Question

I am attempting to display data an XML source, in a tree format, to display correct Parent -> Child relationship.

The problem is the child nodes can have multiple child’s themselves (there is no limit)

An example of the output that works in flash = http://fluffyduck.com.au/example-layout.jpg

I cannot replicate this in PHP / html however.
I have provided an example XML source here : http://www.fluffyduck.com.au/sampleXML.txt

With the help of some other people, a list of parent ID’s and their children, as follows :

<?php

$content = file_get_contents('http://www.fluffyduck.com.au/sampleXML.txt');
$xml = new SimpleXMLElement($content);

$users = array ();
myUserReader($xml->user, $users);

function myUserReader($node, &$users)
{
    if (array_key_exists("{$node['id']}", $users) === false)
    {
        $users["{$node['id']}"] = array ();
    }
    if (isset($node->user))
    {
        for ($key = 0; ($key < count($node->user)); $key++)
        {
            $user = $node->user[$key];
            if (!in_array("{$node['id']}", $users["{$node['id']}"]))
            {
                $users["{$node['id']}"][] = "{$user['id']}";
#                $users["{$node['id']}"][] = $user;
            }
            myUserReader($user, $users);
        }
    }
}

foreach ($users as $parent => $children)
{
    echo "{$parent}: " . implode(", ", $children) . "\n";
}
?>

I am unable to work out what code I need to parse the above results and display the information as per the attached image above.

I have contemplated converting the XML to an array, but still have the same trouble, the code I have tried for that is :

function xmlstr_to_array($xmlstr) {
  $doc = new DOMDocument();
  $doc->loadXML($xmlstr);
  return domnode_to_array($doc->documentElement);
}
function domnode_to_array($node) {
  $output = array();
  switch ($node->nodeType) {
   case XML_CDATA_SECTION_NODE:
   case XML_TEXT_NODE:
    $output = trim($node->textContent);
   break;
   case XML_ELEMENT_NODE:
    for ($i=0, $m=$node->childNodes->length; $i<$m; $i++) {
     $child = $node->childNodes->item($i);
     $v = domnode_to_array($child);
     if(isset($child->tagName)) {
       $t = $child->tagName;
       if(!isset($output[$t])) {
        $output[$t] = array();
       }
       $output[$t][] = $v;
     }
     elseif($v) {
      $output = (string) $v;
     }
    }
    if(is_array($output)) {
     if($node->attributes->length) {
      $a = array();
      foreach($node->attributes as $attrName => $attrNode) {
       $a[$attrName] = (string) $attrNode->value;
      }
      $output['@attributes'] = $a;
     }
     foreach ($output as $t => $v) {
      if(is_array($v) && count($v)==1 && $t!='@attributes') {
       $output[$t] = $v[0];
      }
     }
    }
   break;
  }
  return $output;
}

$moo = xmlstr_to_array($content);
print_r($moo);

However the same problem exists, I do not know how to cycle through and display the information in the correct Parent -> Child manner recursively.

Due to the way the data is constructed I also cannot work out how to retrieve a “single” entry out, if i could do that perhaps I could manually rebuild the tree, I’m not sure how as each record does not have a unique identifer.

Any help greatly appreciated.

Answer 1

Might be much better in this case to avoid DOM or SimpleXML, and instead use XSLT, as it was designed for handling recursion. Create a stylesheet, something like this:

$xslt=new SimpleXMLElement('<xsl:stylesheet version="1.0"
    xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

   <xsl:template match="*">
       <ul>
            <li><xsl:value-of select="local-name()"/>
             <xsl:apply-templates/>
            </li>
       </ul>
    </xsl:template>
</xsl:stylesheet>');

Then transform it using the built in XSL libraries for PHP (note that some machines may have compiled PHP to not have this built in, but it’s likely it is):

$content = file_get_contents('http://www.fluffyduck.com.au/sampleXML.txt'); 
$xml = new SimpleXMLElement($content); 
$xsl_processor = new XSLTProcessor(); 
$xsl_processor->importStylesheet($xslt); 
echo $xsl_processor->transformToXml($xml);

That’s just a simple case, but it should generate a long, unordered list of all the parents and their children, properly nested. Modify the “value-of” directive to pull out attributes, etc. that you may rather display instead.