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PureBasic

XML Document References

See more XML Examples

This example demonstrates the fact that the entire XML document remains in memory if at least one node is referenced. (It does not need to be the root node.)

Chilkat PureBasic Downloads

PureBasic
IncludeFile "CkXml.pb"

Procedure ChilkatExample()

    success.i = 0

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

    success = CkXml::ckLoadXml(xml,"<a><b>BBB</b><c>CCC</c></a>")

    Debug CkXml::ckGetXml(xml)

    ; We have the following XML stored in memory:

    ; 	<?xml version="1.0" encoding="utf-8"?>
    ; 	<a>
    ; 	    <b>BBB</b>
    ; 	    <c>CCC</c>
    ; 	</a>

    ; Get a reference to the 1st child.
    xB.i = CkXml::ckGetChild(xml,0)

    ; Re-load "xml" with an entirely new document:
    success = CkXml::ckLoadXml(xml,"<z><x>XXX</x></z>")

    ; What happens to xB?
    ; The answer is nothing.  xB still points ot the "b" node in the original document, and the entire
    ; original document remains in memory.  We now have two XML documents in memory.

    Debug CkXml::ckGetXml(xB)

    ; output is:

    ;     <b>BBB</b>

    ; Make xB reference the root node of its document:
    CkXml::ckGetRoot2(xB)
    Debug CkXml::ckGetXml(xB)

    ; You can see here that the entire original XML document is still available
    ; because at least one node in the XML is referenced by a variable.
    ; The output is:

    ;     <?xml version="1.0" encoding="utf-8"?>
    ;     <a>
    ;         <b>BBB</b>
    ;         <c>CCC</c>
    ;     </a>

    ; We can also see that "xml" contains an entirely new XML document:
    Debug CkXml::ckGetXml(xml)

    ;     <?xml version="1.0" encoding="utf-8"?>
    ;     <z>
    ;         <x>XXX</x>
    ;     </z>
    ; 

    CkXml::ckDispose(xB)



    CkXml::ckDispose(xml)


    ProcedureReturn
EndProcedure