Simplexml is giving me the wrong results

Question

I have a simple xml below:

<?xml version="1.0" encoding="utf-8"?>
<catalogue>
  <category name="textbook" id="100" parent="books">
    <product id="20000">
      <author>Gambardella, Matthew</author>
      <title>XML Developer's Guide</title>
      <genre>Computer</genre>
      <price>44.95</price>
      <publish_date>2000-10-01</publish_date>
      <description>An in-depth look at creating applications
      with XML.</description>
    </product>
    <product id="20001">
      <author>Gambardellas, Matthew</author>
      <title>XML Developer's Guide</title>
      <genre>Computer</genre>
      <price>44.95</price>
      <publish_date>2000-10-01</publish_date>
      <description>An in-depth look at creating applications
      with XML.</description>
    </product>
  </category>
  <category name="fiction" id="101" parent="books">
    <product id="2001">
      <author>Ralls, Kim</author>
      <title>Midnight Rain</title>
      <genre>Fantasy</genre>
      <type>Fiction</type>
      <price>5.95</price>
      <publish_date>2000-12-16</publish_date>
      <description>A former architect battles corporate zombies, an evil sorceress,                  and her own childhood to become queen
      of the world.</description>
    </product>
  </category>
</catalogue>

I am using php simplexml library to parse it as follows: (note there are two category nodes. The first category contains two 'product' children. My aim is to get an array that contains those two children of first 'category'

$xml = simplexml_load_file($xml_file) or die ("unable to load XML File!".$xml_file);

//for each product, print out info
$cat = array();
foreach($xml->category as $category)
{
    if($category['id'] == 100)
    {
        $cat = $category;       
        break;
    }
}
$prod_arr = $category->product;

Here is the problem. I am expecting an array with two products children but its only returning one product. What am I doing wrong or is this a php bug? Please help!

Answer 1

For start, your XML file is not well defined. You should probably start and end it with <categories> tag.

Replace the last assignment with the following:

$prod_array = array();
foreach ($cat->product as $p) {
    $prod_array[] = $p;
}

Answer 2

$cat = array();
foreach ($xml->category as $category)
{
    $attributes = $category->attributes();
    if(isset($attributes['id']) && $attributes['id'] == 100)
    {
        $cat = $category;
        break;
    }
}

Answer 3

You can use SimpleXMLElement::xpath() to get all product elements that are children of a specific category element. E.g.

 // $catalogue is your $xml
 $products = $catalogue->xpath('category[@id="100"]/product');
 foreach($products as $p) {
   echo $p['id'], ' ', $p->title, "\n";
 }

prints

20000 XML Developer's Guide
20001 XML Developer's Guide