PureBasic

XML Tree Traversal Order for Search* Methods

See more XML Examples

The Chilkat XML API provides a number of Search* methods for locating XML nodes based on criteria. These methods traverse an XML document in a breadth-first order. (See Breadth-First Search).

The XML document used in this example has the following tree structure:

The nodes are traversed in the order: A, B, C, D, E, F, G, H, I, J, K.

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

<a>crocodileA
    <b>crocodileB
        <d>crocodileD</d>
        <e>crocodileE
            <h>crocodileH</h>
            <i>crocodileI</i>
        </e>
    </b>
    <c>crocodileC
        <f>crocodileF</f>
        <g>crocodileG
            <j>crocodileJ</j>
            <k>crocodileK</k>
        </g>
    </c>
</a>

PureBasic

IncludeFile "CkXml.pb"

Procedure ChilkatExample()

    success.i = 0

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

    xBeginAfter.i
    xFound.i

    ; The sample input XML is available at http://www.chilkatsoft.com/data/searchOrder.xml
    success = CkXml::ckLoadXmlFile(xml,"searchOrder.xml")
    If success <> 1
        Debug CkXml::ckLastErrorText(xml)
        CkXml::ckDispose(xml)
        ProcedureReturn
    EndIf

    ; IMPORTANT:  The following loop for iterating over all 
    ; matching nodes performs reasonably well for small to 
    ; mid-size XML documents or sub-trees.  Performance
    ; can be poor when the sub-tree contains many thousands
    ; of nodes (or more).

    ; NOTE:  The search is always rooted at the calling node.
    ; In this example, it happens to also be the root node of the entire
    ; XML document.  Searches can be performed on sub-trees
    ; within the document by calling the Search* method from
    ; the root node of a sub-tree.

    ; Demonstrate the breadth-first traversal:
    xBeginAfter = CkXml::ckGetSelf(xml)
    xFound = CkXml::ckSearchAllForContent(xml,xBeginAfter,"*croc*")
    While (CkXml::ckLastMethodSuccess(xml) = 1)

        Debug CkXml::ckTag(xFound)

        CkXml::ckDispose(xBeginAfter)

        xBeginAfter = xFound
        xFound = CkXml::ckSearchAllForContent(xml,xBeginAfter,"*croc*")
    Wend

    CkXml::ckDispose(xBeginAfter)



    CkXml::ckDispose(xml)


    ProcedureReturn
EndProcedure