DataFlex

How to Avoid Large Strings in HTTP Responses

See more HTTP Examples

In some programming languages/environments, returning and passing large strings is problematic for both performance and other reasons (for example, with SQL Server limitations on sizes varchar variables).

One way of avoiding the need to return the actual string data, is to pass the data from one place to another via a Chilkat StringBuilder or BinData object. This example demonstrates a simple HTTP GET where the response body contains XML approximately 274K in size. The response body is loaded into the Chilkat.Xml without the XML content ever needing to leave the native code internal to Chilkat.

DataFlex

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Handle hoHttp
    Variant vResp
    Handle hoResp
    Variant vSb
    Handle hoSb
    Handle hoXml
    Boolean iBAutoTrim
    String sTemp1
    Integer iTemp1

    Move False To iSuccess

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

    Get Create (RefClass(cComChilkatHttp)) To hoHttp
    If (Not(IsComObjectCreated(hoHttp))) Begin
        Send CreateComObject of hoHttp
    End

    Get Create (RefClass(cComChilkatHttpResponse)) To hoResp
    If (Not(IsComObjectCreated(hoResp))) Begin
        Send CreateComObject of hoResp
    End
    Get pvComObject of hoResp to vResp
    Get ComHttpNoBody Of hoHttp "GET" "https://www.chilkatsoft.com/hamlet.xml" vResp To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoHttp To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get Create (RefClass(cComChilkatStringBuilder)) To hoSb
    If (Not(IsComObjectCreated(hoSb))) Begin
        Send CreateComObject of hoSb
    End
    // Copy the response body to sb.
    Get pvComObject of hoSb to vSb
    Get ComGetBodySb Of hoResp vSb To iSuccess

    Get Create (RefClass(cComChilkatXml)) To hoXml
    If (Not(IsComObjectCreated(hoXml))) Begin
        Send CreateComObject of hoXml
    End
    // Load the XML from the sb.
    Move False To iBAutoTrim
    Get pvComObject of hoSb to vSb
    Get ComLoadSb Of hoXml vSb iBAutoTrim To iSuccess

    Get ComLength Of hoSb To iTemp1
    Showln "The response body was " iTemp1 " characters in length."
    Showln "Success."

    // The output is:
    // 
    // 	The response body was 279658 characters in length.
    // 	Success.


End_Procedure