // Build the XML body for the request.
  final xml = CkXml();
  xml.tag = 'downloadFileRequest';
  xml.addAttribute('xmlns', 'http://www.ebay.com/marketplace/services');
  xml.updateChildContent('taskReferenceId', '50013004806');
  xml.updateChildContent('fileReferenceId', '50015579016');

  req.loadBodyFromString(xml.getXml(), '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>

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

  final resp = CkHttpResponse();
  try {
    http.httpSReq('storage.sandbox.ebay.com', 443, true, req, resp);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  final statusCode = resp.statusCode;
  print('Response status code = $statusCode');

  final responseBody = CkBinData();
  resp.getBodyBd(responseBody);

  // 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.)
  responseBody.writeFile('qa_output/response.mime');

  if (statusCode != 200) {
    print('Failed.');
    return;
  }

  // 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.
  final mime = CkMime();
  try {
    mime.loadMimeBd(responseBody);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // 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 (mime.numParts != 2) {
    print('Expected the MIME to have 2 parts.');
    print('NumParts = ${mime.numParts}');
    print('Failed.');
    return;
  }

  // Get the XML from the 1st MIME sub-part.

  final part0 = CkMime();
  try {
    mime.partAt(0, part0);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  final downloadResponseXml = part0.getBodyDecoded();
  final xmlResp = CkXml();
  xmlResp.loadXml(downloadResponseXml);
  print('Download Response XML:');
  print(xmlResp.getXml());

  print('----');

  // Now get the zip from the second part (index=1), unzip, and examine..

  final part1 = CkMime();
  try {
    mime.partAt(1, part1);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  final zipData = CkBinData();
  part1.getBodyBd(zipData);

  // Check to see if we have a zip or gzip.
  final sbContentType = CkStringBuilder();
  sbContentType.append(part1.contentType);

  final xmlFromZip = CkXml();

  if (sbContentType.contains('gzip', false)) {
    // This is a gzip compressed file.
    final gzip = CkGzip();

    // in-place uncompress the data.
    // Note: The UncompressBd method was added in Chilkat v9.5.0.67
    try {
      gzip.uncompressBd(zipData);
    } on ChilkatException catch (e) {
      print(e.lastErrorText);
      return;
    }

    xmlFromZip.loadXml(zipData.getString('utf-8'));
  } else {
    // This is a zip archive.

    // Load the body into a Zip object.
    final zip = CkZip();
    try {
      zip.openBd(zipData);
    } on ChilkatException catch (e) {
      print(e.lastErrorText);
      return;
    }

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

    // The zip should contain a single XML file.
    if (zip.numEntries != 1) {
      print('Expected the .zip to have 1 entry.');
      print('NumEntries = ${zip.numEntries}');
      print('Failed.');
      return;
    }

    final entry = CkZipEntry();
    try {
      zip.entryAt(0, entry);
    } on ChilkatException catch (e) {
      print(e.lastErrorText);
      return;
    }

    xmlFromZip.loadXml(entry.unzipToString(0, 'utf-8'));
  }

  print('XML contained in the zip:');
  print(xmlFromZip.getXml());
  print('----');

  print('Success.');
}