DataFlex

Removing / Deleting Child Nodes from XML

See more XML Examples

Demonstrates various methods for removing child nodes from an XML document.

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>

DataFlex

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Handle hoXml
    Variant vXyz
    Handle hoXyz
    String sTemp1
    Integer iTemp1

    Move False To iSuccess

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

    // The sample input XML is available at http://www.chilkatsoft.com/data/fruit.xml
    Get ComLoadXmlFile Of hoXml "fruit.xml" To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoXml To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // The RemoveChild method removes (discards) all direct
    // children having the specified tag:
    Send ComRemoveChild To hoXml "fruit"

    // Show the resulting XML:
    Showln 'Result with all direct children having a tag equal to "fruit" removed:'
    Get ComGetXml Of hoXml To sTemp1
    Showln sTemp1

    // The XML with the "fruit" direct children removed is shown below:
    // Notice that the "fruit" node beneath "xyz" was not removed.
    // This correct because it was not a direct child of the calling node.

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

    // --------------------------------------------------------------------------
    // Restore the original XML:
    Get ComLoadXmlFile Of hoXml "fruit.xml" To iSuccess

    // The RemoveChildWithContent method removes the child
    // having the exact content specified, regardless of the tag.  
    // For example:
    Send ComRemoveChildWithContent To hoXml "pear"

    // Show the resulting XML:
    Showln 'Result with the node containing "pear" removed:'
    Get ComGetXml Of hoXml To sTemp1
    Showln sTemp1

    // --------------------------------------------------------------------------
    // Restore the original XML:
    Get ComLoadXmlFile Of hoXml "fruit.xml" To iSuccess

    // The RemoveChildByIndex method removes the Nth direct
    // child.  Indexing begins at 0.  The "xyz" child is at index 4:
    Send ComRemoveChildByIndex To hoXml 4

    // Show the resulting XML:
    // Notice that the entire "xyz" subtree is removed.
    Showln "Result with the node at index 4 removed:"
    Get ComGetXml Of hoXml To sTemp1
    Showln sTemp1

    // --------------------------------------------------------------------------
    // Restore the original XML:
    Get ComLoadXmlFile Of hoXml "fruit.xml" To iSuccess

    // Navigate to the node with tag "xyz"
    Get ComFindChild Of hoXml "xyz" To vXyz
    If (IsComObject(vXyz)) Begin
        Get Create (RefClass(cComChilkatXml)) To hoXyz
        Set pvComObject Of hoXyz To vXyz
    End

    // Remove the "xyz" subtree making it it's own XML document
    // with the "xyz" node at the root:
    Send ComRemoveFromTree To hoXyz

    // Show both XML documents:
    Get ComGetXml Of hoXyz To sTemp1
    Showln sTemp1
    Get ComGetXml Of hoXml To sTemp1
    Showln sTemp1

    // Also, the TreeId property is an integer value assigned
    // to nodes in an XML document.  All nodes belonging to
    // the same XML document will have the same TreeId.
    // Notice that the "xyz" node now has a different TreeId:
    Get ComTreeId Of hoXyz To iTemp1
    Showln "xyz TreeId = " iTemp1
    Get ComTreeId Of hoXml To iTemp1
    Showln "xml TreeId = " iTemp1

    Send Destroy of hoXyz


End_Procedure