PureBasic

Read the REST Response Body into BinData

Demonstrates Rest.ReadRespBd, which reads the response body as raw bytes into a BinData, replacing its previous contents.

The file paths are relative to the application's current working directory. Absolute paths may also be used. Supply the paths appropriate to your own environment.

Background. The staged request model separates sending from reading: a SendReq method transmits the request, ReadResponseHeader reads the status line and headers, and a ReadResp method reads the body. This gives fine control over large or streamed messages compared with the single-call full-request methods.

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PureBasic

IncludeFile "CkBinData.pb"
IncludeFile "CkStringBuilder.pb"
IncludeFile "CkRest.pb"

Procedure ChilkatExample()

    success.i = 0

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

    bTls.i = 1
    bAutoReconnect.i = 1
    success = CkRest::ckConnect(rest,"example.com",443,bTls,bAutoReconnect)
    If success = 0
        Debug CkRest::ckLastErrorText(rest)
        CkRest::ckDispose(rest)
        ProcedureReturn
    EndIf

    ;  The file paths are relative to the application's current working directory.  Absolute paths
    ;  may also be used.  Supply the paths appropriate to your own environment.

    success = CkRest::ckSendReqNoBody(rest,"GET","/api/images/1")
    If success = 0
        Debug CkRest::ckLastErrorText(rest)
        CkRest::ckDispose(rest)
        ProcedureReturn
    EndIf

    statusCode.i = CkRest::ckReadResponseHeader(rest)
    If statusCode < 0
        Debug CkRest::ckLastErrorText(rest)
        CkRest::ckDispose(rest)
        ProcedureReturn
    EndIf

    ;  Check for the expected success status code.  If the response is not 200, the body is likely
    ;  error text formatted as JSON, XML, or HTML rather than the expected binary content.  In that case
    ;  read the body as text, report it, and return.
    If statusCode <> 200
        sbError.i = CkStringBuilder::ckCreate()
        If sbError.i = 0
            Debug "Failed to create object."
            ProcedureReturn
        EndIf

        success = CkRest::ckReadRespSb(rest,sbError)
        If success = 0
            Debug CkRest::ckLastErrorText(rest)
            CkRest::ckDispose(rest)
            CkStringBuilder::ckDispose(sbError)
            ProcedureReturn
        EndIf

        Debug "Request failed with status code " + Str(statusCode)
        Debug CkStringBuilder::ckGetAsString(sbError)
        CkRest::ckDispose(rest)
        CkStringBuilder::ckDispose(sbError)
        ProcedureReturn
    EndIf

    ;  The status code is 200.  Read the response body as raw bytes into a BinData.
    bdResponse.i = CkBinData::ckCreate()
    If bdResponse.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkRest::ckReadRespBd(rest,bdResponse)
    If success = 0
        Debug CkRest::ckLastErrorText(rest)
        CkRest::ckDispose(rest)
        CkStringBuilder::ckDispose(sbError)
        CkBinData::ckDispose(bdResponse)
        ProcedureReturn
    EndIf

    bSaved.i = CkBinData::ckWriteFile(bdResponse,"qa_output/image.png")
    If bSaved <> 1
        Debug "Failed to save the response body."
        CkRest::ckDispose(rest)
        CkStringBuilder::ckDispose(sbError)
        CkBinData::ckDispose(bdResponse)
        ProcedureReturn
    EndIf

    Debug "Received " + Str(CkBinData::ckNumBytes(bdResponse)) + " bytes."


    CkRest::ckDispose(rest)
    CkStringBuilder::ckDispose(sbError)
    CkBinData::ckDispose(bdResponse)


    ProcedureReturn
EndProcedure