(DataFlex) Traverse Direct Children via FirstChild / NextSibling, or LastChild / PreviousSibling

Demonstrates some ways to iterate over direct child nodes using the FirstChild / NextSibling and LastChild / PreviousSibling methods.

The input XML, available at http://www.chilkatsoft.com/data/fruit.xml, is this:

<root>
    <fruit color="red">apple</fruit>
    <fruit color="green">pear</fruit>
    <veg color="orange">carrot</veg>
    <meat animal="cow">beef</meat>
    <xyz>
        <fruit color="blue">blueberry</fruit>
        <veg color="green">broccoli</veg>
    </xyz>
    <fruit color="purple">grape</fruit>
    <cheese color="yellow">cheddar</cheese>
</root>

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

Use ChilkatAx-win32.pkg

Procedure Test
    Handle hoXml
    Variant vChild
    Handle hoChild
    Variant vNextSibling
    Handle hoNextSibling
    Variant vPrevSibling
    Handle hoPrevSibling
    Boolean iSuccess
    Boolean iBContinue
    String sTemp1
    String sTemp2

    Get Create (RefClass(cComChilkatXml)) To hoXml
    If (Not(IsComObjectCreated(hoXml))) Begin
        Send CreateComObject of hoXml
    End

    Get ComLoadXmlFile Of hoXml "qa_data/xml/fruit.xml" To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoXml To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Iterate over the direct children by using FirstChild / NextSibling
    Get ComFirstChild Of hoXml To vChild
    If (IsComObject(vChild)) Begin
        Get Create (RefClass(cComChilkatXml)) To hoChild
        Set pvComObject Of hoChild To vChild
    End
    Get ComLastMethodSuccess Of hoXml To iBContinue
    While (iBContinue = True)
        Get ComTag Of hoChild To sTemp1
        Get ComContent Of hoChild To sTemp2
        Showln sTemp1 " : " sTemp2
        Get ComNextSibling Of hoChild To vNextSibling
        If (IsComObject(vNextSibling)) Begin
            Get Create (RefClass(cComChilkatXml)) To hoNextSibling
            Set pvComObject Of hoNextSibling To vNextSibling
        End
        Get ComLastMethodSuccess Of hoChild To iBContinue
        Send Destroy of hoChild
        Move hoNextSibling To hoChild
    Loop

    Showln "-----"

    // Do the same, but with FirstChild2 / NextSibling2 to avoid
    // creating so many XML object instances:
    Get ComFirstChild2 Of hoXml To iSuccess
    While (iSuccess = True)
        Get ComTag Of hoXml To sTemp1
        Get ComContent Of hoXml To sTemp2
        Showln sTemp1 " : " sTemp2
        Get ComNextSibling2 Of hoXml To iSuccess
    Loop

    // Revert back up to the parent:
    Get ComGetParent2 Of hoXml To iSuccess

    Showln "-----"

    // Iterate in reverse order using LastChild / PreviousSibling
    Get ComLastChild Of hoXml To vChild
    If (IsComObject(vChild)) Begin
        Get Create (RefClass(cComChilkatXml)) To hoChild
        Set pvComObject Of hoChild To vChild
    End
    Get ComLastMethodSuccess Of hoXml To iBContinue
    While (iBContinue = True)
        Get ComTag Of hoChild To sTemp1
        Get ComContent Of hoChild To sTemp2
        Showln sTemp1 " : " sTemp2
        Get ComPreviousSibling Of hoChild To vPrevSibling
        If (IsComObject(vPrevSibling)) Begin
            Get Create (RefClass(cComChilkatXml)) To hoPrevSibling
            Set pvComObject Of hoPrevSibling To vPrevSibling
        End
        Get ComLastMethodSuccess Of hoChild To iBContinue
        Send Destroy of hoChild
        Move hoPrevSibling To hoChild
    Loop

    Showln "-----"

    // Do the same, but with LastChild2 / PreviousSibling2 to avoid
    // creating so many XML object instances:
    Get ComLastChild2 Of hoXml To iSuccess
    While (iSuccess = True)
        Get ComTag Of hoXml To sTemp1
        Get ComContent Of hoXml To sTemp2
        Showln sTemp1 " : " sTemp2
        Get ComPreviousSibling2 Of hoXml To iSuccess
    Loop

    // Revert back up to the parent:
    Get ComGetParent2 Of hoXml To iSuccess


End_Procedure