PowerBuilder

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.

PowerBuilder

integer li_rc
integer li_Success
oleobject loo_Rest
integer li_BTls
integer li_Port
integer li_BAutoReconnect
integer li_StatusCode
string ls_OutputFile
oleobject loo_Fac
oleobject loo_Bd
integer li_Status

li_Success = 0

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

loo_Rest = create oleobject
li_rc = loo_Rest.ConnectToNewObject("Chilkat.Rest")
if li_rc < 0 then
    destroy loo_Rest
    MessageBox("Error","Connecting to COM object failed")
    return
end if

// Connect to the web server
li_BTls = 1
li_Port = 443
li_BAutoReconnect = 1
li_Success = loo_Rest.Connect("chilkatsoft.com",li_Port,li_BTls,li_BAutoReconnect)
if li_Success = 0 then
    Write-Debug loo_Rest.LastErrorText
    destroy loo_Rest
    return
end if

// 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.

li_Success = loo_Rest.SendReqNoBody("GET","/hamlet.xml")
if li_Success = 0 then
    Write-Debug loo_Rest.LastErrorText
    destroy loo_Rest
    return
end if

// Get the response header.
li_StatusCode = loo_Rest.ReadResponseHeader()
if li_StatusCode < 0 then
    Write-Debug loo_Rest.LastErrorText
    destroy loo_Rest
    return
end if

Write-Debug "response status code = " + string(li_StatusCode)

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

loo_Fac = create oleobject
li_rc = loo_Fac.ConnectToNewObject("Chilkat.FileAccess")

li_Success = loo_Fac.OpenForWrite(ls_OutputFile)
if li_StatusCode < 0 then
    Write-Debug loo_Fac.LastErrorText
    destroy loo_Rest
    destroy loo_Fac
    return
end if

// 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.)
loo_Bd = create oleobject
li_rc = loo_Bd.ConnectToNewObject("Chilkat.BinData")

li_Status = 1
do while li_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.
    li_Status = loo_Rest.ReadRespChunkBd(16000,loo_Bd)
    if li_Status >= 0 then
        Write-Debug "Received chunk: " + string(loo_Bd.NumBytes) + " bytes"
        loo_Fac.FileWriteBd(loo_Bd,0,0)
        loo_Bd.Clear()
    end if

loop

loo_Fac.FileClose()

Write-Debug "Success."


destroy loo_Rest
destroy loo_Fac
destroy loo_Bd