Swift

REST Receive Response in Chunks

See more REST Examples

Demonstrates how to receive a REST HTTP response in chunks.

Note: This example requires Chilkat 10.1.0 or greater.

Swift

func chilkatTest() {
    var success: Bool = false

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

    let rest = CkoRest()!

    // Connect to the web server
    var bTls: Bool = true
    var port: Int = 443
    var bAutoReconnect: Bool = true
    success = rest.connect(hostname: "chilkatsoft.com", port: port, tls: bTls, autoReconnect: bAutoReconnect)
    if success == false {
        print("\(rest.lastErrorText!)")
        return
    }

    // Send the request.
    // This can be *any* kind of request: POST, GET, PUT, etc. using *any* of the Chilkat REST methods that send requests.
    // For this example, we'll just GET a simple XML document that is about 274K in size.

    success = rest.sendReqNoBody(httpVerb: "GET", uriPath: "/hamlet.xml")
    if success == false {
        print("\(rest.lastErrorText!)")
        return
    }

    // Get the response header.
    var statusCode: Int = rest.readResponseHeader().intValue
    if statusCode < 0 {
        print("\(rest.lastErrorText!)")
        return
    }

    print("response status code = \(statusCode)")

    var outputFile: String? = "c:/temp/qa_output/hamlet.xml"

    let fac = CkoFileAccess()!
    success = fac.open(forWrite: outputFile)
    if statusCode < 0 {
        print("\(fac.lastErrorText!)")
        return
    }

    // Get the response in chunks.
    // (Note: There are more efficient ways to simply download a file from a web server, such as by calling Chilkat's Http.Download method.
    // The purpose of this method is to show how to receive a response chunk-by-chunk.)
    let bd = CkoBinData()!
    var status: Int = 1
    while status == 1 {
        // Read a minimum of 16000 bytes.
        // Note: Because of TLS message lengths, or the possibility of the response being either compressed (gzip/deflate) or in the HTTP chunked encoding,
        // the amount of data received in each call can be greater than the specified min size.
        // Chilkat will return from the call as soon as it has received an amount equal to or more than the specified size,
        // except for the very last chunk, which can be less that the min size or even 0 bytes.

        // The status will be one of three values:
        // -1 = error
        // 0 = received the last chunk of the response.
        // 1 = received a chunk, and more chunks are coming..

        // The received data is *appended* to the contents of the BinData object.
        status = rest.readRespChunkBd(minSize: 16000, bd: bd).intValue
        if status >= 0 {
            print("Received chunk: \(bd.numBytes.intValue) bytes")
            fac.fileWriteBd(binData: bd, offset: 0, numBytes: 0)
            bd.clear()
        }

    }

    fac.fileClose()

    print("Success.")

}