Lianja

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.

Lianja

llSuccess = .F.

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

loRest = createobject("CkRest")

// Connect to the web server
llBTls = .T.
lnPort = 443
llBAutoReconnect = .T.
llSuccess = loRest.Connect("chilkatsoft.com",lnPort,llBTls,llBAutoReconnect)
if (llSuccess = .F.) then
    ? loRest.LastErrorText
    release loRest
    return
endif

// 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.

llSuccess = loRest.SendReqNoBody("GET","/hamlet.xml")
if (llSuccess = .F.) then
    ? loRest.LastErrorText
    release loRest
    return
endif

// Get the response header.
lnStatusCode = loRest.ReadResponseHeader()
if (lnStatusCode < 0) then
    ? loRest.LastErrorText
    release loRest
    return
endif

? "response status code = " + str(lnStatusCode)

lcOutputFile = "c:/temp/qa_output/hamlet.xml"

loFac = createobject("CkFileAccess")
llSuccess = loFac.OpenForWrite(lcOutputFile)
if (lnStatusCode < 0) then
    ? loFac.LastErrorText
    release loRest
    release loFac
    return
endif

// 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.)
loBd = createobject("CkBinData")
lnStatus = 1
do while lnStatus = 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.
    lnStatus = loRest.ReadRespChunkBd(16000,loBd)
    if (lnStatus >= 0) then
        ? "Received chunk: " + str(loBd.NumBytes) + " bytes"
        loFac.FileWriteBd(loBd,0,0)
        loBd.Clear()
    endif

enddo

loFac.FileClose()

? "Success."


release loRest
release loFac
release loBd