(DataFlex) REST Stream Response to File (Streaming Download) (Amazon S3)

Demonstrates how to stream the response body directly to a file. (The example shows how to stream a JPG from the Amazon S3 service.)

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

Use ChilkatAx-win32.pkg

Procedure Test
    Handle hoRest
    Boolean iBTls
    Integer iPort
    Boolean iBAutoReconnect
    Boolean iSuccess
    Variant vAuthAws
    Handle hoAuthAws
    Integer iResponseStatusCode
    Variant vBodyStream
    Handle hoBodyStream
    String sErrResponse
    String sTemp1
    Boolean bTemp1

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

    Get Create (RefClass(cComChilkatRest)) To hoRest
    If (Not(IsComObjectCreated(hoRest))) Begin
        Send CreateComObject of hoRest
    End

    // Connect to the Amazon AWS REST server.
    Move True To iBTls
    Move 443 To iPort
    Move True To iBAutoReconnect
    Get ComConnect Of hoRest "s3.amazonaws.com" iPort iBTls iBAutoReconnect To iSuccess

    // ----------------------------------------------------------------------------
    // 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.
    Get Create (RefClass(cComChilkatAuthAws)) To hoAuthAws
    If (Not(IsComObjectCreated(hoAuthAws))) Begin
        Send CreateComObject of hoAuthAws
    End
    Set ComAccessKey Of hoAuthAws To "AWS_ACCESS_KEY"
    Set ComSecretKey Of hoAuthAws To "AWS_SECRET_KEY"
    Set ComServiceName Of hoAuthAws To "s3"
    Get pvComObject of hoAuthAws to vAuthAws
    Get ComSetAuthAws Of hoRest vAuthAws To iSuccess

    // Set the bucket name via the HOST header.
    // In this case, the bucket name is "chilkat100".
    Set ComHost Of hoRest To "chilkat100.s3.amazonaws.com"

    // Send the request to download the JPG.
    Get ComSendReqNoBody Of hoRest "GET" "/starfish.jpg" To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoRest To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Read the response header.
    Get ComReadResponseHeader Of hoRest To iResponseStatusCode
    If (iResponseStatusCode < 0) Begin
        Get ComLastErrorText Of hoRest To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Showln "Response status code = " iResponseStatusCode

    // 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 (iResponseStatusCode = 200) Begin

        Get Create (RefClass(cComChilkatStream)) To hoBodyStream
        If (Not(IsComObjectCreated(hoBodyStream))) Begin
            Send CreateComObject of hoBodyStream
        End

        // The stream's sink will be a file.
        Set ComSinkFile Of hoBodyStream To "qa_output/starfish.jpg"

        // Read the response body to the stream.  Given that we've
        // set the stream's sink to a file, it will stream directly
        // to the file.
        Get pvComObject of hoBodyStream to vBodyStream
        Get ComReadRespBodyStream Of hoRest vBodyStream True To iSuccess
        If (iSuccess <> True) Begin
            Get ComLastErrorText Of hoRest To sTemp1
            Showln sTemp1
            Procedure_Return
        End

        Showln "Successfully received the JPG file."

    End
    Else Begin
        Get ComReadRespBodyString Of hoRest To sErrResponse
        Get ComLastMethodSuccess Of hoRest To bTemp1
        If (bTemp1 <> True) Begin
            Get ComLastErrorText Of hoRest To sTemp1
            Showln sTemp1
        End
        Else Begin
            Showln sErrResponse
        End

    End



End_Procedure