(Swift 2) 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 Downloads for the Swift Programming Language MAC OS X (Cocoa) Objective-C/Swift Libs iOS Objective-C/Swift Libs

func chilkatTest() {
    // 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 ..."
    var accessToken: String? = "EBAY_ACCESS_TOKEN"

    let http = CkoHttp()

    let req = CkoHttpRequest()

    req.HttpVerb = "POST"
    req.Path = "/FileTransferService"
    req.ContentType = "application/xml"

    // Build the XML body for the request.
    let xml = CkoXml()
    xml.Tag = "downloadFileRequest"
    xml.AddAttribute("xmlns", value: "http://www.ebay.com/marketplace/services")
    xml.UpdateChildContent("taskReferenceId", value: "50013004806")
    xml.UpdateChildContent("fileReferenceId", value: "50015579016")

    req.LoadBodyFromString(xml.GetXml(), charset: "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", value: "downloadFile")
    req.AddHeader("X-EBAY-SOA-SECURITY-TOKEN", value: accessToken)

    var resp: CkoHttpResponse? = http.SynchronousRequest("storage.sandbox.ebay.com", port: 443, ssl: true, req: req)
    if http.LastMethodSuccess != true {
        print("\(http.LastErrorText)")
        return
    }

    var statusCode: Int = resp!.StatusCode.intValue
    print("Response status code = \(statusCode)")

    let responseBody = CkoBinData()
    resp!.GetBodyBd(responseBody)
    resp = nil

    // 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.
    let mime = CkoMime()
    var success: Bool = mime.LoadMimeBd(responseBody)
    if success != true {
        print("\(mime.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.intValue != 2 {
        print("Expected the MIME to have 2 parts.")
        print("NumParts = \(mime.NumParts.intValue)")
        print("Failed.")
        return
    }

    // Get the XML from the 1st MIME sub-part.
    var part0: CkoMime? = mime.GetPart(0)
    var downloadResponseXml: String? = part0!.GetBodyDecoded()
    let xmlResp = CkoXml()
    xmlResp.LoadXml(downloadResponseXml)
    print("Download Response XML:")
    print("\(xmlResp.GetXml())")
    part0 = nil

    print("----")

    // Now get the zip from the second part (index=1), unzip, and examine..
    var part1: CkoMime? = mime.GetPart(1)
    let zipData = CkoBinData()
    // This example requires Chilkat v9.5.0.67 or later.
    // The GetBodyBd method was added in v9.5.0.67.
    part1!.GetBodyBd(zipData)

    // Check to see if we have a zip or gzip.
    let sbContentType = CkoStringBuilder()
    sbContentType.Append(part1!.ContentType)
    part1 = nil

    let xmlFromZip = CkoXml()

    if sbContentType.Contains("gzip", caseSensitive: false) == true {
        // This is a gzip compressed file.
        let gzip = CkoGzip()

        // in-place uncompress the data.
        // Note: The UncompressBd method was added in Chilkat v9.5.0.67
        success = gzip.UncompressBd(zipData)
        if success != true {
            print("\(gzip.LastErrorText)")
            return
        }

        xmlFromZip.LoadXml(zipData.GetString("utf-8"))

    }
    else {
        // This is a zip archive.

        // Load the body into a Zip object.
        let zip = CkoZip()
        success = zip.OpenBd(zipData)
        if success != true {
            print("\(zip.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.intValue != 1 {
            print("Expected the .zip to have 1 entry.")
            print("NumEntries = \(zip.NumEntries.intValue)")
            print("Failed.")
            return
        }

        var entry: CkoZipEntry? = zip.GetEntryByIndex(0)

        xmlFromZip.LoadXml(entry!.UnzipToString(0, srcCharset: "utf-8"))
        entry = nil
    }

    print("XML contained in the zip:")
    print("\(xmlFromZip.GetXml())")
    print("----")

    print("Success.")

}