(PHP using ActiveX) XML Tree Traversal Order for Search* Methods

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>

Download Chilkat XML ActiveX

<?php

$xml = new COM("Chilkat.Xml");

//  The sample input XML is available at http://www.chilkatsoft.com/data/searchOrder.xml
$success = $xml->LoadXmlFile('searchOrder.xml');
if ($success != 1) {
    print $xml->lastErrorText() . "\n";
    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:
// xBeginAfter is a Chilkat.Xml
$xBeginAfter = null;
// xFound is a Chilkat.Xml
$xFound = $xml->SearchAllForContent($xBeginAfter,'*croc*');
while (!(is_null($xFound))) {

    print $xFound->tag() . "\n";

    // xBeginAfter is a Chilkat.Xml
    $xBeginAfter = $xFound;
    // xFound is a Chilkat.Xml
    $xFound = $xml->SearchAllForContent($xBeginAfter,'*croc*');
}


?>