Tcl

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>

Tcl

load ./chilkat.dll

set success 0

set xml [new_CkXml]

# xBeginAfter is a CkXml

# xFound is a CkXml

# The sample input XML is available at http://www.chilkatsoft.com/data/searchOrder.xml
set success [CkXml_LoadXmlFile $xml "searchOrder.xml"]
if {$success != 1} then {
    puts [CkXml_lastErrorText $xml]
    delete_CkXml $xml
    exit
}

# 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:
set xBeginAfter [CkXml_GetSelf $xml]
set xFound [CkXml_SearchAllForContent $xml $xBeginAfter "*croc*"]
while {[CkXml_get_LastMethodSuccess $xml] == 1} {

    puts [CkXml_tag $xFound]

    delete_CkXml $xBeginAfter

    set xBeginAfter $xFound
    set xFound [CkXml_SearchAllForContent $xml $xBeginAfter "*croc*"]
}

delete_CkXml $xBeginAfter


delete_CkXml $xml