PureBasic

REST Read Binary Response into BinData Object (Amazon S3)

Demonstrates how to make a REST call that returns a binary response body. This example is valid for files that fit in memory. The example shows how to download a JPG from the Amazon S3 service. PureBasic

IncludeFile "CkBinData.pb"
IncludeFile "CkAuthAws.pb"
IncludeFile "CkRest.pb"

Procedure ChilkatExample()

    success.i = 0

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

    rest.i = CkRest::ckCreate()
    If rest.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; Connect to the Amazon AWS REST server.
    bTls.i = 1
    port.i = 443
    bAutoReconnect.i = 1
    success = CkRest::ckConnect(rest,"s3.amazonaws.com",port,bTls,bAutoReconnect)

    ; ----------------------------------------------------------------------------
    ; Important: For buckets created in regions outside us-east-1,
    ; there are three important changes that need to be made.
    ; See Working with S3 Buckets in Non-us-east-1 Regions for the details.
    ; ----------------------------------------------------------------------------

    ; Provide AWS credentials for the REST call.
    authAws.i = CkAuthAws::ckCreate()
    If authAws.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkAuthAws::setCkAccessKey(authAws, "AWS_ACCESS_KEY")
    CkAuthAws::setCkSecretKey(authAws, "AWS_SECRET_KEY")
    CkAuthAws::setCkServiceName(authAws, "s3")
    success = CkRest::ckSetAuthAws(rest,authAws)

    ; Set the bucket name via the HOST header.
    ; In this case, the bucket name is "chilkat100".
    CkRest::setCkHost(rest, "chilkat100.s3.amazonaws.com")

    ; Send the request to download the JPG.
    success = CkRest::ckSendReqNoBody(rest,"GET","/starfish.jpg")
    If success <> 1
        Debug CkRest::ckLastErrorText(rest)
        CkRest::ckDispose(rest)
        CkAuthAws::ckDispose(authAws)
        ProcedureReturn
    EndIf

    ; Read the response header.
    responseStatusCode.i = CkRest::ckReadResponseHeader(rest)
    If responseStatusCode < 0
        Debug CkRest::ckLastErrorText(rest)
        CkRest::ckDispose(rest)
        CkAuthAws::ckDispose(authAws)
        ProcedureReturn
    EndIf

    Debug "Response status code = " + Str(responseStatusCode)

    ; We expect a 200 response status if the JPG data is coming.
    ; Otherwise, we'll get a string response body with an error message(or no response body).
    If responseStatusCode <> 200
        errResponse.s = CkRest::ckReadRespBodyString(rest)
        If CkRest::ckLastMethodSuccess(rest) <> 1
            Debug CkRest::ckLastErrorText(rest)
        Else
            Debug errResponse
        EndIf

        CkRest::ckDispose(rest)
        CkAuthAws::ckDispose(authAws)
        ProcedureReturn
    EndIf

    bdBody.i = CkBinData::ckCreate()
    If bdBody.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkRest::ckReadRespBd(rest,bdBody)
    If success = 0
        Debug CkRest::ckLastErrorText(rest)
        CkRest::ckDispose(rest)
        CkAuthAws::ckDispose(authAws)
        CkBinData::ckDispose(bdBody)
        ProcedureReturn
    EndIf

    ; Save the contents of the response body to a file.
    success = CkBinData::ckWriteFile(bdBody,"qa_output/starfish.jpg")
    If success = 1
        Debug "Success"
    Else
        Debug "Failed to write file."
    EndIf



    CkRest::ckDispose(rest)
    CkAuthAws::ckDispose(authAws)
    CkBinData::ckDispose(bdBody)


    ProcedureReturn
EndProcedure