PHP and XML. Looping through an XML file with PHP

Question

I am knee deep in foreach purgatory right now trying to come up with a way to traverse this XML file (actual XML text below) with PHP(following the XML file content.) What I am trying to do is the following:

1. Get all folder element names
2. If the folder element has yes as a subfolder attribute, then move a level down and grab that folder element's name
3. If not move on to the next folder element

gallerylist.xml:

<?xml version="1.0" encoding="ISO-8859-1"?>
<gallerylisting exists="yes">
<folder subfolder="yes">
Events
   <folder subfolder="yes">
   Beach_Clean_2010
        <folder subfolder="no">
        Onna_Village
        </folder>
            <folder subfolder="no">
            Sunabe_Sea_Wall
        </folder>
        </folder>
  </folder>
  <folder subfolder="no">
  Food_And_Drink
  </folder>
  <folder subfolder="no">
  Inside
  </folder>
  <folder subfolder="no">
  Location
  </folder>
  <folder subfolder="no">
  NightLife
  </folder>
</gallerylisting>

gallerylisting.php

<?php
$xmlref = simplexml_load_file("gallerylisting.xml");
foreach($xmlref->children() as $child) {
    foreach($child->attributes() as $attr => $attrVal) {
        print $child;
        if($attrVal == "yes") {
            foreach($child->children() as $child) {
                echo $child;
                foreach($child->attributes() as $attr => $attrVal) {
                    if($attrVal == "yes") {
                        foreach($child->children() as $child) {
                            echo $child;
                        }
                    }                   
                }
            }
        }
    }
}

I am...counting...5 foreach loops deep into this PHP script and I do not like it at all, plus if my folders had another subfolder, I would have to add this same

$if(attrVal=="yes")...etc.

in again and well...no! Is there anyway at all that I can avoid this. I'm new to PHP, and especially PHP and XML.

Thanks for any help.

Answer 1

Recursion could be beneficial to you here.

<?php

function display_entities( $xml )
{
    foreach($xml->children() as $child) {
        foreach($child->attributes() as $attr => $attrVal) {
            print $child;
            if($attrVal == "yes") {
              display_entities( $child->children() );
            }
        }
    }
}

$xmlref = simplexml_load_file("gallerylisting.xml");

display_entities($xmlref->children());